PREP 2021 Flashcards
What is persistent pulmonary hypertension of the newborn?
-PVR remains elevated after birth
-Prevents normal transition from fetal circulation to extrauterine circulation
Describe the flow of blood in a fetus?
-Oxygenated placental blood from umbilical vein into ductus venosus and caval circulation
-Majority of blood entering RA shunted across PFO by Eustachian valve to left heart and out to body
-Most of blood that enters RV and MPA goes R-L across ductus (because lungs are filled with amniotic fluid and not inflated the resistance to blood flow through pulmonary circulation is very high)
What causes closure of the ductus arteriosus and foramen ovale after birth?
-Pressures in pulmonary circulation decrease dramatically
-Results in less R-L shunting across PFO and PDA and leads to closure
What happens to the resistance in the pulmonary circulation in PPH?
It doesn’t drop- leads to pulmonary HTN
What is the reason for resistance in the pulmonary circulation failing to fall in PPHN?
-Not entirely understood
-Elevated vascular tone
-Abnormalities in the pulmonary vascular bed
-Pulmonary hypoplasia
-Some combination
What is the result of PPHN in the newborn?
-R-L shunting at PFO/PDA
-Hypoxemia that is minimally responsive to O2
What needs to be ruled in cases of suspected PPHN?
Cyanotic CHG like TAPVR
What is the general management strategy in PPHN?
-Reduce O2 demand (sedation)
-Increase PBF (optimize lung inflation, reduce PVR, treat underlying issues- infection, meconium aspiration, cardiac dysfunction, etc)
*Severe cases, may need ECMO until PVR improves
What is the fastest-onset therapy to quickly reduce PVR?
iNO
What is the Class I recommendations for reduction of PVR to prevent ECMO in PPHN in term or neat-term neonates with PPHN?
iNO
What type of medication is bosentan?
Endothelin receptor antagonist (pulmonary vasodilator)
How long does it take for bosentan to have effect?
5 hours (given enterally)
True or False: Bosentan is a treatment option for PPHN?
False- takes too long to have effect
What type of medication is Iloprost?
Inhaled (nebulized) prostacyclin analog
How long until iloprost reaches peak effect?
5 minutes (in inhaled form)
What are 2 ways that iloprost can be given?
Inhaled (nebulized)
IV
What are some problems with IV iloprost?
-Potential for systemic hypotension
-VQ mismatch
What are some problems with inhaled/nebulized iloprost?
-Irritate airways (because of carrier)
-Dosing less consistent because of loss into the nebulizer system
What is a Class IIb recommendation for refractory PPHN that doesn’t respond to iNO?
Inhaled iloprost
MOA sildenafil?
Phosphodiesterase 5 inhibitor
MOA milrinone?
Phosphodiesterase 3 inhibitor
True or False: Milrinone and sildenafil may be used to reduce PVR in an ill neonate with PPHN?
True
What are potential unwanted side effects of milrinone and sildenafil?
Lower systemic BP
When can sildenafil reach peak effect for lowering PVR?
Within 1-2 hours of administation
What medication is a Class IIa recommendation for refractory PPHN that doesn’t respond to iNO?
Sildenafil
How long does it take milrinone to reach steady state as an infusion?
6 hours
How long does it take for milrinone to have its effects on cardiac function and pulmonary vasodilation?
Within 1st hour (especially if given as bolus)
*Takes about 6 hours to steady state
What medication is a Class IIb recommendation in the setting of PPHN and LV dysfunction?
Milrinone
What is the first-line therapy for refractory persistent pulmonary HTN of the newborn to reduce PVR and reduce need for ECMO in term or near-term neonates?
iNO
What are adjunctive therapies to iNO for PPHN in the newborn?
-Sildenafil
-Inhaled prostacyclins
-IV milrinone
Prolonged QT interval with T-waves that are low in amplitude and notched?
LQTS-2
What causes LQTS-2?
Loss of function mutation in KCNH2 gene
When do patients with LQTS-2 have events?
Auditory triggers
Emotions
Sudden arousal
What should be considered for a patient with difficult-to-control seizures, but a normal EEG?
-LQTS
-When patients have an episode of torsades leading to a cardiac arrest, the resulting hypoxia can cause seizure-like activity (patients may be misdiagnosed as having a primary seizure disorder)
What is the treatment for patients with LQTS?
B-blockers (class II)
What type of beta-blockers are superior in LQTS to prevent cardiac events?
Non-selective (nadolol and propranolol)
*Versus the selective B-blockers like metoprolol
What is considered to be the 1st line therapy for patients with LQTS?
Nadolol
What should be considered in patients with aborted sudden death due to LQTS?
-ICD
+/-
-Left cardiac sympathectomy
What type of LQTS is triggered by auditory stimulus and sudden arousal?
2
-Consider removal of loud alarm clocks and use visual alarm clocks
How do class III antiarrhythmics (sotalol and amiodarone) work?
Prolong the action potential
Why are class III antiarrhythmics (sotalol and amiodarone) contraindicated in LQTS?
Prolong the action potential and prolong the QT interval
What are the preferred B-blockers in the management of LQTS?
Non-selective (nadolol, propranolol)
What are the triggers for cardiac events in patients with LQTS2?
Auditory and sudden arousal
What is due to a point mutation on the gene encoding for B-hemoglobin that causes the protein to polymerize in a relative deoxygenated environment, taking a sickle conformation and leading to vaso-occlusion?
Sickle cell disease
What is included under the umbrella sickle cell disease?
-Sickle cell anemia
-Sickle B-thalassemia
-Hgb SC disease
What is the general cardiac physiology of a patient with sickle cell disease?
Restrictive physiology superimposed on a high-output state
What are common echo findings in patients with sickle cell disease?
-Mildly elevated TR velocity
-LA and LV enlargement
-Increased LV mass
-LV diastolic dysfunction
*Some studies show dilation of all 4 heart chambers, but typically occurs later in life and kids only have left heart dilation
What effect on the cardiac system does the chronic anemia and hypoxemia caused by sickle cell disease have?
-LV dilation
-Increased stroke volume
-Increased CO
What causes the restrictive physiology seen in sickle cell disease?
LV diastolic dysfunction
What causes LV diastolic dysfunction in sickle cell disease?
Uncertain
-Fibrosis
-Increased mass
-Iron overload
-Increased aortic stiffness
LV diastolic dysfunction can lead to what problem in 60-10% of adult patients with sickle cell disease?
Pulmonary HTN
True or False: Systolic dysfunction is rare in patients with sickle cell disease (especially kids)
True
Patients with what disease have diastolic dysfunction superimposed on a high-output state?
Sickle cell disease
True or False: Systolic dysfunction is rare in patients with sickle cell disease?
True
Frequent multiform ventricular ectopy and nonsustained VT that is sometimes bidirectional?
CPVT
What is the differential diagnosis for bidirectional VT?
-CPVT
-LQTS-7 (Andersen-Tawil Syndrome)
-Digoxin toxicity
What patients experience episodes of VT in response to physical activity or emotional stress that places them at risk for sudden death?
CPVT
What is the most common genetic cause for CPVT?
Mutation in RYR2
*Less common is CASQ2
What protein is responsible for the Ca-induced Ca release from the SR?
RYR2
What is the result of mutations in the RYR2 gene?
-Leaky Ca channels that allow for extra Ca to be released from the SR during diastole
-Increases risk for delayed afterdepolarizations and ventricular arrhythmias
KCNH2 mutation?
LQTS2
For patients with LQTS2, most sudden death events are following what?
Sudden arousal triggers (alarm clock)
What is the class ventricular arrhythmia in LQTS?
Torsades de Pointes
What type of LQTS is associated with bidirectional VT?
LQTS-7 (Andersen-Tawil)
What is the mutation seen in LQTS-7 (Andersen-Tawil)?
KCNJ2
What are non-cardiac features seen in LQTS-7 (Andersen-Tawil)?
Periodic muscle paralysis and dysmorphic features
Mutations in MYH7 predispose patients to what?
HCM
Mutations in PKP2 predispose patients to what?
ARVC
Ventricular hypertrophy and abnormal T-waves on ECG?
HCM
ECG with ventricular hypertrophy and abnormal T-waves along with echo showing increased septal thickness, SAM and LVOTO?
HCM
ECG with epsilon waves and T-wave inversion in the right precordial leads V1-V3?
ARVC
*Echo can show enlarged diastolic RVOT and RV dilation/dysfunction
True or False: Mid-exertional syncope is concerning for underlying channelopathy or cardiomyopathy?
True
How can you tell if a P-wave with no QRS is a non-conducted PAC versus some type of AV block?
-See if P-P interval is same or shorter
-See if P-wave morphology is the same or different
Patients with situs ambiguous/heterotaxy may have what kind of rhythm?
Low atrial due to hypoplasia or absence of the sinus node
True or False: PJRT can’t sustain with a nonconducted P-wave?
True- PJRT is an AVRT, so both atria and ventricles are part of circuit
1st degree AV block?
Prolonged PR interval, but every P wave is conducted/followed by a QRS complex
Mobitz type 1 2nd degree AV block (AV Wenckebach)?
PR interval progressively prolongs before there is a non-conducted P-wave and the PR after the subsequent P-wave is shorter
Mobitz type 2, 2nd degree AV block?
Randomly non-conducted P-wave
True or False: Mobitz type 1 block is within the AV node and benign?
True
What is the concern with Mobitz Type 2 AV block?
Originates in the distal His-Purkinje conduction system… worse prognosis with likelihood of progressing to complete heart block (because it represents a diseased distal conduction system)
Why are patients with L-looped ventricles at risk of spontaneous complete heart block?
Long course of the AV bundle and fibrosis in the bundle of His
*AV block can occur in utero or during infancy
How does the risk of complete AV block increase in patients with L-TGA?
Linearly with age at a rate of 2%/year
There is a progressively increased risk of what in most patients with L-looped ventricles?
AV block
Progressive increase in PR interval before a non-conducted P-wave and subsequent P-wave is followed by a shorter PR interval with the ensuing QRS?
Mobtiz Type 1 2nd Degree AV block
True or False: Mobitz type 1 2nd degree AV block is generally benign?
True
True or False: Mobitz type 2 2nd degree AV block is more likely to progress to complete heart block (versus Mobtiz type 1 2nd degree AV block)?
True
Mobitz type 2 2nd degree AV block represents disease of what?
Distal His-Purkinje system
What is characterized by randomly non-conducted P-waves with no change in preceding PR interval?
Mobitz type 2 2nd degree AV block
In a fetal echo, what is seen arising from the MPA and inserting into the descending aorta?
Ductal arch (should have R-L shunting)
What is the purpose of the ductal arch in utero?
Less saturated blood in the RV bypasses the pulmonary circulation and is sent to the descending aorta to get to the placenta for gas exchange
What is the PVR and SVR in normal fetla physiology?
-PVR high
-SVR low
After birth, what happens to the PVR and SVR?
-PVR goes from high to low
-SVC goes from low to high
*Organ of gas exchange shifts from placenta to lungs
What is the Doppler profile commonly seen in the PDA on echos done DOL 1 reflecting normal newborn transition?
Bidirectional shunting
*Once umbilical cord clamped (neonate separated from low-resistance placental circulation), SVR rises acutely and aortic pressure increases
*Once lungs expand and ventilation starts, PVR falls and pulmonary blood flow increases
*R-L PDA flow in utero (due to PVR»SVR) transiently shifts to bidirectional
*One PVR continues to fall, the shunting becomes all L-R (but low velocity because PA pressures remain elevated)
Once the PVR has fully fallen a few weeks after birth, what type of Doppler would be seen from a PDA?
Continuous high velocity L-R shunting
*Versus low velocity L-R shunting seen in the more immediate newborn period as PA pressures still elevated
If there is persistent pulmonary hypertension, what type of Doppler would you see in a PDA?
Pure R-L
Describe the transition of fetal shunts (PDA and PFO) from in utero to after birth)
-In utero: R-L
-Immediately at birth: Bidirectional
-Shortly after birth: L-R
-Within several days: Close
PAPVR is a less appreciated, but well-described form of CHD in patients with what genetic diagnosis?
Turner
What is Turner syndrome caused by?
Complete or partial loss of on X chromosome (monosomy X)
What is the most common abnormality of sex chromosomes in females?
Turner (1/2500 live female births)
How is Turner syndrome often diagnosed?
-Prenatally with abnormal genetic screen
-Prenatally with abnormal US findings (increased nucal translucency)
-Evaluation for short stature
What types of CHD are seen in Turner Syndrome?
-Left sided heart lesions: Bicuspid AoV (25-30%), CoA (10-15%), HLHS (<5%)
-Transverse aortic arch elongation (up to 50%)
-PAPVR (25%)
-Persistent L-SVC to CS (15%)
-VSDs (5%)
-Persistent PDA (5%)
-Aortic dilation
What is different about the PAPVR seen in Turner v. general population?
-General population: PAPVR + sinus venosus ASD
-Turner: PAPVR without sinus venosus or any type of ASD
*ASD can occur in patients with Turner syndrome (5%), but PAPVR is more common
What do the physical findings in PAPVR depend on?
Degree of anomalous pulmonary venous drainage (variable)
What are some potential physical exam findings in PAPVR?
-Right heart dilation
-Widely-split 2nd heart sound
-Soft SEM at LUSB (relative PS)
*PAPVR can have normal variation of 2nd heart sound v. ASD usually having fixed splitting of S2
Under what condition can the aortic dilation seen in Turner syndrome be associated with aortic dissection?
Pregnancy
*Ao dilation common in Turner and may be progressive or associated with dissection
True or False: Practice guidelines for evaluation in patients with known Turner syndrome includes evaluation via CMR or CT to better assess ascending aorta and aortic arch and to evaluate for other congenital abnormalities (PAPVR) that may be missed by routine screening echo?
True- Once feasible without need for sedation
What are some risk factors for cardiovascular disease that are common in Turner syndrome?
-HTN (due to underlying horseshoe kidney)
-Obesity
-Dyslipidemia
-Type 2 DM
*Can also have sensorineural hearing loss and autoimmune disease like celiac
Isolated PAPVR is a common finding in patients with what?
Turner (up to 25% of patients)
The CND (via sympathetic/parasympathetic pathways) uses information from what to adjust HR and SVR?
Baroreceptors
Where are baroreceptors located?
-Carotid sinuses (bifurcation of internal/external carotids from common carotid)
-Aortic arch
What do the baroreceptors do?
Provide constant signals to the brain about BP
What is the Valsalva maneuver?
Exhale forcefully against a closed glottis
How does the Valsalva maneuver break SVT?
-Increases intrathoracic pressure
-Increases stimulation of aortic arch and carotid baroreceptors
-Results in greater parasympathetic stimulation to the AV node (increase in vagal tone)
-Slows conduction enough to interrupt re-entry circuit responsible for SVT and concert rhythm to sinus
Valsalva only works in what type of arrhythmias?
Ones where the AV node is part of the reentry circuit
What happens later in the Valsalva maneuver which also accounts for the reflex increase in HR seen with change in posture?
-Initially: Increased intrathoracic pressure at beginning of Valsalve decreases sympathetic venous return to heart, which leads to decreased CO and reduced arterial pressure
-Later: Decreased stimulation of aortic arch baroreceptors leads to increased sympathetic stimulation (increased vasoconstriction and HR) and decreased parasympathetic stimulation (elevated HR)
Where are chemoreceptors?
Carotid and aortic bodies
What is the primary function of chemoreceptors?
Regulate respiratory activity
What does increased stimulation of chemoreceptors do?
Increases sympathetic outflow to the CV system
Are chemoreceprots effected by the Valsalva maneuver?
Usually no… breath hold may cause enough change in PCO2 or PO2 to be detected by them, but the contribution is usually negligible (as compared to baroreceptor
How does the CNS monitor SBP?
Baroreceptors located in the carotid sinuses and aortic arch
How does the Valsalva maneuver increase parasympathetic output?
-Increases intrathoracic pressure
-Increases stimulation of the aortic arch baroreceptors
-Increases parasympathetic output
*Mechanism can be utilized to convert reentry tachyarrhythmias utilizing the AV node
What is involved in the initial stabilization of a neonate with HLHS after birth?
-Initiation of PGE (keep PDA open to ensure adequate PBF)
-Balance Qp:Qs as PVR drops
What is done in the initial palliation for HLHS?
Goal is stable shunted physiology
-Aortic arch reconstruction: Establish unobstructed systemic blood flow
-Anastomosis of the native aorta and PV to the Ao arch: Establish stable coronary perfusion and unobstructed RV-systemic flow
-Place AP or RV-PA shunt: Stable restricted pulmonary blood flow
-Atrial septectomy: Unobstructed pulmonary venous return or promote complete venous mixing
*Can also do hybrid procedures like PDA stents with PA band requiring no CPB
Rarely, neonates with HLHS can present with obstruction to pulmonary venous return at what level?
Atrial septum
What is a very poor prognostic sign in a newborn with HLHS?
Atrial restriction- Pulmonary congestion and damage to the vascular bed
What should be done for a neonate with HLHS and a restrictive atrial septum?
-Immediate atrial septostomy or septectomy to allow for pulmonary venous decompression and complete venous mixing
-Often very ill at birth
-If diagnosed in utero, consider delivery in OR or cath lab for immediate stabilization
True or False: Even with immediate atrial septostomy/septectomy, infants with HLHS and restrictive atrial septum have poor prognosis/outcomes?
True
What would be the effect of iNO in an infant with HLHS and restrictive atrial septum?
May make the pulmonary congestion worse (limitation in pulmonary blood flow isn’t at the pulmonary arteriolar level… it’s at the atrial septum)
What should be suspected in a neonate in extremis with HLHS?
Obstructed pulmonary venous return or inadequate atrial mixing
*Medical emergency
Patients with HLHS and inadequate venous mixing will require what at birth?
Cath or surgery for septostomy/septectomy
Low right atrial bradycardia, interrupted IVC and CS are consistent with left or right atrial isomerism?
Left atrial isomerism
True sinus rhythm isn’t common in which… left or right atrial isomerism?
Left- Sinus node may be absent or hypoplastic
What type of rhythm is often seen in patients with left atrial isomerism?
Slow ectopic atrial rhythms
Which type of isomerism is the IVC interrupted in approximately 78% of patients?
Left
How does the lower body typically drain in interrupted IVC?
-Usually via dilated azygous vein on right side of pine
*Can sometimes be a hemiazygous vein on left of spine
Describe the spleen in right atrial isomerism
-Absent in nearly 90% of patients (anatomical asplenia)
Describe the spleen in left atrial siomerism
Multiple spleens (88%)
*Up to 10% will have a solitary spleen
True or False: Even with splenic tissue in left atrial isomerism, it may not be normally functioning?
True
-Impaired splenic function in 12% with multiple spleens and 11% with solitary spleen
True or False: Both anatomical and functional asplenia predispose to infection and sepsis?
True
Anatomical and functional asplenia specifically predispose to infection by what type of bacteria?
Encapsulated
What should be recommended for patients with functional or anatomical asplenia?
-Prophylactic antibiotics (at least through age 5)
-Pneumococcal vaccines
*Some advocate for universal antibiotic prophylaxis in children with isomerism due to concerns for splenic function testing not being accurate or sensitive enough under 2 years of age
True or False: The best method of assessing splenic function isn’t well established?
True
What test can provide clues to the presence of absence of normal splenic function?
Peripheral blood smear
What are remnants of RBC nuclei that are normally removed by the spleen?
Howell-Jolly bodies
What can be found in the blood of patients who either don’t have a spleen (anatomical asplenia or history of splenectomy) or who have functional asplenia?
Howell-Jolly bodies
True or False: Howell-Jolly bodies can be found independently of the anatomical state of the spleen?
True
True or False: Howell-Jolly bodies can change with age?
True
True or False: Howell-Jolly bodies can transiently be found in otherwise healthy newborns?
True- Newborn state is a time of relative hyposplenism
What type of testing is an alternative method of assessing splenic function and may be superior to Howell-Jolly body testing?
Pitted RBC testing
A patient with left atrial isomerism is most likely to have polysplenia or asplenia?
Polysplenia
*Can see a normal appearing spleen or asplenia, but less likely
True or False: There are many instances of discordance between the status of the spleen and atrial arragement?
True- Asplenia/polysplenia don’t denote constant features of right v. left atrial isomerism and should only be used after radiologic evaluation
True or False: Patients with heterotaxy and isomerism of the atrial appendages are likely to have abnormal splenic morphology and reduced or absent splenic function?
True
All patients with isomerism should undergo what test to document the presence of absence of splenic tissue?
Abdominal US
All patients with anatomical or functional asplenia should receive what?
Antibiotic prophylaxis
What can be helpful to screen for splenic function in patients with isomerism and solitary or multiple spleens?
Peripheral blood smear to assess for Howell-Jolly bodies
How is Barth syndrome inherited?
X-linked recessive
What kind of disorder is Barth syndrome?
Mitochondrial myopathy
Cardiomegaly, neutropenia, skeletal myopathy, growth abnormalities?
Barth syndrome
Mutation in the tafazzin (TAZ) gene on Xq28?
Barth syndrome
What do mutations in the tafazzin (TAZ) gene on Xq28 result in?
Abnormalities in cardiolipin remodeling
What is the most common presenting feature in Barth syndrome?
Cardiomyopathy
Describe the cardiomyopathy in Barth syndrome
-Dilated
-LVNC
-HCM (less often)
-Most develop cardiomyopathy, 70% present within first year of life
What is the second leading cause of hospitalization in Barth syndrome (behind cardiac disease)?
Neutropenia (69% of patients)
Patients with what syndrome have neutropenia and are at increased risk for mouth ulcers, pneumonia and blood infections?
Barth
Describe growth in Barth syndrome?
-Length for boys is <3rd % on normative curve
-Catch-up growth happens after 12 years of age
Mutations in glucosidase alpha acid GAA) gene cause what?
Pompe
What is Pompe disease?
-Glycogen storage disease
-Abnormal production/function with acid alpha-glucosidase enzyme
How many types of Pompe are there and what makes them different?
-3
-Severity
-Age of appearance
What are the 3 types of Pompe?
-Classic infantile onset
-Non-classic infantile onset
-Late onset
Describe the classic form of infantile-onset Pompe
-Begins within 1st three months of life
-Associated with muscle weakness, hypotonia, hepatomegaly, HCM
Describe the non-classic form of infantile onset Pompe
-Appears by age 1
-Delayed motor skills, progressive muscle weakness
-Can have HCM, but less likely to present with heart failure
Describe late onset Pompe
-Occurs later in childhood or as an adult
-Progressive muscle weakness and/or respiratory failure
Mutations in lysosomal associated membrane protein 2 (LAMP2) cause what?
Danon disease
What is Danon disease?
-Lysosomal transport disorder
-Glycogen storage disease (type IIB)
*Without metabolic components classically associated with glycogen storage diseases
Are males or females more severely affected with Danon disease?
Males
What are the manifestations of Danon disease?
-Skeletal myopathy
-Mild intellectual disability
-Cardiomyopathy (usually HCM, but can see DCM)
Describe Danon disease in a female
-Can develop cardiomyopathy most often as adults (50% HCM, 50% DCM)
-Less likely to have skeletal myopathy or intellectual disabilities
Mutations in what is among the most common causes of cardiomyopathy in children?
Myosin heavy chain 7 (MYH7)
What is responsible for making beta-myosin heavy chain (protein found in cardiac muscle and type 1 skeletal muscles?
MYH7 gene
What is a common cause of autosomal dominant HCM (35% of cases), LVNC, DCM and RCM?
MYH7
Neutropenia + DCM or LVNC in a male?
Barth
How is Barth syndrome inherited?
X-linked
Mitochondrial myopathy associated with neutropenia, growth delay, skeletal myopathy, cardiomyopathy?
Barth
Mutation in tafazzin gene?
Barth
The tafazzin gene with is associated with Barth is involved in what?
Cardiolipin remodeling
What are the 3 types of Doppler echo?
-Color flow mapping (color)
-CW (spectral)
-PW (spectral)
What is used to describe relatively discrete flowing streams of blood in echo?
Spectral techniques
In echo, what helps guide the alignment of the spectral acquisition parallel to the angle of the jet of interest?
Color Doppler
Blood flow velocities are determined by the Doppler method and can be converted into a measurement of pressure using what?
“Simplified” Bernoulli equation
What is the simplified Bernoulli equation?
P = 4V2
The pressure from the simplified Bernoulli equation represents what?
Difference in pressure across the structure being interrogated
TR jet velocity 4.1M/sec, CVP 10mmHg, what is RVSP estimate?
(4*(4.1^2)) = 67mmHg + 10mmHg = 77mmHg
The RVSP and PASP are equal under what circumstance?
No RVOTO or PS
The RVSP is equal to the pressure difference between the RA and RV + what?
RA pressure
What is used as a surrogate for RAP?
CVP
What represents the difference in pressure between the PA and RV at end-diastole?
End diastolic PR velocity (converted into a pressure gradient)
RA pressure is a surrogate for RVEDP as long as…
There is no tricuspid stenosis
How can you calculate PA diastolic pressure by echo?
-End-diastolic PR velocity (into pressure gradient)… this is difference in pressure between PA and RV at end diastole
-RAP is surrogate for RVEDP with no TS
-PA diastolic pressure = Pressure gradient of end diastole PR velocity + RAP
How can you calculate mean PA pressure by echo?
-Use the peak early diastolic velocity of PR + RAP
To calculate the systolic, diastolic and mean PA pressure, you need what Doppler envelopes by echo?
TR and PR envelopes
Systolic = Pressure gradient of TR + RAP
Diastolic = Pressure gradient of end diastole PR velocity + RAP
Mean = Peak early diastolic velocity of PR + RAP
What are some of the common drugs utilized in the treatment of heart failure in 2V patients?
- Loop diuretics
- B-blockers
- ACEi
- Aldosterone antagonists
- Cardiac glycosides
Child with DCM presents with mild, persistent, dry cough, K level 5, otherwise normal renal function and electrolytes…. which medication is he likely taking?
ACEi
What are the effects of ACEi on preload, afterload and HR?
-Preload: Decrease
-Afterload: Decrease
-HR: No effect
What ultimately results in fluid retention and vasoconstriction in patients with heart failure?
-Upregulation of the production of renin due to decreased CO to the kidneys
-Starts cascade that causes fluid retention and vasoconstriction
What is an enzyme with proteolytic activity that cleaves angiotensinogen into angiotensin I?
Renin
What converts angiotensin 1 to angiotensin II?
Angiotensin-converting ensyme
What breaks down bradykinin?
Angiotensin-converting enzyme
What is bradykinin?
Vasodilator found primarily in the lungs
How does angiotensin II work?
Vasoconstrictor of precapillary arterioles and post capillary venules
The effects of angiotensin II exacerbate signs and symptoms of what problem?
Heart failure
How to ACEi work?
Block conversion of angiotensin I to angiotensin II
What are the effects of ACEi on arterioles and venules?
Vasodilation (via inhibition of angiotensin II which is a vasoconstrictor)
How do ACEi result in decreased afterload and preload?
Vasodilation of arterioles and venules by inhibition of angiotensin II (vasoconstrictor)
What are the effects of ACEi on the kidneys?
-Increased blood flow (due to vasodilation of the arterioles and venules)
-Results in increased diuresis
-Leads to decreased preload
What effect do ACEi have on the production of aldoesterone?
Initially decreased (because formation of angiotensin II is blocked)
Why do ACEi result in hyperkalemia?
-Aldosterone production is decreased
-Aldosterone is key to excretion of K in the kidneys… thus decreased aldosterone leads to decreased excretion of K in the kidneys and increased serum levels of K
True or False: Slightly increased levels of K don’t preclude the use of ACEi?
True… just need to monitor electrolytes
What causes the ACEi associated cough?
Inhibition of bradykinin metabolism
What are the effects of Angiotensin II?
-Cardiac and vascular hypertrophy
-Systemic vasoconstriction
-Increased blood volume (thirst)
-Renal, sodium and fluid retention
-Pituitary release of ADH leading to renal, sodium and fluid retention
-Adrenal cortex to release aldosterone leading to renal, sodium and fluid retention
What are common side effects of ACEi?
-Mild hyperkalemia
-Nonproductive dry cough
What are the effects of ACEi on preload and afterload?
Decrease
The ACC/AHA guidelines for sports participation are directed towards what?
Organized and competitive sports participation/training regimens in adolescents and adults
True or False: The ACC/AHA guidelines for sports participation are not meant to be an injunction against recreational physical activities or all forms of exercise and may not be applicable for preadolescent children?
True
True or False: Physical activity should be strongly promoted for most children and adolescents with CHD?
True
Within the AHA/ACC guidelines for sports participation, sports are classified on the basis what 2 things?
-Peak static component
-Peak dynamic component
What type of exercise is primarily a pressure load on the LV?
Static exercise
What type of exercise is primarily a volume load on the left ventricle?
Dynamic exercise
As the dynamic component of exercise increases from low (A) to moderate (B) to severe (C), what increases?
CO
As the static component of exercise increases from low (Class I) to moderate (Class II) to high (Class III), what increases?
BP load
How are sports placed into categories in the AHA/ACC sports participation guidelines?
On the basis of their combined dynamic and static components
Besides the dynamic/static components of a sport, what is the other category that is specifically recognized?
Those with a significant risk of bodily collision (probably high impact between competitors or between competitor and an object, including the ground)
In a patient with bicuspid AoV and aortic dilation, activity recommendations need to account for the risk of what?
Dissection
Dissection risk of the aorta is largely related to what?
Size of the aorta
*More activity restriction at larger vessel diameters
Wall stress on the aorta rises in proportion to what?
BP
BP during exercise is related to what?
Intensity of the exercise
*Higher intensity = Higher BP
Patients with bicuspid aortic valve and dilation of the aorta should limit the intensity of activity to what?
-Moderate intensity
*Need to limit intensity of activity, regardless of type with activities of moderate intensity being safe
Per the 2015 AHA/ACC guidelines, athletes with bicuspid AoV and mild-moderately dilated aorta and no features of associated connective tissue disorder can participate in what activities?
-Low and moderate static and dynamic sports with a low likelihood of significant bodily contact
*Avoidance of intense weight training should be considered
Per the 2015 AHA/ACC guidelines, athletes with bicuspid AoV and mild-moderately dilated aorta and no features of associated connective tissue disorder can do what type of weight training?
-If they desire participation in recreational resistance-type exercise like weight lifting, weights should be well below the 1-rep max
-Avoid Valsalva maneuver
What constitutes mild-moderate dilation of the aorta?
-Z-score 2-3.5
-Root or ascending aorta measuring up to 40-42mm in men or 36-39mm in women
Cycling, triathlon, rowing, gymnastics, weight lifting and wresting are all what type of sports?
High static
-Cycling, triathlon, rowing (IIIC)
-Gymnastics and weight lifting (Class IIIA)
-Wresting (Class IIIB)
Competitive baseball, gold and tennis can be considered for a patient with a mildly dilated ascending aorta?
True
Baseball (IB)
Golf (IA)
Tennis (IIC)
Competitive soccer, lacrosse and basketball would be discouraged for someone with a mildly dilated ascending aorta because of what?
Bodily impact is expected (not high static)
-Soccer (IC)
-Lacrosse and basketball (IIC)
True or False: Physical activity should be strongly promoted for most children and adolescents with CHD?
True
In patients with mild-moderate dilation of the aorta, activities of what intensity are generally safe?
Moderate
True or False: Society guidelines for sports eligibility and disqualification are directed towards organized/competitive sports participation and recreational physical activities?
False-
Not towards recreational physical activities
What is a common presentation in older patients with volume loading of the right heart (ASD or PAPVR)?
Atrial flutter
A chronic L-R shunt across an ASD with resultant atrial dilation/stretch predisposes patients who what?
Atrial tachyarrhythmias (atrial tachycardia, atrial flutter, atrial fibrillation)
What can eventually exacerbate atrial dilation in the setting of an untreated atrial level shunt?
TR due to annular dilation
True or False: Without intervention in childhood or young adulthood, atrial arrhythmias are common with a moderate-large ASD?
True
15% of patients by age 40
Over 50% of patients by age 60
True or False: Even with pre-operative atrial arrhythmias, atrial arrhythmias are less likely to recur after ASD closure?
True
*But, if atrial arrhythmias are present prior to ASD closure, there is an increased likelihood of recurrence
Which ASD patients have the lowest long-term risk of atrial arrhythmias?
-Surgical closure before 25 years and prior to sustained atrial tachycardias
What % of adults with an unrepaired ASD develop Eisenmenger physiology (long-term reversal of L-R shunt due to pulmonary HTN causing R-L shunting and cyanosis)?
10%
Which gender is Eisenmenger physiology due to an ASD more likely to occur in?
Females
Which is more common in unrepaired ASD, Eisenmenger or atrial arrhythmias?
Atrial arrhythmias
What is possible, but uncommon in patients with an atrial communication and intermittent R-L shunt?
Paradoxical embolus and stroke
Left to right atrial level shunting results in what problems for the RV?
-RV dilation
-Elevated filling pressure of the RV
True or False: It in uncommon for an unrepaired ASD to result in systolic dysfunction of the RV?
True
True or False: The RV volume will remodel quickly following ASD closure in young people with reduced end diastolic volume?
True
*Degree of remodeling appears to be inversely related to age at repair (argues for an early repair when detected)
Atrial arrhythmias (like flutter and fibrillation) are uncommon presenting signs of what in a child?
ASD
The natural history of unrepaired ASDs suggests progressive risk of what as patients age?
Arrhythmias (over 50% will have atrial arrhythmias without repair by middle to late adulthood)
In the setting of an ASD, what is associated with reduced risk of atrial arrhythmias and favorable long-term prognosis?
Early repair
True or False: Patients with repaired ToF (especially adults) are at risk of experiencing VT and SCD?
True
What are risk factors for SCD in ToF?
-QRS duration >180msec
-LV systolic or diastolic dysfunction
-NSVT
-Extensive RV scarring
-Inducible VT or V-fib on EP study
What can be helpful to reduce the number of ICD shocks related to VT in patients with ToF?
Ablation
Most VTs in patients with repaired ToF are what mechanism?
Reentrant
Describe the reentrant circuit which often causes VT in patients with repaired ToF
-Circuit contains critical areas of slowly conducting tissue (isthmuses) bordered by unexcitable tissue near the area of surgical intervention
-Slow conduction through the isthmuses allows time for repolarization of other parts of the circuit (no part of the circuit is refractory when encountered by the wavefront)
What are the 4 distinct isthmuses that are critically important in the reentrant circuits which cause VT in patients with repaired ToF?
-Between RVOT patch or ventriculotomy and TV annulus
-Between ventriculotomy and PV annulus
-Between VSD patch and PV annulus
-Between VSD patch and TV annulus
What 2 isthmus are most commonly responsible for inducible VT in repaired ToF?
-Between RVOT patch or ventriculotomy and the TV annulus (73%)
-Between the VSD patch and PV annulus (59%)
*Studies have shown that ablation at the identified critical isthmus successfully abolished the VT
If you can terminate VT with an ICD shock, it is unlikely to be due to what mechanism?
Ectopic focus (v. reentrant VT)
What are features of an isthmus that are associated with increased likelihood to sustain VT?
-Longer
-Narrower
-Lower voltage
-Conduct more slowly
True or False: Patients (especially adults) with repaired ToF are at risk of experiencing VT and SCD?
True
The mechanism of VT in patients with repaired ToF is typically what?
Reentrant
The reentrant VT seen in repaired TOF uses critical isthmuses bordered by unexcitable tissue from where?
-Ventriculotomy/outflow tract patch
-VSD patch
-TV annulus
-PV annulus
In patients with repaired ToF who have recurrent VT, what can be effective in treating VT?
Ablation
What is usually ligated during the surgical Glenn (cavopulmonary anastomosis) shunt?
Azygous
What is the effect of the persistence of an azygous vein after Glenn?
Venovenous pathway
*Shunts systemic venous blood (deoxygenated) from pulmonary circulation into systemic circulation- with higher pressures in Glenn circuit, can serve as a pop-cff with flow from SVC reversed through azygous draining to IVC and back to heart de-oxygenated
What is the effect of a large azygous vein after Glenn?
Significantly decreased systemic arterial saturations (serves as a venovenous pathway)
What should be done for a patent azygous vein found on cath after Glenn?
Transcatheter embolization
What is the normal position of the innominate vein?
Anterior to the ascending aorta
Describe the location of a retroaortic left innominate vein?
-More inferior than typical with subaortic course (versus normal position anterior to the ascending aorta)
A retroaortic left innominate vein is associated with that?
CHD and abnormalities of the aortic arch (present in 0.57 to 1.7% of patients with CHD)
A retroaortic left innominate vein is most commonly associated with what form of CHD?
ToF
Persistence of the azygous vein after the bidirectional Glenn shunt is a potential cause of what?
Progressive cyanosis
Retroaortic innominate vein is a rare venous anomaly that is usually associated with what?
CHD and aortic arch anomalies
Acute decompensated HF after viral illness?
Acute myocarditis
True or False: After the acute inflammatory phase of myocarditis, patients may have a slow recovery of their myocardial function, but many will continue have chronic HF with abnormal function and some will never recover function and may need transplant
True
What are 2 neurohumoral adaptations to decreased CO to maintain homeostasis?
-Sympathetic stimulation
-Activation of the renin-angiotensin-aldosterone system
What system increases renal salt resorption and intravascular water retention while also increasing vascular tone and promoting increased preload to the heart (potentially causing dysfunctional ventricular remodeling)?
Renin-angiotensin-aldosterone
Sympathetic activation in heart failure leads to what?
-Tachycardia
-Increased myocardial O2 demand
-Increased vascular tone
-Increased ventricular afterload
What are the effects of sympathetic activation in the setting of acute heart failure and chronic heart failure?
-Acute: Increase CO
-Chronic: Process continues to be activated and may interfere with myocardial recovery and induce maladaptive cardiac remodeling
Antagonism of what 2 systems is the mainstay of HF management in the outpatient setting?
-Renin-angiotensin-aldosterone
-Sympathetic stimulation
What 3 things are recommended for chronic heart failure management?
-Diuretic therapy to achieve euvolemia (Class I, Level C)
-Titrating ACEi to max tolerated safe dosing for symptomatic LV dysfunction (Class I, Level B)
-Consider mineralocorticoid antagonists for LV dysfunction (Class I, Level C)
How do diuretics, ACEi and mineralocorticoid antagonists counteract the dysregulated neurohhumoral cascade?
-Decongesting the heart
-Reducing LV afterload
-Improve endothelial dysfunction
-Promote cardiac remodeling
What can be considered for symptomatic LV dysfunction in heart failure?
B-blockers (Class IIa)
-Consider with chronic symptomatic HR with decreased EF
What are the typical first-line beta blockers used in heart faiure?
Carvedilol
Long-acting metoprolol
How does positive pressure ventilation reduce LV afterload?
Decreases the LV transmural pressure gradient
True or False: Invasive ventilation is a class I recommendation for acute inpatient heart failure with respiratory compromise?
True
True or False: Noninvasive ventilation is a class IIa recommendation for heart failure with respiratory distress
True
True or False: Supplemental O2 is beneficial in the management of chronic heart failure in the outpatient setting?
False- Can increase O2 delivery, but hasn’t been shown to be beneficial in the management of chronic HF in the outpatient setting
What is Bland-White-Garland syndrome?
ALCAPA
Why is coronary artery perfusion and saturation in ALCAPA normal in fetal circulation?
Pressure and O2 saturation in the pulmonary and aortic trunks are similar
What happens as fetal circulation transitions in a newborn with ALCAPA?
Fall of PA pressure leads to decreased coronary perfusion pressure and saturation of blood (O2 content)
What happens to infants with ALCAPA around 1-2 months of age?
Decreased coronary perfusion pressure and O2 content leads to coronary artery steal, progressive myocardial ischemia and LV dysfunction… results in ischemia and CHF symptoms
Which infants with ALCAPA might have delayed symptom presentation?
-Any with a delay in the normal fall of pulmonary pressure (infants living at altitude, PPHN, etc)
-If they develop collateralization of the coronary arteries
True or False: Some patients with ALCAP can remain relatively asymptomatic until adulthood (adult-type ALCAPA)?
True- Patients who develop robust collateralization
What are patients with adult-type ALCAPA at risk for?
-Heart failure
-Arrhythmias
-SCD due to chronic myocardial insufficiency, subendocardial ischemia, myocardial fibrosis
What are some of the presenting symptoms of ALCAPA?
-Young infant
-Colic (actually intermittent myocardial ischemia)
-Tachycardia
-Tachypnea
-Poor feeding
ECG with q waves in the lateral leads (I and avL)?
ALCAPA
How is the diagnosis of ALCAPA made?
Usually with just Echo, but sometimes CT or coronary angiography is used to confirm diagnosis and assess coronary collateral flow
What are the echo findings seen in ALCAPA?
-Reversed flow in the left main coronary artery on color Doppler
-Abnormal flow jet (LCA flow into the PA consistent with coronary run-off)
-Dilation of the right coronary artery
*LCA may appear to arise normally from aorta on 2D imaging, but have to confirm normal LCA flow by color Doppler
What are the typical non-coronary cardiac abnormalities by echo in ALCAPA?
-LV dilation with severely diminished LV systolic function
-Segmental wall motion abnormalities
-MR (due to combination of papillary muscle dysfunction/ischemic MR and annular dilation)
-Mitral papillary muscle and chordal apparatus may be bright (echogenic) due to presence of fibrotic changes with ischemia
What is the management of ALCAPA?
Prompt surgical repair at time of diagnosis
What are options for repair of ALCAPA?
-Re-implantation of anomalous LCA into aorta
-Takeuchi- Anomalous LCA baffled through transverse flap in MPA to aorta by creating an AP window
-Coronary artery bypass graft
True or False: The long-term prognosis of ALCAPA is generally good?
True- Even if they are very ill at presentation requiring ECMO
What is associated with a poorer prognosis following ALCAPA surgical repair?
Presence of moderate-severe MR
*Patients with significant post-op MR may need subsequent MV repair or replacement
What is the most common later surgical intervention required following ALCAPA repair?
MV repair (in patients who have significant MR)
What can be seen on CMR in the setting of ALCAPA?
Segmental myocardial fibrosis
True or False: LV aneurysm requiring resection is common following ALCAPA repair?
False
True or False: Ventricular function generally improves following ALCAPA repair?
True (when surgery performed during early infancy)
*Even in patients with severe ventricular dysfunction and segmental wall motion abnormalities
True or False: ALCAPA is a common reason for heart transplant?
False
What is a potential late complication of Takeuchi-type repair of ALCAPA?
Pulmonary artery stenosis at the site of the intra-pulmonary artery baffle
What historically was the original approach to ALCAPA?
Ligation of the LCA as a palliative technique to alleviate the coronary artery steal (v. surgical LCA re-implantation)
What needs to done via echo in all patients with decreased ventricular systolic function (especially infants)?
Color confirmation of coronary artery origin and proximal course
What is the definition of ventricular tachycardia?
Ventricular rhythm approximately 15% faster than the expected sinus rate
What is the definition of accelerated ventricular rhythm or accelerated idoventricular rhythm?
Ventricular rhythm with a rate that is within 10-15% of the underlying sinus rate
True or False: Accelerated ventricular rhythm in a newborn in the absence of any hemodynamic compromise, electrolyte abnormalities, systemic or metabolic illness and with no structural or functional cardiac abnormalities is a benign rhythm with an excellent prognosis?
True
What is the management of isolated accelerate ventricular rhythm in a newborn?
Reassurance… don’t require treatment because the arrhythmia resolves spontaneously within the first year after birth
Ventricular tachycardia in the neonatal period can be seen in association with what other findings?
-Electrolyte or metabolic abnormalities
-Structural heart defects or obstructive cardiac lesions
-Ventricular dysfunction/cardiomyopathy
-Myocarditis
-Cardiac tumors
-Channelopathies
What are some clues to point towards a ventricular rhythm versus aberrant supraventricular rhythm?
-AV dissociation
-Lack of ventricular preexcitation
Accelerated ventricular rhythm or accelerated idioventricular rhythm is diagnosed if the rate of ventricular rhythm is within what % of the underling sinus rate?
10-15%
What is the natural history of accelerated ventricular rhythm in the newborn with a structurally normal heart?
Benign with spontaneous resolution within the 1st year of life
What are the 2 hallmarks of managing a patients with acute cardiogenic shock?
Improve cardiac output
Reduce O2 demand
How can CO be improved in a patient with acute cardiogenic shock?
-Inotropic support
-Reduced afterload
-Improve cardiomechanical efficiency via Frank-Starling curve by decongestive therapy (diuretics)
-Correct reversible causes: Ischemia, arrhythmia, infection, obstruction
How can O2 demand be reduced in a patient with acute cardiogenic shock?
-Mechanical ventilation
-Sedation
-Control metabolic demands: Fever, sepsis, etc.
What medication is a catecholamine that has dose-dependent effects on chronotropy, inotropy and SVR related to the amount of A1 or B1 and B2 stimulation?
Dopamine
What are the effects of dopamine at lower doses (<10ug/kg/min)?
B1 and B2
-Increased HR (chronotropy)
-Increased contractility (inotropy)
What are the effects of dopamine at higher doses (>10ug/kg/min)?
A1 activation, conversion to norepinephrine
-Increased SVR (afterload)
Why might lowering a dose of dopamine result in clinical improvement for a patient in cardiogenic shock?
-Reduce afterload on a dysfunctional LV (via reduced A1 stimulation and decreased SVR)
How would lowering a dopamine infusion dose effect HR?
Lower- reduced B1 stimulation with lower doses
What do B2 receptors mainly act on?
Smooth muscle (relaxation)
What are the effects of epinephrine at lower doses?
Primarily B1 and B2 activation
What is an added effect of epinephrine at higher doses?
A1 (has primarily B1 and B2 activation at lower doses)
What are the primary effects of norepinephrine?
A1 activation (much less B1 and B2 activation
What medication has dose-dependent effects on chronotropy, inotropy and SVR related to the amount of A1 or B1/B2 stimulation?
Dopamine
What are the effects of dopamine at lower doses?
More B1/B2 activation… Increased HR (chronotropy) and increased contractility (inotropy)
What are the effects of dopamine at higher doses?
A1 activation and conversion to norepinephrine… significant increase in SVR (afterload)
What is the primary effect of epinephrine at lower doses?
B1 and B2 activation
Epinephrine has some stimulation of what at higher doses?
A1
What is the primary effect of norepinephrine?
A1 (much less B1 and B2)
Manifestations of early disseminated Lyme disease?
-Fevers
-Fatigue
-Carditis (complete AV block)
-Erythema migrans
-Cranial nerve palsy
-Meningitis
-Myopericarditis
-Arthralgias
Lyme carditis is reported in what % of patients with disseminated Lyme disease?
16% (although the overall incidence of Lyme carditis in all patients diagnosed with Lyme disease is low)
Lyme carditis is most likely to be seen in what children?
> 10 years
Arthralgias
Cardiopulmonary symptoms
In patients with Lyme carditis, almost half have evidence of what?
AV conduction deficits
What are some infectious procresses that can result in AV block?
-Lyme carditis
-Viral myocarditis
-Rheumatic cardiits
-Endocarditis
-Chagas disease
Which patients with Lyme carditis require hospitalization with telemetry and IV antibiotics?
-Symptomatic
-PR interval >300msec
-2nd or 3rd degree AV block
What is the drug of choice for patients with Lyme carditis who are hospitalized (complete AV block)?
Ceftriaxone
What medication is effective for patients with Lyme carditis who don’t require hospitalization and have a PR interval <300msec?
Doxycycline
What medications are used as 2nd line agents for patients intolerant of doxycycline or ceftriaxone for Lyme carditis?
Azithromycin or other macrolides
What might be required for a patient with significant AV block and severe symptoms due to Lyme carditis?
Temporary pacemaker
True or False: Most patients with Lyme-related AV block will recover conduction?
True
What time frame do most patients with Lyme-related AV block recover conduction?
Within 1 week once antibiotics started
*Permanent pacemakers not usually required
What is the treatment of choice for patients with Kawasaki?
IVIG
Describe the rash seen in Kawasaki
-Maculopapular, diffuse erythroderma or erythema multiforme-like rash
-Present on hands and feet
-Periungual desquamation
What is the goal of early post-op management following a Norwood?
Maximize ratio of O2 delivery to extraction… balance ratio of Qp to Qs as close to 1:1 as possible
What determines Qp:Qs in complete mixing physiology?
Relative resistance between the pulmonary and systemic circulations
What features of a BTT shunt have implications as to whether it acts as a resistor to the pulmonary circulation?
Length
Diameter
What results in an elevated Qp and potentially inadequate Qs in complete mixing physiology?
-Systemic to PA shunt with not enough resistance
-Low PVR
-High SVR
How does inadequate Qp manifest in complete mixing physiology?
Decreased systemic arterial O2 saturation
Inadequate Qp and decreased systemic saturations may result from what problems following a Norwood-BTT?
-Inadequate shunt perfusion pressure
-Restrictive atrial communication
-Pulmonary HTN
-Mechanical shunt obstruction
What is the most life-threatening cause of diminished pulmonary blood flow following at Norwood-BTT?
Shunt occlusion
What is typical management for shunt prophylaxis in Stage 1 patients?
-Heparin at low doses started 6-12 hours post-op
-Continue until patient can take ASA
How does acute shunt occlusion present?
-Profound hypoxia
-Cardiovascular collapse
What happens to the EtCO2 with acute shunt occlusion?
Decrease- Due to VQ mismatch
What should be done as part of medical management for acute shunt occlusion?
-Increase SVR to increase perfusion gradient across the shunt (epinephrine, norepinephrine, phenylephrine)
-Increase partial pressure of alveolar O2 (supplemental O2)
-Heparinization (50-100U/kg)
-Reduce O2 demand/consumption (sedation, muscle relaxation, mechanical ventilation)
-Call surgeon and ECMO teams
Why would increasing milrinone be contraindicated in the setting of acute shunt occlusion?
It would reduce SVR and perfusion gradient across the shunt
Why isn’t iNO effective in the setting of an acute shunt occlusion?
Cause of reduced Qp is a mechanical shunt obstruction and unrelated to PVR
How do you diagnose an acute shunt occlusion?
-Lack of a shunt murmur
-No flow across shunt on echo
The definitive assessment of shunt function with concern for occlusion requires what?
Angiography
What is the definitive management for acute shunt occlusion?
-Surgery
-Cath based intervention
True shunt occlusion frequent results in what?
Cardiac arrest with need for ECMO
What 3 things result in a larger portion of total CO being directed to the pulmonary circulation in the setting of stage 1 physiology?
-Inadequately resistant shunt
-Low PVR
-Elevated SVR
What are the manifestations of acute aortopulmonary shunt occlusion?
-Profound hypoxemia
-Decreased EtCO2 (if intubated)
-Subsequent cardiovascular collapse
-High likelihood of cardiac arrest
How is a left aortic arch with normal branching pattern demonstrated by echo?
-Cephalad course of first brachiocephalic vessel (innominate artery) originating from the arch is rightward and bifurcates into the right carotid and subclavian arteries
What is seen on echo with an aberrant right subclavian artery?
-First brachiocephalic vessel courses rightward, but bifurcation is unable to be visualized
-More caudally positioned pulsatile vessel courses rightward
True or False: An aberrant right subclavian artery is a benign vascular anomaly occurring in 0.5% of the population and typically has no clinical significance?
True
Describe the course of an aberrant right subclavian artery?
-Originates from upper descending thoracic aorta distal to the takeoff of the left subclavian artery
-Courses posterior to the esophagous
What is a possible cause of transient loss of right arm pulse during a TEE?
Aberrant right subclavian artery
What is the anatomy of a normal left-sided aorta?
-Aortic valve is positioned posterior and rightward of pulmonary valve
-Ascending aorta arises superior from center of heart and continues as transverse arch
-Transverse arch crosses over left mainstem bronchus and then downward with descending aorta coursing leftward and anterior of the spine
What is the anatomy of a right aortic arch defined by?
-Transverse arch that crosses over the right mainstem bronchus
-Descending aorta courses rightward and anterior to the spine
-Gradually courses to the left of the spine before reaching the level of the diaphragm
What defines arch sidedness by echocardiography?
The direction in which the first brachiocephalic artery courses cephalad
*Left arch when vessel courses rightward
*Right arch when vessel courses leftward
In a right aortic arch, when the first leftward vessel (left brachiocephalic artery) bifurcates into a left carotid artery and left subclavian artery, what is present?
Right aortic arch with mirror image branching
True or False: A right aortic arch with mirror image branching and arterial duct that inserts into the origin of the left brachiocephalic artery does not make a vascular ring?
True
In the setting of a right aortic arch with mirror image branching, what ligamentum insertion results in a vascular ring?
To the proximal descending aorta
A right aortic arch with an aberrant left subclavian artery forms a vascular ring due to what?
Insertion of the duct (ligamentum) on the proximal descending aorta at the base of the aberrant left subclavian
A normal left sided aortic arch is anatomically defined by what?
Transverse arch crossing over the left mainstem bronchus
A right aortic arch is anatomically defined by what?
Transverse arch crossing over the right mainstem bronchus
What defines arch sidedness by echo?
Direction in which the first brachiocephalic artery courses cephalad
*Right in left arch
*Left in right arch
How can an accessory pathway location bet determined during an EP study in patients with antegrade conducting accessory pathways?
Earliest ventricular activation
If there is earliest ventricular activation on the distal CS catheter during an EP study, where is the accessory pathway?
Mitral annulus
Where would a septal accessory pathway have earliest ventricular activation?
Proximal CS or His catheter (depending on where they are located on the septum)
Where would a right-sided accessory pathway have earliest ventricular activation during an EP study?
His catheter or proximal CS (depending on where they are located on the TV annulus)
True or False: Patients with preexcitation can have typical AVNRT as the cause of their tachycardia with a bystander AP?
True
How can you tell the difference between SVT due to AVNRT v. AVRT?
In AVNRT the ventriculoatrial timing is very short
During an EP study, the earliest site of ventricular activation during sinus rhythm in an antegrade conducting AP will be where?
At the site where the AP is located
Preexcitation is defined in intracardiac tracings by a His bundle-ventricular interval of what?
<30msec
What is a genetic cardiomyopathy caused by mutations in genes related to the cardiac desmosome?
ARVC
What structures are important in cell-to-cell adhesion?
Desmosome
What do the mutations in ARVC lead to?
Replacement of ventricular myocardium with fibrofatty tissue (usually right)
What are the specific proteins most often affected in ARVC?
-Desmoplakin
-Plakophilin 2
-Desmoglein 2
-Desmocollin 2
How are the pathogenic mutations in ARVC inherited?
AD
*Incomplete penetrance and variable expressivity are common
How does ARVC most commonly present?
Exertional syncope related to ventricular arrhythmias
*SCD can be first clinical manifestation
When does ARVC typically present?
2-4th decade
True or False: In advanced disease, RV or biventricular failure can occur due to ARVC?
True
How is definite ARVC diagnosed?
-2 Major
-1 Major and 2 Minor
-4 Minor
How is borderline ARVC diagnosed?
-1 Major and 1 Minor
-3 Minor
How is possible ARCH diagnosed?
-1 Major
-2 Minor
What are the categories of criteria for ARVC?
-Echo/MRI findings of RV dyskinesia/dilation
-Biopsy findings
-Family history
-ECG findings (repolarization abnormalities, depolarization/conduction abnormalities)
-Arrhythmias
True or False: Restriction from competitive and endurance sports is an important part of the treatment plan for patients with ARVC because frequent exercise can lead to progression of disease?
True
What are the AHA/ACC guidelines for sports participation in ARVC?
Restriction from all competitive sports with possible exception of low-intensity class 1A sports
*Many recommend activity restriction even in genotype +/phenotype - patients
What medications are utilized in ARVC?
-B-blockers: Decrease arrhythmia and RV wall stress (utility not well demonstrated)
-Class III antiarrhythmics: Decrease arrhythmia burden
True or False: Ablation can be helpful in select patients with ARVC?
True- Those with refractory, sustained, monomorphic VT
What is utilized for heart failure therapy in patients with ARVC?
-Standard heart failure therapy: ACEi, ARBs, B-blockers, Diuretics
ARVC is caused by mutations in genes related to what?
Cardiac desmosome (important in cell-to-cell adhesion)
What does ARVC lead to?
Replacement of ventricular myocardium with fibrofatty tissue (typically RV)
How does ARVC often present clinicall?
Exertional syncope or SCD related to ventricular arrhythmias, often presenting in the 2-4th decade
*RV or LV failure can occur in advanced stages of the disease
True or False: Restriction from competitive and endurance sports is an important part of the treatment plan for patients with ARVC because frequent exercise can lead to disease progression?
True
What are the major criteria on 2D echo for ARVC?
-Regional RV akinesia, dyskinesia or aneurysm
+ one of the following at end-diastole
-PLAX RVOT >32mm (>19mm/m2)
-PSAX RVOT >36mm (>21mm/m2)
-FAC <33%
What are the minor criteria on 2D echo for ARVC?
-Regional RV akinesia or dyskinesia
+ one of the following at end-diastole
-PLAX RVOT 29-32mm (16-19mm/m2)
-PSAX RVOT 32-36mm (18-21mm/m2)
-FAC 34-40%
What are the major criteria on MRI for ARVC?
-Regional RV akinesia or dyskinesia or dyssynchronous RV contraction + one of the following:
-Ratio of RVEDV/BSA >110mL/m2 (male) or >100mL/m2 (female
-RVEF <40%
What are the minor criteria on MRI for ARVC?
-Regional RV akinesia or dyskinesia or dyssynchronous RV contraction + one of the following:
-Ratio of RVEDV/BSA 100-110mL/m2 (male) or 90-100mL/m2 (female
-RVEF 41-45%
What are the major criteria for ARVC on RV angiography?
Regional RV akinesia, dyskinesia or aneurysm
What are the major criteria for ARVC by tissue characterization?
-<60% residual myocytes on morphometric analysis (or <50% if estimated)
-Fibrous replacement of RV free wall myocardium with or without fatty replacement of tissue in at least 1 endomyocardial biopsy sample
What are the minor criteria for ARVC by tissue characterization?
-60-75% residual myocytes on morphometric analysis (or 50-65% if estimated)
-Fibrous replacement of RV free wall myocardium with or without fatty replacement of tissue in at least 1 endomyocardial biopsy sample
What are the major criteria for ARVC by repolarization abnormalities?
-Inverted T waves in right precordial leads (V1, V2, V3) or beyond in patients >14 years (in absence of complete RBBB, QRS >120msec)
What are the minor criteria for ARVC by repolarization abnormalities?
-Inverted T waves in V1 and V2 in patients >14 years (in absence of complete RBBB) or in V4, V5 or V6
-Inverted T waves in leads V1, V2, V3 and V4 in patients >14 years (in presence of complete RBBB)
What are the major criteria for ARVC by depolarization and conduction abnormalities?
-Epsilon wave (reproducible low-amplitude signals from end of QRS complex to onset of T-wave) in right precordial leads (V1, V2, V3)
What are the minor criteria for ARVC by depolarization and conduction abnormalities?
-Late potentials on signal-averaged ECG in at least 1/3 parameters in absence on a QRS complex duration of >110msec on standard ECG
-Filtered QRS complex duration >114msec
-Duration of terminal QRS complex <40uV (low amplitude signal duration) >38msec
-Root mean square voltage of terminal 40msec <20uV
-Terminal activation duration of QRS complex >55msec (measured from nadir of S wave to end of QRS complex, including R’ in V1, V2 and V3 in absence of complete RBBB)
What are the major criteria for ARVC by arrhythmias?
-NSVT or VT with LBBB and superior axis pattern (negative or indeterminate QRS complex in II, III and aVF and positive QRS complex in aVL)
What are the major criteria for ARVC by arrhythmias?
-NSVT or VT of RVOT configuration with LBBB and inferior axis pattern (positive QRS complex in II, III and aVR and negative QRS complex in aVL) or unknown axis, or >500 ventricular extrasystoles/24 hours (Holter)
What are the major criteria for ARVC by family history?
-ARVC confirmed in a 1st degree relative who meets current criteria
-ARVC confirmed pathological at autopsy or surgery in 1st degree relative
-ID of pathogenic mutation categorized as associated or probably associated with ARVC in patient under evaluation
What are the minor criteria for ARVC by family history?
-History of ARVC in 1st degree relative in whom it isn’t possible/practical to determine whether current task-force criteria met
-Premature sudden death (at <35 years) due to suspected ARVC in 1st degree relative
-ARVC confirmed pathologically or by current task-force criteria in 2nd degree relative
What is a sign that aortic narrowing and hypertension are longstanding?
LV hypertrophy
How can coronary ostial stenosis lead to CHF and pulmonary edema?
MR via papillary muscle infarction
What is a chronic, relapsing inflammatory vasculitis of medium and large arteries, predominantly affecting the aorta and its branches?
Takayasu
Takayasu most often affects patients of what gender and age?
Women in their 30s
*But can be seen in infants as young as 6 months
What is the first stage of Takayasu?
-Pre-vasculitis phase
-Vague, non-specific symptoms for several years before the patient develops acute vascular symptoms
-Diagnosis of Takayasu is rarely considered
What is the 2nd stage of Takayasu arteritis?
-Overt vascular inflammatory changes
-Granulomatous lesions lead to stenosis, aneurysm formation, thrombosis or a combination anywhere in the aorta or its branches (less common in pulmonary arteries
-Elevated inflammatory markers (ESR, CRP)
-Possible hypercoagulable state
-Autoimmune abnormalities
Describe the 3rd stage of Takayasu arteritis?
Fibrosis develops- Symptoms may evolve into chronic vascular abnormalities (“burnt-out” stage)
CHF in Takayasu arteritis results from what?
-Acute LV afterload increase as inflammatory changes lead to rapid progression of aortic obstruction
-Less common, but can cause proximal coronary artery stenosis, myocardial ischemia, infarction, aortic insufficiency and acute MR due to papillary muscle infarct
What are some of the complications of Takayasu arteritis?
-Ischemic stroke
-Abdominal angina (mesenteric arteritis with abdominal pain after eating)
-Arterial rupture
-Arterial dissection
-Diminished or absent peripheral pulses with intermittent claudication
-Renal artery stenosis leading to HTN
What disease is referred to as the “pulseless disease”?
Takayasu- Diminished or absent peripheral pulses with intermittent claudication
-More typically seen in adults with longstanding Takayasu arteritis
How is Takayasu diagnosed?
Clinical and imaging findings- presence of typical vascular abnormalities
What is the most common presenting symptom of Takayasu in children?
HTN
What is needed for detailed vascular assessment when diagnosing Takayasu?
Advanced imaging (CTA, MRI, PET, ect)
Why would MRI or PET be more helpful in diagnosing Takayasu?
More detail regarding vessel wall inflammation and edema (indicative of active disease)
What is the first line therapy for Takayasu arteritis?
Steroids
*Can also use immunosuppressive agents like methotrexate and cyclophosphamide
What is often used for refractory or relapsing Takayasu?
Biological agents (like anti-tumor necrosis factor agent infliximab)
What is the differential diagnosis of Takayasu arteritis?
-Other forms of large-vessel inflammatory aortitis: Lupus and rheumatoid arthritis
-Syphilis
-TB
-Behcet
-Giant cell arteritis
Besides the coronary arteries, what other vessels can develop aneurysms in Kawasaki?
-Other arterial segments like the axillary or inguinal arteries
*Would be atypical to see stenosis in the large arteries like the aortic arch
What is chronic, relapsing vasculitis of the medium and large arteries that most commonly presents with obstruction and/or aneurysm of the aorta and its branches and/or renal arteries?
Takayasu
True or False: Takayasu arteritis can result in coronary artery and pulmonary artery stenosis?
True
What are symptoms of Takayasu arteritis?
-Nonspecific early
-Most commonly presents with HTN
-Can also present with CHF, MI, pulmonary edema or combination
How often should Fontan patient be seen and get echocardiograms?
-Visits every 6-12 months
-Echocardiograms annually
-End-organ function assessed at regular intervals
What are important tests to perform for end-organ dysfunction in Fontan patients?
-Hepatic function and fibrosis testing
-Renal function testing
-Pulmonary function testing
-Lymphatic testing and imaging
-Metabolic and endocrine function evaluation
-Hematologic system testing
-Neurologic evaluation
-Psychological evaluation
How often should end-organ testing be done in Fontan patients who are pre-teens, adolescents and adults?
-Pre-teen: 3-4 years
-Adolescents: 1-3 years
-Adults: 1-2 years
Routine testing for cardiac biomarkers (BNP) is recommended how often in Fontan patients?
-One during childhood
-Every 1-3 years in adolescents
-Every 1-2 years in adults
True or False: CT surgery should be avoided during pregnancy unless absolutely necessary?
True
True or False: Catheterization can be done in pregnancy in clinical instances when hemodynamic compromise or an emergent intervention requires either right-sided or full cardiac catheterization?
True
What are the risks to a fetus if Mom requires a catheterization during pregnancy?
-Radiation: Can limit exposure by short fluoroscopy times, reducing radiation dose as much as possible and provision of proper shielding
What is the Class IIa recommendation for percutaneous pulmonary valve replacement in a pediatric patient?
Reasonable to consider percutaneous pulmonary valve replacement in a patient with an RV-PA conduit with associated moderate to severe PI or PS provided patient meets inclusion/exclusion criteria or available valve
True or False: Current guidelines state that current transcatheter valve systems are designed to treat conduit and bioprosthetic valve failure only at this time and no intended to be used on patients who have undergone RVOT reconstruction by a transannular patch technique?
True
*But now several percutaneous valves that are approved or nearing approval for use in those without a conduit or bioprosthetic valve with right anatomic features
True or False: Pregnancy remains a relative contraindication to transcutaneous pulmonary valve placement, but the procedure may be necessary in selected patients with deteriorating clinical status?
True
What should you consider with an irregular narrow complex tachycardia?
A-fib
True or False: A-fib is uncommon in children?
True
What are the typical causes of a-fib in children?
-Most idiopathic
-Drug abuse
-Thyroid abnormalities
What can sometimes be seen in patients who were thought to have lone a-fib?
-An underlying AP or dual AV node physiology with inducible SVT
-Felt that a-fib was the result of SVT that degenerated into a-fib
What is a risk factor in the development of lone a-fib?
Obesity
*OSA also risk factor in adults, but no data on this in pediatrics
What is the treatment of choice for a-fib <48 hours?
Cardioversion
*DC at 0.5-1J/kg
*Medical: Flecainide or sotalol
How can adenosine be useful in a-fib?
-Unmask flutter waves or P-waves
-Won’t terminate arrhythmia because AV node isn’t part of circuit
What would be seen on rhythm strip if adenosine was given during atrial fibrillation?
-Pause in the ventricular rate
-Low-amplitude atrial electrical activity
Why is adenosine contraindicated if there is preexcitation and atrial fibrillation?
-Force conduction via accessory pathway and induce ventricular fibrillation
Transesophageal overdrive pacing can be useful in the treatment of what arrhythmias?
-SVT
-Atrial flutter
-IART
-Junctional rhythm
*Esophagus sits directly behind LA, so atrium can be captured with transesophageal pacing catheter
True or False: Transesophageal pacing can help terminate atrial firillation?
False- atrial electrical activity is disorganized… overdrive pacing won’t terminate tachycardia
Atrial fibrillation of unknown duration or lasting >48 hours has an associated risk of what?
Intracardiac thrombus
What is low cardiac output syndrome?
-Constellation of findings (elevated SVR, poor CO and O2 delivery) that usually occurs 6-12 hours after CPB
-End result of a long cascade of inflammatory reactions and neurohumoral activation combined with myocardial stunning from ischemia/reperfusion, as well as acute post-op physiological changes and fluid shifts
-Can result in CV collapse
True or False: In patients with ALCAPA (especially those with late diagnosis), ventricular function can take months to return to the normal range?
True
*These patients can be especially unstable in the acute post-op period
What is the equation for CO?
SV*HR
What does CO depend on?
HR and complex interplay of multiple factors (contractility/inotropy, preload, afterload… all affect SV)
What is preload?
State of cardiac filling at end diastole
What demonstrates the effect of preload on SV?
Frank-Starling curve
*When ventricular volume is low, SV is low
*When ventricular volume increases, SV increases
What happens at the inflection point on the Frank-Starling curve?
Point at which the ventricular end diastolic volume becomes too high, so the SV can no longer increase with further filling and becomes compromised due to overdistension and poor overlap of actin-myosin cross-bridges in stretched cardiac sarcomeres
What is afterload?
The force the ventricle must overcome to eject a volume of blood
In the setting of high afterload (left-sided obstructive lesion or elevated SVR), what is required to eject the same SV?
Compensatory mechanisms to enhance contractility
What depends on HR and a complex interplay of multiple factors (inotropy, preload, afterload) that augment the ventricular SV in the compensated state?
CO
*CO = SV * HR
What are some of the findings in low CO syndrome?
-Elevated SVR
-Reduced CO
-Reduced O2 delivery
When does low CO syndrome usually occur?
6-12 hours after CPB
What are the 2 lipid and lipoprotein disorders seen most frequently in children and adolescents?
-Familial combined hyperlipidemia (FCHL)
-Heterozygous familial hypercholesterolemia (FH)
What are of the most common disorders shown to be associated with atherosclerotic lesions in children and adolescents?
-Familial combined hyperlipidemia (FCHL)
-Heterozygous familial hypercholesterolemia (FH)
How does familial combined hyperlipidemia present?
-Elevated total cholesterol
-Elevated LDL
-Elevated TG
-Low HDL
How is familial combined hyperlipidemia inherited?
AD- Demonstrates phenotypic variability between family members
True or False: Familial combined hyperlipidemia often manifests with obesity?
True
What should be suspected in patients with elevated total cholesterol and LDL and normal TG and HDL and a family history of hypercholesterolemia (especially in children)?
Heterozygous familial hypercholesterolemia
What should be suspected with very high LDL levels (often >500mg/dL)?
Homozygous familial hypercholesterolemia (much rare that heterozygous)
What is the initial management for all children with hypercholesterolemia?
-Heart healthy lifestyle changes: Dietary modification, physical activity, weight loss for obese children, avoid nicotine exposure
What is the CHILD 2-LDL diet?
-25-30% of calories from fat
-At most 7% from saturate fat
-About 10% from monounsaturated fat
-Less than 200mg/dL intake of cholesterol
-Avoidance of trans fat as much as possible
True or False: Children with familial hypercholesterolemia commonly don’t respond sufficiently to dietary modification alone?
True- Most will require statin therapy with time
Statin medications are considered safe for children ages _ and above?
10 years
*In certain situations, may need to use a statin in a child below the age of 10
What are some of the adverse effects from stains?
-Myopathy
-Hepatic enzyme elevation
*Rare at standard doses
What monitoring is recommended for a child on a statin?
-Baseline creatine kinase, AST, ALT
-Follow-up AST and ALT and fasting lipid panel 4 weeks after initiation of therapy
*No need for repeat CK unless concern for myopathy present
What is considered acceptable, borderline-high and high total cholesterol levels in children and adolescents?
Acceptable: <170
Borderline-high: 170-199
High: >200
What is considered acceptable, borderline-high and high LDL cholesterol levels in children and adolescents?
Acceptable: <110
Borderline-high: 110-129
High: >130
What is considered acceptable, borderline-high and high non-HDL cholesterol levels in children and adolescents?
Acceptable: <120
Borderline-high: 120-144
High: >145
What is considered acceptable, borderline-high and high apolipoprotein B cholesterol levels in children and adolescents?
Acceptable: <90
Borderline-high: 90-109
High: >110
What is considered acceptable, borderline-high and high triglyceride levels in children 0-9 years?
Acceptable: <75
Borderline-high: 75-99
High: >100
What is considered acceptable, borderline-high and high triglyceride levels in children 10-19 years?
Acceptable: <90
Borderline-high: 90-129
High: >130
What is considered low, acceptable and borderline HDL cholesterol levels in children and adolescents?
Low: <40
Acceptable: >45
Borderline: 40-45
What is considered low, acceptable and borderline Apolipoprotein A-1 levels in children and adolescents?
Low: <115
Acceptable: >120
Borderline: 115-120
If the average of 2 fasting lipid profiles has a triglyceride level > what value should you consult a lipid specialist?
> 500
If the average of 2 fasting lipid profiles has a LDL level > what value should you consult a lipid specialist?
> 250
If the LDL is between what should you target lowering LDL?
Between 130-250
*Above 250 refer to lipid specialist
If the TG are between what should you target lowering TG?
<10 years: 100-500
>10 years: 130-500
*Above 500 refer to lipid specialist
After initiating lifestyle interventions for elevated cholesterol or triglycerides, how soon should you repeat a fasting lipid profile?
6 months
If LDL improves to goal range (<130) with lifestyle interventions after 6 months, how often should you repeat a fasting lipid profile?
Every 12 months
If LDL remains 130-189 after 6 months of lifestyle interventions, there is no family history and no other risk factors, what should you do?
-Continue Child-2-LDL diet
-F/U every 6 months with fasting lipid profile, family history and updated risk factors
If LDL remains >190 after 6 months of lifestyle interventions, what should you do?
Start statin
If LDL remains 160-189 with a +FHx or 1 high-level risk factor or 2+ moderate level risk factors after 6 months of lifestyle interventions, what should you do?
Start statin
If LDL is 130-159 with 2 high level risk factors or one high level and >2 moderate level risk factors or clinical CVD after 6 months of lifestyle interventions, what should you do?
Start statin
What should be done for a patient whom a statin has been started and the LDL is still <130?
If TG <200, refer to lipid specialist to add 2nd agent
What should be done for a patient in whom a statin has been started, LDL is improved, but non-HDL is remains elevated?
Target triglycerides
When you obtain 2 initial fasting lipid profiles to confirm hyperlipidemia, how far apart in time should they be obtained?
At least 2 weeks, no more than 3 months
A child who has an LDL above what would be considered for a shorter trial of lifestyle interventions than typically recommended (6months)?
> 190
What are the components of the CHILD-2-LDL diet?
-Refer to registered dietician for family medical nutrition therapy
-20-30% calories from fat
-<7% from saturated fat
-10% from monounsaturated fat
-<200mg/d of cholesterol
-Avoid trans fats
What are the supportive actions that are part of the CHILD-2-LDL diet?
-Plant sterol esters and/or plant stanol esters up to 2g/d as replacement for usual fat sources can be used after 2 year in children with familial hypercholesterolemia
-Plant stanol esters as part of a regular diet are marketed directly to public (short term studies with no harmful effects in kids
-Water-soluble fiber psyllium can be added to low-fat, low-saturated fat diet as cereal enriched with psyllium at a dose of 6g/d for 2-12 years and 12g/d for >12
-1 hour/day of moderate-vigorous physical activity and <2 hours/day of sedentary screen time
What are the components of the CHILD-2-TG diet?
-Refer to registered dietician for family medical nutrition therapy
-25-30% calories from fat
-<7% from saturated fat
-10% from monounsaturated fat
-<200mg/d of cholesterol
-Avoid trans fats
-Decrease sugar
-Replace simple with complex carbohydrates
-No sugar sweetened beverages
-Increase dietary fish to increase omega-3-fatty acids
What are factors that contribute to an increased risk for pregnant women with CHD?
-Increased preload
-Increased arterial compliance
-Increased HR
-Increased CO
-Initially decreased, then later increased BP
What are the 10 risk factors identified in the CARPREG II study that placed women with CHD at increased risk of maternal complications in peripregnancy?
-5 General:
*Prior cardiac events or arrhythmias
*Poor functional class or cyanosis
*High-risk valve disease/LVOTO
*Systemic ventricular dysfunction
*No prior cardiac interventions
-4 Lesion Specific:
*Mechanical valves
*High-risk aortopathies
*Pulmonary HTN
*CAD
-1 Delivery of Care:
*Late pregnancy assessment
What is a significant risk in patients who have undergone aortic arch repair using polyethylene terephthalate grafts (Dacron)?
Aortic aneurysm
*One study with freedom from aneurysm of 90% at 10 years and 42% at 25 years
*Almost 1/3 of those with aneurysms developed spontaneous rupture of aneurysm with most resulting in death
True or False: Volume lesions (like AI or VSD) are generally well tolerated during pregnancy in the absence of other underlying cardiac abnormalities?
True
All patients with CHD who are contemplating pregnancy should be screened for what?
Presence and/or severity of residual or recurrent heart defects
What is recommended in all adults with repaired thoracic aortic abnormalities?
CT or CMR (echo may be insufficiency to diagnose residual or recurrent defects)
In a Mom with 22q11.2 deletion, what is the % risk of the child have 22q11.2 deletion (with potential associated CHD)?
50%
Women with underlying repaired or unrepaired CHD should be screened for residual and/or recurrent cardiac lesions before what?
Any anticipated pregnancies
What women are at greatest risk of peripregnancy morbidity and mortality?
-Significant LVOTO: Suboartic or aortic stenosis, residual CoA
-Aortopathy
-Underlying pulmonary HTN
All adults who have undergone repair of thoracic aortic abnormalities should undergo what to assess for residual or recurrent stenosis and/or aneurysm?
Surveillance CT or CMR
What patients are at highest risk for aneurysm and even death due to aortic rupture?
-Patients who underwent aortic arch reconstruction using polyethylene terephthalate (Dacron) graft patch techniques
What type of medication is isoproterenol?
Non-selective B-agonist
What is isoproterenol used for?
Increasing HR in patients with symptomatic bradycardias, heart block and low CO states
What type of medication is propranolol?
Nonselective b-blocker
What is propranolol used for?
Management of arrhythmias and HTN
Anxiolytic
A drug that has the same effect at a lower drug concentration has a higher what?
Potency
A drug that has an improved response at a similar dose has a higher what?
Efficacy
If a drug requires a higher concentration to reach a similar effect, what might be the reason?
If a non-competitive antagonist was also being given
-Ex: Giving propranolol with isoproterenol will require more isoproterenol to get similar effect to isoproterenol alone
What alteration to the dose response curve would be seen if you added a partial agonist to a drug being given?
-Shifted to the right and decreased efficacy
*Partial agonists show both agonist and antagonist properties
What does it mean when the dose response curve foe a medication is shifted right?
-Require higher concentration to reach a similar effect
The interaction between competitive antagonists (like a B-blocker with B-agonist) would result in a shift of the dose-response curve what direction?
Right
What are the clinical manifestations of the interaction between competitive antagonists (like a B-blocker and B-agonist)?
-Higher dose of B-agonist to achieve increased HR
What is a non-cardiac use for B-blockers?
Anxiety
What are some of the features of a morphologic LV that can be seen on echo?
-Smooth walls (finely trabeculated)
-Mitral valve- 2 leaflets with elliptical orifice at midleaflet level, no chordal attachment to septum
What are some of the features of a morphologic RV that can be seen on echo?
-Coarse apical trabeculations
-Prominent muscle band at apical aspect (moderator band- crosses from IVS and inserts into free wall)
-Tricuspid valve- 3 leaflets, 1 will have chordal attachments to septum, triangular orifice at midleaflet level, chordal attachments to IVS
True or False: In heart with biventricular atrioventricular connections, the tricuspid valve is always found in the morphologic RV and the mitral valve is always found in the morphologic LV?
True- Valves follow ventricles
Atrioventricular valve morphology is more variable in what type of defects and is thus less helpful to define ventricular morphology?
Endocardial cushion defects
True or False: Ventricular position is independent of morphology?
True
If a right sided ventricle is the RV, what is the looping?
D-looped, right hand topology
If a right sided ventricle is the LV, what is the looping?
L-looped, left hand topology
True or False: PACs in fetal life in isolation are generally benign?
True
*Small % of fetuses with increased PACs are at risk for developing sustained tachyarrhythmias… require outpatient follow-up
What medication is helpful in treating fetal heart block, especially if there is maternal lupus or other autoimmune disorders?
Oral maternal dexamethasone
What medication can be used for fetal tachyarrhythmias… most commonly atrial flutter, but also SVT?
Sotalol
What should be considered with fetal dysrhythmias at late gestation if hydrops or other signs of significant fetal distress are present?
Delivery
What is the treatment for fetal PACs?
None- usually benign and don’t require treatment
How does CoA impact afterload?
Increases it
When CoA presents in infancy, how does it often present?
Significant illness with respiratory compromise
Neonates and infants with significant left-sided cardiac enlargement as a result of CHD may develop signs and symptoms of what?
Major airway compression
An elevation in LA pressure and PA pressure often results in what?
Airway compression- Left mainstem bronchus, LPA, left pulmonary veins and LA are closely related within the chest
What are the benefits of a baby grunting?
Compressed airways can be stented open as a result of PEEP generated within the larynx
If airway resistance is high, what does negative intrapleural pressure lead to?
Retractions of the pliable portions of the chest wall during inspiration (including subcostal and intercostal tissue)
Presence of metabolic acidosis and respiratory conditions that result in decreased compliance are common causes of what?
Tachypnea
What does hyperpnea refer to?
Rapid deep breathing
What is hyperpnea associated with?
Metabolic acidosis
True or False: Grunting and retractions are part of the compensatory mechanisms for metabolic acidosis in a baby?
False
What part of respiration is stridor heard in?
Inspiration
What type of CHD could cause stridor?
Compression of the trachea by an aortic arch anomaly like a vascular ring
What is an expiratory, high-pitched lung sound that results from oscillation of narrowed airway walls?
Wheezing
True or False: Any significant narrowing of the airway can result in wheezing?
True
True or False: Pulmonary venous edema due to high LA pressures can cause wheezing?
True- Narrowing of the small airways
“All that wheezes is not asthma”
Significant left-sided cardiac enlargement with LA and PA pressure elevation may result in compression of what?
Left mainstem bronchus (due to close relationship of the left mainstem bronchus to the LA and LPA
What is an LPA sling?
LPA arises from RPA rather than MPA
Why is an LPA sling not a true vascular ring?
-Surrounded anteriorly by MPA and rightward/posteriorly by LPA
-Leftward portion of the trachea isn’t compressed by any vessel
True or False: Respiratory symptoms with stridor in an infant is a common findings with an LPA sling?
True- can be severe especially if there are tracheobronchial tree abnormalities
What other congenital heart defects are associated with an LPA sling?
-ASD
-VSD
-PDA
-Persistent L-SVC to CS
-ToF
What is a Type 1 malformation or simple LPA sling?
-Anatomically normal trachea and bronchial bifurcation pattern
-1/3 of LPA slings
Symptoms in a type 1 LPA sling are due to what?
Airway narrowing caused by LPA compression on the trachea
What is a Type 2 malformation or complex LPA sling?
Complete cartilaginous tracheal rings and bronchial tree maldevelopment in addition to the anomalous vessel
What are some of the forms of tracheobronchial pathology seen in Type 2 LPA sling?
-Long-segment tracheal stenosis
-Narrowing of an intermediate bronchus leading to the left bronchus
-Partial or complete bronchial supply of the right lung via a bridging bronchus
*Complete supply of the right lung by a bridging bronchus is associated with hypoplasia of the right lung
What is required before surgical intervention for an LPA sling?
CTA- need to delineate the PA and tracheobronchial anatomy
True or False: Bronchoscopy is helpful to define airway anatomy in LPA sling?
False- Bronchoscopy can identify tracheal stenosis or complete rings, but airway narrowing won’t allow for assessment of the distal bronchial tree by bronchoscopy
What is seen on barium esophagram with an LPA sling?
Anterior indentation
What is the surgical management of a type 1 LPA sling?
Reimplantation of the LPA into the MPA
What are some of the options for management of a type 2 LPA sling?
-Careful assessment of airway anatomy by advanced imaging
-Slide tracheoplasty for tracheal stenosis
What is involved with a slide tracheoplasty for tracheal stenosis seen with a type 2 LPA sling?
-Transect at level of tracheal narrowing
-Vertical posterior/anterior incisions made on superior and inferior portions of trachea, respectively, then those portions are anastomosed
-Costal cartilage autograft and pericardial patch tracheoplasty often used in those with long segment stenosis
True or False: Morbidity and mortality are high in patients with LPA sling and complex airway anatomy?
True
What is an LPA sling?
Vascular anomaly in which LPA doesn’t arise from MPA, but from RPA
What causes symptoms in a Type 1 LPA sling?
Airway narrowing caused by LPA compression
True or False: A simple LPA sling (type 1) is associated with an anatomically normal tracheal and bronchial bifurcation pattern?
True
What is a complex LPA (type 2) sling associated with?
Complete cartilaginous tracheal rings and bronchial tree maldevelopment
*Symptoms, morbidity and mortality are often significant
What is a common organism for infective endocarditis and PDA associated infective endarteritis?
Strep viridans
What is the first step in management for PDA infective endarteritis?
IV antibiotics
After a full 6-week course of antibiotics and resolution of bacteremia, what should be done for PDA infective endarteritis?
Surgical or cath based closure of the PDA
*May consider closure prior to antibiotic completion if there is persistent bacteremia or septic emboli on therapy
What should be considered if there is septic pulmonary emboli related to endocarditis or endarteritis?
UFH
What age groups is PDA-associated infective endarteritis more commonly seen in?
-Older children and adults
-Rare in neonates
*Extremely rare overall
True or False: PDA infective endarteritis may affect patients with no residual PDA shortly after its regression?
True
True or False: PDA infective endarteritis can be life-threatedning?
True
PDA infective endarteritis is more common in patients with what exam finding?
Audible PDA
How does infective endarteritis present?
-Prolonged fever (weeks to months)
-Fatigue, heart failure, anorexia (if hemodynamically significant)
What are complications of PDA infective endarteritis?
Septic pulmonary or systemic emboli
True or False: Most cases of PDA infective endarteritis aren’t associated with other types of CHD?
True
What should be considered in an adult with fever and pulmonary infiltrates (after common causes have been excluded)?
Infective endarteritis
What are the 2 hypothesis for PDA infective endarteritis?
- Thrombus formation in the PDA as a substrate for vegetation
- Delayed PDA closure with endothelial inflammation resulting in increased risk of infection and subsequent thrombotic processes
What are sequelae of ductla endarteritis?
-Embolization to the lung with infarction
-PA endarteritis
-Aneurysm formation
-Aortitis
-Extension to the semilunar valves
-Death
What 2 tests are helpful to diagnose PDA endartertisi?
-Echo
-CTA- asses for pulmonary burden from septic emboli
What piece of management is critically important to reduce morbidity and mortality from PDA infective endarteritis?
IV antibiotics
How does invasive mechanical ventilation affect cardiac function and mechanics?
-Cardiopulmonary interactions from positive intrathoracic pressure and distension of alveoli beyond or below the functional residual capacity
-Augmentation of preload and afterload on each ventricle
What happens to intrathoracic pressure during negative pressure ventilation?
It is low
What is the effect on RV preload during inspiration in negative pressure ventilation?
-Improvement in RV preload due to improved venous return
-Intrathoracic pressure in inspiration is low during negative pressure ventilation
What are the effects on RV preload and afterload with positive pressure ventilation?
-Reduced preload
-Increased afterload (elevated intrathoracic pressure directly contribute)
Besides the effect of elevated intrathoracic pressure leading to increased RV afterload, what is another example of how positive pressure ventilation and worsen RV afterload?
-If the patient isn’t at FRC (either due to overinflation or atelectasis) the PVR is further increased and worsened RV afterload
What are important ventilation strategies in patients with right-sided heart disease (RV systolic or diastolic failure, Glenn or Fontan circulation)?
-Negative inspiratory ventilation
-Lower mean airway pressure
-Avoidance of mechanical pulmonary over or under inflation (which can increase PVR)
What is the effect of positive pressure ventilation on LV afterload?
-Reduces afterload
*Positive intrathoracic pressure reduces LV transmural pressure and thus, LV afterload
Positive pressure ventilation can benefit what types of heart disease?
Left-sided lesions (LV dysfunction, severe MR or AI) by reducing LV transmural pressure and LV afterload
What are the effects of overdistension or atelectasis on LV preload?
Transiently impart LV preload
What type of cardiac disease would you suspect in a patient whose hemodynamics improved with weans in mean airway pressure on the ventilator and eventual extubation?
Right-sided heart disease
-Reduced intrathoracic pressure and physiologic negative pressure ventilation result in an increase in RV preload and reduction in RV afterload
What type of patients would have the biggest benefit from negative pressure ventilation?
Impaired systolic and diastolic RV function
Ex: Older ToF with free PI and dilated/dysfunctional RV
Which patient would show more significant improvement in hemodynamics after extubation, right heart lesion or severe MR?
Right heart lesion…. MR does cause elevated PA pressures and right heart disease, but is overall more a mixed diseased with right and lest heart involvement
How does positive intrathoracic pressure effect LV transmural pressure and LV afterload in left sided heart disease (LV dysfunction, severe MR or AI)?
-Reduces LV transmural pressure
-Reduces LV afterload
What are the first-line agents used in the outpatient management of heart failure?
-ACEi
-B-blocker
Besides an ACEi and B-blocker what other medication should be considered in heart failure patients with poor systolic function?
Antiplatelet drug to prevent intracardiac thrombus formation due to poor systolic ventricular function and increased stagnation of blood
What class would a heart failure patient who has no symptoms and rest and only mild exertional symptoms?
Class II (NYHA)
When would lasix be started to a heart failure management regimen?
If there are symptoms of fluid retention
What are the indications for starting digoxin in the setting of heart failure?
-Symptomatic heart failure despite otherwise optimal medical management
-Atrial fibrillation
True or False: The data is limited on the use of digoxin in pediatric heart failure?
True- usually reserved for use once other medications are initiated and maximized and symptoms persist
True or False: Digoxin has reverse remodeling effects?
False
Digoxin needs to be used with caution in children who have what other problem?
Renal dysfunction
What is a reasonable alternative to an ACEi for outpatient heart failure managmeent?
ARBs
What kind of medication is spironolactone?
Aldosterone-receptor antagonist (mineralocorticoid-receptor antagonist)
True or False: Spironolactone has been shown to reduce mortality and morbidity in adults with heart failure?
True
*Similar peds data limited, but strength of adult evidence has resulted in widespread use of aldosterone receptor antagonists
What are the benefits of aldosterone-receptor antagonists in heart failure?
-Potential to decrease myocardial fibrosis
-Promotes myocardial reverse remodeling
True or False: The current guidelines recommend consideration of aldosterone receptor antagonists for children with chronic systolic heart failure?
True
What are the 2 facets of medical therapy for acute decompensated heart failure based on adult guidlines?
-Symptom management
-Long-term potential for cardiac reverse remodeling
What medications are utilized in the initial management of heart failure?
1st line:
-ACEi
-B-blocker
Consideration as 2nd line agent:
-Aldosterone receptor antagonist
What is most pediatric heart failure management based on?
Adult studies (pediatric data is limited)
What are the most beneficial interventions to improve low cardiac output state in the post-operative period?
-Correct any contributing factors to worsening myocardial function
-Optimize O2 delivery
What is a ventilator strategy to improve acidosis and hypoxemia in a post-op patient with low CO?
Increase minute ventilation
*Patients likely to develop worsening lung compliance and gas exchange because of 3rd spacing of intravascular fluids and pulmonary edema…develop increased venous pressure and tachypnea
What will happen to a patient in pressure control ventilation who develops worsened lung compliance?
-Lower tidal volumes with same pressure leading to tachypnea (due to poor minute ventilation)
*Often tachypnea doesn’t effectively compensate for respiratory acidosis and hypoxemia
What can be done to help a patient in pressure control ventilation who develops worsened lung compliance and resultant acidosis and hypoxemia?
-Increase minute ventilation: Either increase pressure to improve tidal volume or increase RR)
What are some of the factors that impact myocardial contractility?
-Catecholamine state
-Volume status (Frank-Starling mechanism impacting myocardial crossbridges and tension)
-Hypoxemia
-Hypocalcemia
-Other electrolyte abnormalities
-Acidosis
What are the mechanisms by which hypoxemia and acidosis impair contractile function of the myocardium?
-Reduced Ca sensitivity
-Reduced ATP generation
-Direct ischemic injury
The effects of contractile function on the myocardium by acidosis and hypoxemia are more pronounced in what group of patients and why?
-Neonates
-Abnormal handling of Ca by immature sarcoplasmic reticulum (neonatal myocardium is even more sensitive to these factors)
How does a CaCl infusion act in a neonate?
As a potent inotrope
What infusion has the effects of reducing LV afterload, improving distal perfusion and acting as an inotrope?
Milrinone
What is important to remember when initiating a milrinone infusion?
Long half-life, takes time to become effective
What should be considered prior to increasing milrinone infusion in a patients with hypotension?
Milrinone would likely worsen hypotension unless other interventions to improve contractile function are enacted
What should be considered for a patient with a borderline Hgb to improve oxygen delivery?
Transfusion of pRBCs
Why is the neonatal myocardium even more sensitive to hypoxemia, hypocalcemia and acidosis?
Immature SR
What are the recommendations for catheter-based intervention on the aortic valve based on?
Catheter-based measurements of LV and ascending aorta pressures… important to approximate the measurement using echo
What are the class I recommendations for aortic valvuloplasty in children with isolated AS?
-Resting, catheter-based, peak-to-peak gradient of =/> 50mmHg
-Infants with critical AS or decreased systolic function regardless of valve gradient
-Children with a catheter-based, peak-to-peak gradient of 40mmHg with symptoms or ECG changes
What is a potential way to underestimate the velocity of AS by echo?
If the Doppler beam used for interrogation of flow isn’t parallel to the jet… ned the angle of interrogation to be as close to parallel to the jet as possible
What are some imaging windows and strategies to help align the angle of interrogation by echo for AS?
-Apical, high right parasternal and suprasternal views
-Consider PEDOF probe (small dual-crystal continuous-wave Doppler)
If you are measuring AS from the apical view, what do you have to be careful you are not accidentally measuring?
MR velocity
True or False: The physics involved in flow through the stenotic aortic valve creates specific challenges for accurately translating the peak instantaneous Doppler derived indices to the peak-to-peak gradients at cath
True
A peak velocity measured via what type of Doppler if often used to estimate the peak pressure gradient across a stenotic aortic valve?
CW Doppler
How is the peak pressure gradient derived from peak velocity?
Modified Bernoulli equation
Peak pressure gradient = 4v2
*v = peak velocity
What is pressure recovery?
A possible source of discrepancy in echo estimation of a catheter-derived gradient
Why does the pressure recovery phenomenon occur?
Necessity for conservation of energy
Describe pressure recovery
-When blood flow occurs through a region of stenosis, kinetic energy of the flow increases and the potential energy decreases
-At the vena contracta (where flow is measured by CW Doppler using optimal technique) pressure gradient is maximal because pressure is at lowest point
-Downstream from vena contracta, there is decrease in flow velocity and in kinetic energy of flow
-To maintain conservation of energy, pressure increases or “recovers”
-Cath pressure measurements are not made at the vena contracta, but in the downstream region
*Energy is stored as pressure energy proximal to a valve, then converted to kinetic energy as blood flows through a valve and finally converted (or recovered) back into pressure energy distal to the valve
*Max pressure is the pressure difference between the LV and site of lowest pressure as (the vena contracta) measured by CW Doppler
*Net pressure is the difference between the LV and the point distal to the vena contracta where pressure recovery as occurred (measured at cardiac catheterization)
-Sometimes net pressure and maximal pressure are similar, but substantial number of cases the pressure recovery phenomenon causes major discrepancies between the max pressure measured by CW Doppler and net pressure measured by cath (like patients with a small aortic valve annulus and small ascending aorta)
What is different about the timing of measurements pf peak pressure gradients by cath versus echo?
-Pressure difference measured by cath (ex. from LV to Asc Ao) doesn’t occur simultaneously
-Difference in time isn’t measurable by instantaneous velocity measurements via echo
What echo measurement correlates best with a cath peak to peak gradient?
Mean gradient by CW Doppler
What is a minimum peak velocity for severe AS in the setting of normal systolic function?
4M/sec
*Generally correlates to a cath derived gradient of 50mmHg
*A PIG by echo of 50mmhg would correlate to a lower directly measured gradient
True or False: A mean AoV gradient of 40mmHg in the setting of normal systolic function doesn’t meet criteria for intervention?
True
What is important to account for when assessing AS gradients?
LV systolic function
-Decreased LV systolic function will decrease CO which can lead to a falsely low AoV gradient
Peak echocardiographic velocity and pressure gradient measurements tend to overestimate the catheter-derived transvalvular pressure gradient in AS due to what physiologic concept?
Pressure recovery
What echo gradient correlates better with a catheter-derived aortic valve gradient?
Mean
A mean echo gradient of what is the cutoff value for severe AS that requires intervention in the setting of normal systolic function?
50mmHg
A peak velocity of what is the cutoff value for severe AS that requires intervention?
4M/sec
How can congenital LQTS manifest initially in infants?
Bradycardia- pseudo 2:1 block
What patients with congenital LQTS have poor prognosis with with mortality >50% in the first 6 months of life up to 67% by 2 years?
Psuedo 2:1 AV block and TdP
In congenital LQTS manifesting as 2:1 AV block, how would you explain the AV block?
Functional- secondary to markedly prolonged repolarization
*AV conduction normalizes if QTc shortens and heart rate decreases
What are some of the gene mutations that result in congenital LQTS?
-At least 13 genetic forms
-K-channel proteins: KCNQ1, KCNH2
-Na-channel proteins: SCN5A
-Ca-channel related factors
-Membrane adaptor proteins
Patients with LQT1, LQT2 and LQT3 genotype make up what % o patients with genetically confirmed LQTS?
> 92%
LQT1 mutation?
KCNQ1- Loss of function
LQT2 mutation?
KCNH2- Loss of function
LQT3 mutation?
SCN5A- Gain of function
Brugada mutation?
SCN5A- Loss of function
What gene mutation is responsible for the AD form of CPVT?
Gain of function mutation in RYR2
What kind of tachycardia does CPVT cause?
Polymorphic VT (QTc typically normal)
What does a gain of function mutation in KCNQ1 cause?
Short QT syndrome type 2
What gene mutations cause most cases of LQTS?
-Loss of function KCNQ1 (1)
-Loss of function KCNH2 (2)
-Gain of function SCN5A (3)
True or False: Newborns with congenital LQTS manifesting with pseudo 2:1 AV block and TdP have poor prognosis?
True
What can be an early manifestation of congenital LQTS?
Fetal bradycardia
How to Ca channel blockers work?
-Block L-type Ca channels
-Reduce Ca influx and subsequent Ca release from SR
*Some with more prominent peripheral vascular effects
*Some with significant cardiac effects- reduced myocardial contractility and depressing sinus node automaticity and AV node conduction
Which type of CCB acts primarily in vascular smooth muscle and exerts a primary reduction in vascular tone, SVR, and BP?
Dihydropyridine CCB
Which type of CCB is fairly nonselective and exerts its effects in the heart (decreased HR and cardiac contractility) as well as in the vascular system (loss of vascular tone, hypotension)?
Non-dihydropyridine
Is a toxic ingestion of a non-dhydropyridine CCB or dihyrdopyridine CCB more severe (may be fatal in small children with just a single adult dose)?
Non-dihydropyridine (diltiazem or verapamil) CCB is more severe than dihydropyridine (nifedipine or nicardipine)
What are the non-dihydropyridine CCB?
Diltiazem
Verapamil
What are the dihydropyridine CCB?
Nifedipine
Nicardipine
How does non-dihydropyridine CCB toxicity present?
Early onset bradycardia
How does dihydropyridine CCB toxicity present?
-Initial reflex tachycardia due to vasodilatory shock
-Proceeds to bradycardia later in presentation
Does CCB toxicity cause hypoglycemia or hyperglyemia?
Hyperglycemia- L-type Ca channels on islet cells of pancreas that are responsible for insulin release
*Can distinguish CCB toxicity from BB blocker toxicity by hyper/hypoglycemia, respectively
What are some of the signs and symptoms of CCB toxicity?
-Metabolic acidosis
-Endo organ injury
-Complete cardiopulmonary failure
-Bradycardia
-Hyperglycemia
What is important to note in a child that had a toxic ingestion of a CCB?
If it is an extended release formulation
What is involved in the management of a toxic CCB ingestion?
-If symptomatic, prepare to manage HR, BP and metabolic status
-Early in course, can try gastric decontamination (activated charcoal)
-ABCs
-Ca supplementation
-Correct acidosis
-Manage electrolytes
-Insulin/dextrose for hyperglycemia
-Vasoactives to increase vascular tone
-Inotropes to improve cardiac contractility
-HR control with atropine or external pacing
-Lipid emulsion to bind active CCB in blood stream (CCB highly lipophilic)
-ECMO
What should you consider in a patient who is bradycardic, hypotensive and hyperglycemia who is in shock with metabolic acidosis after ingesting grandma’s medications?
Non-dihydropyridine CCB toxicity
*If dihydropyridine CCB (nicardipine), may have had hypotension with reflex tachycardia initially
Ingestion resulting in bradycardia, hypotension and hypoglycemia?
B-blocker
What is the major toxicity associated with metformin?
Lactic acidosis
How does metformin toxicity present?
-GI complaints- nausea, vomiting, abdominal pain, diarrhea
-Altered mental status
-Tachypnea (in setting of severe lactic acidosis)
-Hypotension
-Tachycardia
True or False: Hypoglycemia is common in metformin ingestion?
False
True or False: CCB (especially non-dihydropyridines like diltiazem and verapamil) can be lethal in children, with as little as a single adult dose?
True
What are some of the signs and symptoms of CCB toxicity?
-Hypotension
-Heart block
-Bradycardia
-Lethargy
-Hyperglycemia
-Metabolic acidosis
-Organ failure
-Complete CV collapse
How is CCB toxicity managed?
-Depends on timing and severity of exposure
-Detoxification
-Ca infusion
-Insulin/glucose
-Correction of metabolic abnormalities
-Vasoactive medications
-Lipid emulsion
-ECMO
What is one of the possible surgical approaches to cc-TGA?
Double switch- Senning atrial switch plus arterial switch
*Goal of to reroute blood flow the MV and morphologic LV become the systemic AV valve and vantricle
What are some clues to cc-TGA to echo?
-Reverse off-setting of the AV valves
-Septophobic right sided valve (mitral valve)
-Right-sided ventricle is smooth walled
-Septophilic left sided AV valve (tricuspid valve)
*Also consider if the patient has a pacemaker or hear block
What is the position of the interventricular septum in cc-TGA?
Sagittal
What are the paths of venous return to the morphologic LV and morphologic RV after atrial switch?
-Pulmonary venous baffle (venous return to morphologic LV)
-Systemic venous baffle (venous return to morphologic RV)
In the arterial switch operation, what is the position of the pulmonary artery bifurcation?
-Anterior to the aorta (LeCompte maneuver)
Complete heart block is estimated to affect what % of cc-TGA patients per year (even without surgery)/
2%
What is the incidence of surgically acquired heart block in cc-TGA?
20%
What is surgically acquired heart block often related to in cc-TGA?
-Resection of LVOT
-VSD closure
*When these commonly associated lesions are present in cc-TGA
What % of cc-TGA patients have associated VSDs?
80%
What % of cc-TGA patients have some form of LVOTO?
30-50%
cc-TGA patients with that 2 things should be considered for anatomical repairs (double switch) in the first few years of life?
-TR
-RV dysfunction
What is a form of anatomical correction for cc-TGA and restores the mitral valve and left ventricle to the systemic side of the circulation?
Double switch
True or False: Cardiac causes of pediatric chest pain are rare?
True
True or False: Normal history and physical exam findings are sufficient in most cases to categorize chest pain in pediatrics as non-cardiac in origin?
True
When is an echo appropriate in the workup of chest pain?
-Exertional chest pain (try to differentiation between degrees of exertion- pain at high levels of exertion is more concerning for ischemic pain and warrants echo, pain at low levels may not)
-Abnormal ECG
-1st degree relatives with unexplained sudden death or cardiomyopathy
True or False: Incomplete right bundle branch block and early repolarization are considered normal variants on ECG?
True
Besides exertional chest pain, abnormal ECG and 1st degree relative with unexplained sudden death or cardiomyopathy, what are some other times where echo may be appropriate in the workup of chest pain?
-Chest pain + other signs/symptoms of CV disease
-Chest pain with FHx of premature CAD
-Chest pain after recent onset fever (pericarditis, myocarditis, etc.)
-Chest pain after recent illicit drug use
When is echo rarely appropriate in the workup of chest pain?
-No other signs or symptoms of CV disease
-Benign family history (+FHx applies to 1st degree relatives only)
-Normal ECG or no recent ECG done
-Pain is non-exertional
-Reproducible pain with palpation (costochondritis) or deep inspiration
ECG with sinus bradycardia, 1st degree AV block, marked QRS prolongation, prolonged QTc?
Flecainide toxicity
What should always be considered in the differential diagnosis of a patient presenting with bradycardia and prolongation of the QRS, PR and QT intervals?
Flecainide toxicity
True or False: Flecainide toxicity is potentially fatal?
True
What do you need to counsel parents on regarding giving flecainide at home?
Shake the bottle well before every dose administration- active compound may settle at bottom of a constituted liquid formulation- medication may be much more concentrated in last few doses of the bottle
Consumption of what can reduce flecainide levels?
Milk or milk-based formula
*Families need to adhere to a set timing of milk drinking with respect to flecainide administration
If a child has a decrease in the consumption of milk, what may be needed for the flecainide dose?
Decrease in dose
What type of antiarrhythmic is fleciainide?
Class 1C
How does flecainide work?
Potent cardiac, fast, inward Na channel blocker
What are the effects of flecainide on the PR, QRS and QT intervals?
Increased duration
*QT interval prolongation mostly due to QRS widening
What is an effective 2nd tier antiarrhythmic agent commonly used to treat arrhythmias when 1st line agents like B-blockers have failed?
Flecainide
Flecainide can be proarrhythmic under what 3 circumstances?
-High doses
-Patients with CAD
-Patients with structural heart disease
What are the effects of flecainide on atrial flutter and atrial fibrillation?
-Slow atrial flutter (facilitates 1:1 AV conduction)
-Can convert fibrillation into flutter and cause monomorphic and polymorphic ventricular tachycardia
What is the cause of death in cases of flecainide toxicity?
-Rapid-onset hypotension and ventricular dysrhythmias
*Conduction disturbances can progress rapidly to life-threatening dysrhythmias
How is flecainide toxicity diagnosed?
-ECG changes (serum flecainide levels can take days to result)
What are the 2 key initial management strategies in flecainide toxicity?
-Na: Hypertonic NaBicarb, NS boluses ad B-sympathomimetic agents to counter bradycardia and hypotension
-Avoid any electrolyte imbalances (hypokalemia)
In flecainide toxicity, what may be needed for hypotension refractory to NS boluses?
Vasopressin
In flecainide toxicity what may be needed to TdP?
-Mg
-Ventricular pacing
In flecainide toxicity what may be attempted for refractory arrhythmias?
Cardioversion
What are 2 potential options for refractory cases of flecainide toxicity?
-IV lipid therapy (bind flecainide)
-ECMO
True or False: Flecainide is not dialyzable?
True
What are some of the ECG changes seen with hypokalemia?
-PR interval prolongation
-ST depression
-T-wave inversion
-U waves
In a patient taking flecainide, what ECG changes should make you suspect toxicity?
-Bradycardia
-Prolongation of QRS, PR and QT interval
-Wide complex tachycardia
What are 2 potential initial steps in the management of flecainide toxicity?
-NA as hypertonic NaBicarb
-IV lipid
What needs to be done before each dose of liquid flecainide?
Shake it
When do ductal-dependent right sided obstructive lesions usually present?
1st week of life after ductus arteriosus closes
What happens after the duct closes in a ductal dependent right-sided obstructive lesion?
-Marked reduction in pulmonary blood flow
-Signs/symptoms of cyanosis and respiratory distress
What is the standard of case to assess the right side of the heart and coronary arteries in PA-IVS?
Cath- high % of patients with PA-IVS have high-risk circulation secondary to coronary arterial abnormalities
-RV angiogram is important to assess RV morphology and for presence of coronary artery fistulae
If there are RV-coronary artery fistulae in PA-IVS, what needs done during cath?
-Selective injection of coronary artery origins from aorta
-Important to rule out proximal coronary artery atresia, interruption or coronary artery stenosis
Describe the pathophysiology of RV-coronary artery fistula in PA-IVS
-Aortic diastolic pressure may be inadequate to promote coronary blood flow when obstructive lesions are present
-Coronary flow through a hypertensive RV that occurs in systole through the RV-coronary fistulae may be necessary to provide adequate myocardial tissue delivery
Why is it critically imporant to determine whether there is RV-dependent coronary circulation in PA-IVS?
-Decompression of the RV with subsequent reduction in the RVSP may lead to coronary artery ischemia, infarction, cardiac arrest and death
What would be a clue to coronary artery abnormalities in PA-IVS on ECG?
T-wave inversions on ECG
What are the 2 main reasons that cardiac catheterization remains the standard of care in PA-IVS?
-Define cardiac anatomy (RV morphology, presence of RV fistulae and coronary artery anatomy
-Therapeutic benefit (PDA stenting in cases of RV-dependent coronary circulation or RF perforation of the PV with balloon pulmonary valvuloplasty is coronaries aren’t RV dependent)
Besides cath, what else can be helpful to define coronary anatomy in PA-IVS?
CTA with coronary angiography (can possibly see coronary stenosis, atresia or interruption)
True or False: Patients without RV-dependent coronary circulation and a tripartite RV may be candidates for catheter-based interventions to open the PV and RVOT to allow the right heart to decompress, remodel and grow over time
True
True or False: BAS is rarely required in PA-IVS because there is an obligatory R-L atrial shunt that results in persistent patency of an atrial communication?
True- This very rarely becomes restrictive
What is part of the initial workup in PA-IVS to delineate coronary anatomy (RV dependence)?
Cath
An infant with PA-IVS and RV dependent coronary circulation could have what 2 potential first interventions?
-BTT
-PDA stent
*RV shouldn’t be decompressed in the setting of an RV-dependent coronary circulation
PA-IVS has an association with what coronary problems?
-RV to coronary artery fistulae
-RV dependent coronary artery circulation
What is important in PA-IVS to determine whether there is an RV-dependent coronary circulation?
Cath- will impact clinical management and surgical/interventional decision making
What are some of the initial management options for PA-IVS?
-RF perforation of PV +/- PDA stenting
-Surgical intervention (BTT)
PVCs with a left bundle morphology and an inferior axis (positive in II, III and aVF) are coming from where?
Outflow tract (most commonly RVOT, but can be coronary cusps too)
True or False: Outflow tract PVCs tend to have a benign course in patients with a structurally normal heart and no concerning family history?
True
True or False: Outflow tract PVCs may have spontaneous remission over time or decrease in severity?
True- Rare to see a significant increase in the frequency of ectopy over time
What is included in the evaluation of children with frequent ventricular ectopy?
-Detailed FHx
-ECG
-Echo
-Holter monitor
*Consider exercise stress test for v-tach or multiform PVCs
*Consider CMR with concern for underlying cardiomyopathy, concerning family history for arrhythmogenic cardiomyopathy or concerns for acute cause of arrhythmia (myocarditis)
Patients with > _% ectopy on Holter monitors are at risk for developing ventricular dysfunction and should have follow-up echo done?
10
Treatment for patients with frequent outflow tract PVCs is usually reserved for which patients?
-Symptomatic
-Develop ventricular dysfunction
-Sustained ventricular tachycardia
What is the first line treatment for patients with frequent outflow tract PVCs?
-B-blockers
*Can consider ablation
What medication is helpful in patients with Belhassen tachycardia?
Verapamil (CCB)
Where does verapamil-sensitive tachycardia originate from?
LV (most commonly from posterior fascicle)
Describe verapamil-sensitive ventricular tachycardia?
-RBBB morphology
-Superior axis (negative in II, III and aVF)
Describe outflow tract PVCs?
LBBB morphology and inferior axis (+ in II, III and aVF)
True or False: Outflow tract PVCs tend to have a benign course?
True
Ventricular dysfunction can be seen in patients with PVCs that account for >_% of their total beats on Holter monitoring?
10%
Initial evaluation for ventricular ectopy, AIVR or ventricular tachycardia?
-ECG
-Echo
-Holter
-FHx
Follow-up evaluation for persistent isolated ventricular ectopy?
-Follow-up Holter
-Consider echo
Follow-up evaluation for ventricular tachycardia?
-Consider exercise, MRI, SAECG
-Rule out acute causes
Follow-up evaluation for multiform ventricular ectopy or polymorphic ventricular tachycardia?
-Rule out acute causes
-Exercise test when stable
-Consider MRI
Management of ventricular ectopy, AIVR or ventricular tachycardia if normal function and asymptomatic?
Observation
Management of ventricular ectopy, AIVR or ventricular tachycardia if symptomatic?
-Consider ablation v. BB for ectopy or OFT VT
-Consider BB for infants with intrafascicular verapamil sensitive reentrant tachycardia
-CCB v. ablation for children with intrafascicular verapamil sensitive reentrant tachycardia
Management of ventricular ectopy, AIVR or ventricular tachycardia if ventricular dysfunction or hemodynamic compromise?
-CCB v. ablation for children with intrafascicular verapamil sensitive reentrant tachycardia
-Medication v. ablation for ectopy or OFTVT
Management of ventricular ectopy, AIVR or ventricular tachycardia if polymorphic ventricular tachycardia?
Correct treatable causes, PALS
What is a good tool to use in post-operative rhythm monitoring?
Atrial wire recordings
True or False: Open chest, chest wall edema, chest tubes and dressings can make it difficult to perform a good quality ECG?
True
Why can JET be challenging to diagnose post-operatively?
P-waves may not be discernible because simultaneous ventricular depolarization and QRS complexes mask atrial depolarization
True or False: Temporary atrial pacing wires can be very useful post-op for diagnostic and therapeutic pruposes?
True
How is atrial depolarization recorded if you connect the right arm ECG lead to the exposed distal end of one of the temporary atrial pacing wires?
-Sharp high-frequency unipolar signal on the ECG lead I (atrial pacing wire to LA) and lead II (atrial pacing wire to LL)
*Lead III (LA to LL) isn’t affected because it doesn’t capture the amplified signal from the atrial pacing wire
What happens if you connect one temporary atrial pacing wire to the right arm ECG lead and the other to the left arm ECG lead?
-Get bipolar atrial depolarization on lead I
-Unipolar atrial depolarization on leads II and III
Flutter waves are easier to see in what circumstance?
When there is a higher degree of AV block
Over drive pacing at what rate and for how long is a safe and effective method to terminate flutter?
110-130%, 20-30 seconds
*Pacing rate can be sequentially increased and duration altered if initial rate doesn’t interrupt flutter
HR in flutter is determined by what?
AV conduction
What is AV conduction in flutter?
Often 2:1 (HR is half the flutter rate)
When you overdrive pace the heart for flutter, what rate do you choose?
110-130% above the flutter rate (not the HR)
How would amiodarone effect flutter?
Could slow AV conduction and decrease HR, but unlikely to terminate flutter
How does adenosine effect flutter?
Cause AV block and unmask the flutter waves, but unlikely to terminate the flutter
True or False: Synchronized cardioversion can be used to terminate flutter?
True
In a normal limb lead ECG where does lead I go?
RA-LA
In a normal limb lead ECG where does lead II go?
RA-LL
In a normal limb lead ECG where does lead III go?
LA-LL
Describe where the leads go if you connect the RA ECG lead to a temporary atrial pacing wire (atrial depolarization recorded as a sharp unipolar high-frequency amplified signal)?
I: TAPW to LA
II: TAPWW to LL
III: LA-LL… not affected, doesn’t capture amplified signal from the TAPW (remains unchanged)
How can you get a bipolar atrial depolarization recorded on lead I and unipolar on lead II/III?
Connect 1 TAPW to RA and second TAPW to LA
What is flutter rate determined by?
Frequency of flutter waves… 60,000/flutter wave interval in msec
What is the most common form of syndromic obesity?
Prader-Willi
What is caused by the absence of expression of paternally active genes on the long arm of chromosome 15?
Prader-Willi
How can Prader Willi lead to pulmonary hypertension?
-Chronic hypoxia from OSA
*PW associated with sleep disordered breathing in 70% of cases (OSA or central)
*Leads to chronic hypoxia which can cause pulmonary hypertension
What is characterized by episodes of hypopnea and apnea associated with hypoxia and hypercapnia during sleep?
OSA
What is a very important complication of OSA?
Pulmonary HTN
*OSA associated with pulmonary HTN in about 20% of adults with OSA… usually mild unless there is coexistent obesity hypoventilation syndrome
How does OSA cause pulmonary hypertension?
Intermittent hypoxic pulmonary vasoconstriction which can lead to vascular remodeling
What is the primary etiology for pulmonary hypertension in patients with sleep disordered breathing?
-Alveolar hypoxia and resulting pulmonary vasoconstriction
*Can also have increased LV wall thickness and decreased diastolic function which can contribute
What are systemic BP variability and systemic HTN associated with?
Sleep disordered breathing
What changes in HR are associated with OSA?
-Increased HR variability
-Elevated mean HR
*Even during waking hours
True or False: OSA can be associated with more significant arrhythmias like NSVT, 2nd degree AV block and sinus arrest
True
What are some of the hemodynamic consequences associated with OSA?
-Increased HR variability
-Systemic HTN
-LVH
-Pulmonary HTN
What can worsen pulmonary HTN present in patients with OSA?
Worsening hypoxia due to an infection or some other cause
What type of physiology would a patients with MA and DORV with small PFO develop in infancy?
-Pulmonary overcirculation
-LA HTN
In DORV with no outflow obstruction to either great artery, what will happen in the first few weeks of life?
Pulmonary overcirculation… mixed blood in the RV will preferentially flow into pulmonary vasculature as PVR falls
How does increased Qp:Qs present?
-Tachypnea
-Elevated SpO2
-Increased pulmonary vascularity
-Congestion on CXR
-Reduced systemic blood flow
What are some options for medical management with pulmonary overcirculation?
-Diuretics
-Nutritional support
- +/- Non-invasive or invasive PPV
-Afterload reduction
What is the goal of the first stage of SV palliation?
-Unobstructed systemic cardiac output
-Adequate but controlled pulmonary blood flow
-Unobstructed pulmonary venous return to the heart
What should be the first intervention for a patient with MA/DORV, no pulmonary stenosis and a restrictive PFO?
BAS or atrial septectomy + PA band
When is a PA band indicated in single ventricle heart disease
When native obstruction to pulmonary flow is absent or inadequate to prevent PAH and CHD
*Reduces pulmonary arterial blood volume and pressure
Does PGE need to be initiated in a 26 week 650g infant with CoA and a large PDA?
Not necessarily, PDA unlikely to close on its own and can be monitored for very closely
What are options for ductal closure in micro-preemies?
-Medical
-Surgical ligation
-Cath based (Piccolo)
What are current contraindications to transcatheter occlusion of a PDA?
-Younger than 3 days
-Weight <700g
-CoA
-LPA stenosis
-Ductal dependent CHD
-Active infection
-Intracardiac thrombus
What characteristics of a PDA in small neonates are transcatheter occlusion devices not suited well for?
-Short (<3mm)
-Large
What is a contraindication to PDA closure?
CoA
(Ductal dependent pulmonary or systemic blood flow)
Describe P2 in pulmonary valve stenosis
Quieter- Due to limited excursion of the PV
What happens to S2 in pulmonary valve stenosis?
Becomes widely split with a harsh systolic murmur loudest at LUSB with an ejection click
What causes the widely split S2 in pulmonary valve stenosis?
Delay in pulmonary valve closure which worsens as the severity of obstruction worsens
What is the recommended primary treatment for valvar PS?
Balloon valvuloplasty
Which types of patients have low success rates with balloon valvuloplasty of the pulmonary valve?
Those with dysplastic and significantly thickened valves (like in genetic disorders like Noonan)
*Often still attempted in this group however
What are the class I AHA cath-based recommendations for pulmonary valvuloplasty?
-Critical PS (PS present at birth with cyanosis and evidence ductal dependence)
-Valvar PS with peak to peak cath gradient or echo peak instantaneous gradient of >40mmHg or significant valvar stenosis with RV systolic dysfunction
*Not uncommon to follow patients until the echo PIG increases above 40mmHg (PIG can go up to 60-70 even) in an asymptomatic patient prior to referral
Echo derived PIG correlate with cath peak-to-peak gradients for what?
PS
*Echo may slightly overestimate peak to peak gradients in the cath lab
Flattening of the IVS in systole is consistent with RVSP that is at least what?
Greater than half systemic
True or False: Few patients require pulmonary valve replacement after a catheter based intervention on the pulmonary valve?
True
Patients with what characteristic are likely to have more pulmonary insufficiency at follow-up?
Lower BSA at time of intervention
True or False: The prognosis in an otherwise health infant with isolated PS is exellent?
True
What is the gold standard for treatment of isolated PS?
Catheter-based intervention
True or False: Mild degrees of PS in infants and young children may improve over time without intervention?
True
In what time frame is PS most likely to either progress or regress?
In the first 2 years of life
*Can just watch mild PS in an infant
True or False: Catheter based intervention for PS is an effective treatment with favorable outcomes and few long-term adverse effects>
True
In what time frame is mild PS likely to progress or regress?
Within first 2 years of life… need close follow-up during this period
What is the typical response of the conduction over the AV node with administration of adenosine?
Progressive prolongation of the PR/AH interval followed by AV block
During an EP study, progressive prolongation of the PR/AH interval followed by AV block is consistent with the successful ablation of what?
WPW- No residual antegrade conduction over the AP is seen after the ablation
During a WPW ablation, if there is any residual antegrade conduction over the AP, what is seen after giving adenosine?
AV conduction once adenosine blocked the AV node via AP (would see a fully preexcited QRS complex)
What can be helpful in diagnosing WPW syndrome when there is subtle preexcitation and the ECG findings are questionable at baseline?
Adenosine
*Adenosine can block the AP in some patients with WPW syndrome
What would be seen with an adenosine sensitive accessory pathway if you give adenosine (to distinguish it from a successfully ablated AP)?
-PR interval stays constant before blocking
-Successful ablation has prolongation of the PR interval before AV block
True or False: When blocked by adenosine, AP’s aren’t generally capable of rapid antegrade conduction?
True
Ablation of what type of AP carries an increased risk of AV block given the proximity to the AV node and His bundle?
Para-Hisian AP
*Don’t want to be more aggressive and deliver additional lesions when there isn’t any inducible SVT or suggestion of residual AP antegrade conduction with adenosine
Why is it not uncommon to have RBBB after ablation of para-Hisian AP’s?
To avoid damage to the AV node and His bundle, a more distal or ventricular lesion is placed
What is the effect of adenosine administration in WPW?
Increases pre-excitation by blocking the AV node
What can be helpful in diagnosing WPW when there is subtle preexcitation and te ECG findings are questionable at baseline?
Adenosine
True or False: Adenosine can rarely block the AP in WPW?
True
True or False: Accessory pathways that are blocked by adenosine are generally not capable of rapid antegrade conduction?
True
What happens if you do atrial pacing in someone with an AP after you give adenosine?
Antegrade AV conduction over the AP only which results in a fully pre=excited QRS (the AV node is blocked by adenosine)
What happens is you do atrial pacing in someone with an AP after you have ablated it successfully and give adenosine?
No AV conduction because AP is ablated and AV node is blocked by adenosine
What is characterized by a single arterial vessel giving origin to the coronary, systemic and pulmonary arteries?
Truncus arteriosus
Describe the associated VSD with Truncus Arteriosus?
Large
Located within outlet muscular septum
What is a multipotent population of cells that arise from the neural tube during embryonic development?
Neural crest cells
What are the cardiac neural crest cells?
A subpopulation of the neural crest cells which migrate into the developing heart
When are the cardiac neural crest cells added to the heart?
After the formation of the primitive heart tube- referred to as the secondary heart field
What acts as a scaffold for the cardiac neural crest cells to migrate to the 3rd, 4th and 6th pairs of pharyngeal arches and then into the heart?
Primitive heart tube
What do the cardiac neural crest cells do upon arrival to different locations in the heart?
Differentiate into mesenchymal and smooth muscle cells
What do the cardiac neural crest cells within the heart faciltiate?
-Outflow tract septation
-Semilunar valve formation
-Formation of separate walls within the intrapericardial arterial trunks
What do the cardiac neural crest cells within the pharyngeal arches help facilitate?
Normal aortic arch and branch pulmonary artery development
What explains the failure of septation into the ascending aorta and PA, single semilunar valve and lack of outflow tract septation present in truncus arteriosus?
Absence of cardiac neural crest cell migration into the developing heart
What can be explained by abnormalities in cardiac neural crest cell migration?
Spectrum of aortic arch anomalies seen with conotruncal defects
What is a factor in the morphogenesis of TGA?
Absence of the normal subpulmonary infundibulum with failure of subaortic infundibulum to resorb
What results in cc-TGA?
Looping of the primitive heart tube to the left and not the right as in the normal heart
What results from a failure of the endocardial cushions to fuse?
AVSD (defect of the atrioventricular septum and AV valve abnormalities)
What cells are added to the heart after the formation of the primitive heart tube and are called the secondary heart field?
Cardiac neural crest cells
What cells facilitate outflow tract septation, semilunar valve formation and formation of separate walls within the intrapericardial arterial trunks?
Cardiac neural crest cells
What results from abnormalities of cardiac neural crest cell migration into the developing heart?
Conotruncal defects
What does a ventricular pressure-volume loop plot?
Changes in ventricular pressure (y-axis) and volume (x-axis) that occur during the cardiac cycle
The shape of a ventricular pressure-volume loop changes in response to what?
Changes in preload, afterload and inotropy
*These variables are interdependent, but curves can be helpful to understand the independent effects of each variable when others held constant
What happens to stroke volume in a higher afterload state?
It is smaller- less volume is ejected because the aortic valve is closing at a higher pressure
What is the effect of decreasing afterload by lowering BP with something like sodium nitroprusside) on stroke volume?
Higher stroke volume at same preload and contractility
Increases in stroke volume with afterload reduction are more pronounced in what situation?
When baseline inotropic state is reduced like in post-CPB or heart failure
Increasing epinephrine increases …
Myocardial contractiltiy
In the pressure-volume loop, what is represented by the end-systolic pressure volume relationship?
Contractility
As contractility changes, the slope of what line on the pressure-volume loop changes?
End systolic pressure volume relationship
How does vasopressin effect BP?
Raises is (potent vasoconstrictor)
Esmolol is used predominantly for what?
Negative chronotropic effects (selective B1 antagonist)
At constant preload and inotropy, reducing afterload does what to SV?
Increase
Conduit injury during a transcatheter PVR has been reported in up to what % of procedures?
20%
What is conduit injury during a transcatheter PVR most commonly associated with?
Preparation of the conduit for valve placement (either with balloon angioplasty or stenting of the conduit)
What is a category 0 conduit tear?
No injury or conduit wall injury: no contrast seen extending outside of, or extravasating (leaking) outside of, the longitudinal plane of the vascular lumen
What is a category 1 conduit tear?
Contained injury: small collection of contrast seen extending outside of the longitudinal plane of the vascular lumen less than or equal to half the diameter of the adjacent conduit, indicating the occurrence of an aneurysm, pseudoaneurysm or well-contained injury. This category can also be used to describe the unlikely occurrence of a dissection with contrast held in a contained space within the conduit lumen
What is a category 2 conduit tear?
Partially contained injury: large collection of contrast seen outside the wall of the RV-PA conduit greater than half the diameter of the adjacent conduit
What is a category 3 conduit tear?
Uncontained conduit injury: extravasation of contrast into the mediastinum or pleural cavity
How are most conduit injuries treated?
Placement of a covered stent
*But surgical backup should be available
What is an inherited disorder resulting from mutations in the FBN1 gene?
Marfan syndrome
What systems does Marfan predominantly affect?
CV
Skeletal
Ocular
When do most patients with classic Marfan syndrome present?
Late childhood or adolescence
True or False: There is a severe subtype of Marfan syndrome with rapidly progressive disease that is seen in the neonatal period or infancy
True
What does early onset Marfan (neonatal or infantile Marfan) occur due to?
Mutations in the “hotspot” regino of the FBN1 gene between exons 24 and 32
What is the inheritance of neonatal or infantile Marfan?
Often sporadic with no family history of similar manifestations
What are the features of neonatal or infantile Marfan?
-Dolichostenomelia (long limbs relative to trunk length)
-Dolichocephaly
-Deep-set eyes
-Senile facies due to loose skin folds
-High arched palate
-Micrognathia/retrognathia
-Arachnodactyly
-Chest wall dermoities
-Scoliosis
-Joint contractures
-Ocular manifestations
True or False: In early-onset Marfan, the CV and skeletal manifestations are severe and progress rapidly?
True
What is the most common cardiac manifestation (70-100% of cases) in early-onset Marfan?
MVP with varying degrees of MR
What is the cardiac presentation in early-onset Marfan?
Severe MR causing heart failure in infancy/early childhood that is often refractory to medical therapy
What is the management of the severe MR seen in early-onset Marfan?
-Surgical repair of AV valves is difficult due to severe myxomatous changes in the valve leaflets and chordae
-Consider MV replacement (despite associated high risk of mortality and morbidity)
Besides severe MR, what are the other CV manifestations seen in early-onset Marfan?
-TR
-Progressive dilation of the Ao root
What is given in early-onset Marfan to help reduce the rate of aortic root dilation?
-B-blockers
-ARBs
What is the prognosis of early-onset Marfan?
Poor- most infants die by 2 years due to heart failure from severe MR
True or False: Aortic dissection is the most common cause of mortality in infantile-onset Marfan?
False- Heart failure from severe MR (aortic dissection most common cause of mortality in classic Marfan)
Supravalvar AS?
Williams (7q11.23 deletion)
What is early-onset Marfan syndrome?
Rare, rapidly progressive subtype of Marfan syndrome with classic facial features and severe CV, skeletal and ocular manifestations
What are the cardiovascular manifestations of early-onset Marfan syndrome?
-Mitral and tricuspid regurgitation that necessitates valve repair/replacement in early childhood
-Aortic root dilation occurs in most, but dissection is rare
What is the prognosis of early-onset Marfan?
Poor- average life expectancy of less than 2 years
What is mortality in early-onset Marfan usually due to?
Heart failure from severe MR
What are the current guidelines for universal lipid screening?
Between 9-11 and again between 17-21 for children without premature cardiovascular disease risk factors
What is universal screening intended to improve?
The identification and treatment of genetic dyslipidemias like familial hypercholesterolemia
What is the prevalence of heterozygous familial hypercholesterolemia?
1 in 250
How are the select populations at increased risk for premature CVD requiring early and more frequent lipid screening subdivided?
3 groups:
High risk
Moderate risk
At risk
*Management considerations and treatment targets vary based on the risk category
Patients with a history of CoA fall within what risk category for premature CVD requiring earlier/more frequent lipid screening?
Moderate risk
*Patients who were older at time of repair or who have persistent HTN are predisposed to early CV events
True or False: Lipid screening can be performed with a full fasting lipid profile or with nonfasting lipid levels?
True
What is non-high-density lipoprotein cholesterol (non-HDL-C)?
The difference between directly measured total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C)
Non-HDL-C includes what?
All cholesterol present in lipoprotein particles that are considered atherogenic
The 2019 AHA statement for risk-reduction in high-risk patients suggests what for lipid screening?
-Yearly screening with a non-fasting non-HDL
-If TC >200, HDL <45 or non-HDL >145, get a follow-up fasting sample
-If LDL-C is abnormal, a diagnostic evaluation is warranted along with therapeutic lifestyle change and statin therapy based on risk category
What are high risk patients with regards to lipid screening?
-Kawasaki disease with persistent coronary aneurysms
-Heart transplant recipients with coronary vasculopathy
What is the LDL threshold for starting therapy in the high risk patients (Kawasaki with persistent coronary aneurysms and transplant with coronary vasculopathy)?
> 130
What is the LDL threshold to start therapy in moderate-risk patients?
> 160
True or False: For at risk or moderate risk groups, patients may be given a 3-6 month window to lower cholesterol levels with lifestyle changes?
True- but if LDL remains above goal, statin therapy should be added
What is the initial age range for universal lipid screening in patients without CVD risk factors?
9-11
True or False: Pediatric patients with risk factors for premature CVD, including those with specific forms of CHD, should undergo screening for dyslipidemia at younger ages and at close intervals than their peers without risk factors?
True
A nonfasting non-high-density lipoprotein cholesterol level > what is considered abnormal?
145
*Sensitive screening test for dyslipidemia
What are some findings on echo that support a minimal hemodynamic burden from a VSD?
-Effective size being small
-Small size of VSD color Doppler jet
-Restrictive high velocity L-R shunting across VSD on spectral Doppler (high peak pressure gradient indicates that the RVSP and PVR remain low)
-Normal LA/LV size
Describe how aortic valve prolapse can occur in patients with restrictive VSDs
-Occurs secondary to high-velocity shunting across the defect
-Creates a zone of low pressure (Venturi effect)
-Impacts the adjacent cusp of the AoV (usually the right coronary cusp) by pulling the cusp into the defect and disrupting the AoV
-Results in varying degrees of AR
The risk of AR from AoV prolapse in the setting of a VSD increases and peaks when?
Increases during childhood
Peaks between 5-10 years of age
What should be done for AoV prolapse in the setting of a VSD?
-Surgical repair of the VSD
-Removes the low pressure region causing the prolapse and can help prevent or limit progression of ongoing AoV cusp damage and prevent worsening AR
AoV prolapse is seen in what type of VSDs?
-Doubly committed juxta-arterial
-Perimembranous
How often should patients with AoV prolapse undergo surveillance?
Every 6 months to 1 year
When is surgical repair indicated in a small VSD that is hemodynamically insignificant?
If there is AoV prolapse with the development of AR
*Avoid progressive damage to the AoV and worsening AR which can occur if left unrepaired (even with a small VSD)
When is interventional device closure of a VSD recommended per AHA/ACC?
Muscular VSD and only if the VSD is remote from the tricuspid valve and aorta and associated with severe left-sided heart dilation (Class IIb recommendation)
True or False: Even in cases of small pressure restrictive VSDs, surgical repair is indicated in cases of AoV prolapse in the presence of AR to avoid progressive damage to the AoV and worsening AR?
True
What types of VSDs are associated with AoV prolapse?
Perimembranous
Double committed juxta-arterial
What needs to be monitored in patients with small perimembranous and double committed juxta-arterial VSDs?
Echos to assess for AoV prolapse and AR.. require close follow-up with echo surveillance
What is responsible for nearly 40% of complete heart block in the newborn period?
Maternal antibodies (SSA/SSB)- Isoimmune CHB
How do maternal SSA/SSB antibodies cause complete heart block?
Transplacental transmission of the maternal antibodies causes damage to the fetal AV node
Unlike complete heart block that results from a congenital malformation of the conduction system, an immune-mediated block may benefit from early in utero treatment with what?
-Fluorinated steroids
-IVIG
-Both
True or False: Once complete heart block in utero is established, no therapies are known to reverse it?
True
True or False: 70-80% of Mom’s with SSA/SSB antibodies resulting in fetal complete heart block are clinically asymptomatic without a clinical diagnosis of an autoimmune disease (SLE or Sjogren)
True
What should be assessed for when congenital complete heart block is present?
Asses Mom for the presence of SSA/Ro and SSB/La antibodies (irrespective of a clinical suspicion of an autoimmune disorder)
*Helpful in determining the long-term prognosis of current infant, but also in determining the risk of cardiac conduction issues or complete heart block in future pregnancies
For a Mom with SSA/SSB antibodies, what is the first of fetal complete heart block in the first pregnancy and 2nd pregnancy?
-1st is 2%
-2nd is 20% in antibody + Mom’s if the first infant had complete heart block
What medication is currently being studied to decrease the risk of complete heart block in subsequent pregnancies complicated by immune mediated complete heart block in the previous pregnancy?
Hydroxychloroquine
-PATCH trial- Preventive approach to congenital heart block with hydroxychloroquine
There is a 5-30% risk of development of what in patients with immune-mediated congenital complete heart block?
Dilated cardimyopathy
True or False: Most patients with complete heart block need a pacemaker by their adolescent years even if completely asymptomatic?
True
What are the indications for pacemaker implantation in the newborn period for complete heart block?
-Slow escape rate (<50bpm in absence of CHD and <60-70bpm in presence of CHD)
-Symptoms of low CO
-Prolonged abrupt pauses
-Complex ventricular ectopy
-Wide QRS complex escape rhythm
-LV dysfunction
What types of CHD are seen in 50-55% of fetuses with complete heart block?
Complex:
-L-TGA
-Heterotaxy (polysplenia with LA isomerism and interrupted IVC)
What is the heart rate threshold for implanting a pacemaker in newborns with complete heart block in the presence of structural heart defects (L-TGA, Heterotaxy, etc)?
<70bpm
What can be seen in a newborn with congenital long QT syndrome?
2:1 AV block secondary to a markedly prolonged QT interval
True or False: Newborns with congenital long QT syndrome manifesting with 2:1 AV block in utero or during the neonatal period have a poor prognosis?
True- Reported mortality >50% in first 6 months after birth and up to 67% by 2 years of age
What is part of the treatment for neonates with long QT syndrome and 2:1 AV block?
-Epicardial ICD o pacemaker
-B-blockers
-Na channel blockers
True or False: Asymptomatic newborns with immune-mediated congenital heart block, preserved ventricular function, and a HR >55bpm generally don’t require pacemaker implant until adolescent years?
True
What are in the indications for pacemaker implantation in the newborn period for complete heart block?
-Slower escape rate (<50bpm in absence of CHD or <60-70bpm in presence of CHD)
-Any symptoms of low CO
-Prolonged abrupt pauses
-Complex ventricular ectopy
-Wide QRS complex escape rhythm
-LV dysfunction
What is the incidence of SCD in athletes in the US?
1-2/100,000
What is the most common cause of SCD on the athletic field?
HCM
What might you miss in someone with an “athlete’s heart”?
HCM
True or False: Septal hypertrophy of 13-15mm is seen in 2% of highly trained male athletes
True
What parameters are assessed to differentiate between pathologic and physiologic hypertrophy (HCM v. athletes heart)?
-Family history
-Genetic testing
-Cavity dimensions
-Diastolic parameters
-Sex
-Sports training history
-Stress test
-Response to deconditioning
The probability of HCM over athletes heart increases significantly for which patients?
-FHx HCM
-Pathologic genetic mutation
*Both FHx and genetic test results are + in 50% of patients with HCM… + genetic testing can be helpful in unclear cases
Describe the difference in LV dimensions in HCM v. athletes heart?
-HCM: LV cavity <45mm in adults
-Athletes heart: LV cavity >55mm
Both HCM and athlete’s heart are associated with LA dilation, but it is more pronounced in which?
HCM
True or False: Diastolic function is normal in an athlete’s heart, but abnormal in HCM?
True
How is MRI helpful in differentiating HCM from athletes heart?
Can assess hypertrophy, chamber size ad evidence of myocardial fibrosis (almost universally pathologic)
True or False: ECGs can be overly sensitive in assessing for cardiac hypertrophy (especially if only voltage criteria are used)
True
There are higher rates of SCD in what gender and ethnicity?
Black males
What is the leading cause of SCD in male athletes in the US?
HCM
What is the leading cause of SCD in female athletes in the US?
Coronary anomalies
True or False: Female patients with hypertrophy >13mm are much more likely to have HCM?
True- several studies have documented less septal hypertrophy in elite female athletes
True or False: Black athletes are more likely to have septal hypertrophy in the gray zone?
True
True or False: White athletes with hypertrophy >13mm are more likely to have HCM?
True
What types of sports/training regimens are more likely to be associated with hypertrophy (to help differentiate HCM from athletes heart)?
-Endurance sports (cycling/rowing): More likely to be associated with hypertrophy >13mm
-Isometric activities (weightlifting and wrestling): Unlikely to be associated with septal hypertrophy >12mm
How can exercise testing be helpful to differentiate HCM from athletes heart?
-Athletes: Supranormal O2 consumption
-HCM: Not as good of an O2 consumption, abnormal or blunted BP response to exercise
What trial can be done to differentiate between HCM and athletes heart?
Period of deconditioning (3-6 months)
-See if cardiac parameters normalize… if they don’t, the findings are consistent with HCM and not athlete’s heart
What is the incidence of SCD in athletes?
1-2/100,000 within US
*HCM one of the leading causes (especially in black males)
What measure of septal hypertrophy is considered a gray zone in older adolescents and young adults, but is more likely pathologic in females and those of white race?
13-15mm
What can help to differentiate between athletes heart and HCM?
-FHx
-Genetic testing
-Cavity dimensions
-Diastolic parameters
-Sex
-Sports training history
-Stress test
-Response to deconditioning
What is the most common form of cyanotic CHD?
ToF
Which gender is ToF seen more commonly in?
Near equal distribution between males and females
What results from a failure of cardiac neural crest cells to migrate into the developing heart and/or appropriately differentiate?
Conotruncal defects
Where do the cardiac neural crest cells first migreate?
-To the 3rd, 4th and 6th pairs of pharyngeal arches
-Then into the heart
What do cardiac neural crest cells help facilitate within the pharyngeal arches?
Normal aortic arch and branch PA development
What do cardiac neural chest cells within the heart help facilitate?
Outflow tract septation and semilunar valve formation
What is the cardinal feature or ToF?
Anterior-cephalad deviation of the outlet muscular septum due to abnormal neural crest cell migration
What type of defect is ToF?
Conotruncal
What causes 4 characteristic features of ToF?
Anterior-cephalad deviation of the outlet muscular septum
Aortic arch anomalies seen with conotruncal defects can be explained by abnormalities in what?
Cardiac neural crest cell migration
A right aortic arch is present in what % of patients with ToF?
20-25%
What is the most frequently identified genetic mutation in those with ToF?
Chromosomal microdeletion at 22q11.2 locus
*Occurs in 20% of patients
Conotruncal defect, immunodeficiency, hypocalcemia, facial dysmorphisms, palate defects, developmental abnormalities?
22q11.2 microdeletion syndrome
The likelihood of 22q11.2 mutation being found in patients with ToF or any conotruncal defect is increased by the presence of what?
Aortic arch anomaly
Absence of what gene in those with a 22q11.2 microdeletion results in the loss of a transcription factor important for signaling between neural crest cells and surrounding tissues, resulting in altered neural crest cell migration?
TBX1
Major chromosomal abnormalities are present in what % of cases of ToF?
5-7%
*Includes T21, T18, T13
*T21 is the most common of the 3
Single gene mutations associated with ToF include mutations in what 2 genes?
JAG1
NOTCH2
*Cause Alagille syndrome
Approximately what % of patients with Alagille syndrome have ToF?
10-15%
True or False: Although mutations in many genes have been identified in association with ToF, a genetic influencing factor isn’t found in most patients?
True
What is the most common form of cyanotic CHD?
ToF
What is the most frequently identified genetic mutation in ToF, occurring in 20% of patients?
Chromosomal microdeletion or duplication at the 22q11.2 locus
What defects result from abnormalities of cardiac neural crest cell migration into the developing heart?
Conotruncal defects
How does isolated LA drainage of the RSVC present?
Unexplained cyanosis and clubbing in a patient with an otherwise normal heart
*Rare anomaly
*Degree of cyanosis may be mild
*Children may present later with complications of an obligatory R-L shunt
What problems can occur more frequently as a child gets older with an undiagnosed RSVC to LA?
-Polycythemia
-Decreased exercise tolerance
-Systemic embolic manifestations (stroke, cerebral abscess)
What is the proposed cause of RSVC to the LA?
Deficiency in the wall that separates the RUPV and RSVC along with atresia of the opening of RSVC into the RA
*Most causes of anomalous connection of the RSVC to the LA, the RUPV opens into the RSVC
What is often seen in conjunction with RSVC to the LA?
RUPV drains into the RSVC- Because defect is due to deficiency in the wall that separates the RUPVC and RSVC along with atresia of the opening of the RSVC into the RA
How is RSVC-LA diagnosed?
-Usually echo
-LA/LV often dilated
-Saline contrast echo helps confirm… sequence of appearance of microbubbles after IV injection of agitated saline contrast aids in delineating systemic venous drainage
What would you expect after an injection of agitated saline to the right brachiocephalic vein in a patient with an RSVC-LA?
Rapid opacification of the LA followed by the LV with microbubbles
*If see rare microbubbles in RA/RV, could be due to small L-R shunting across a PFO
What is the current preferred surgical approach for RSVC-LA?
Transect the anomalously connecting RSVC above the opening of the RUPV and reattach it to the RAA
*Venous return from RUPV continues to drain into the LA
True or False: The long-term prognosis is excellent after surgical repair of RSVC-LA?
True
Bounding femoral pulses are seen in infants with what type of heart problem?
Large PDA with large L-R shunt due to significant diastolic runoff from the aorta
A bruit auscultated over the anterior fontanelle is a classic finding in what?
Vein of Galen arteriovenous malformation
Describe the change in blood flow in Vein of Galen malformation?
-Blood flow to brain increased
-Reversal of flow in proximal thoracic descending aorta
-High-output cardiac failure results because of excessive venous return into the SVC
Inspiratory stridor due to tracheal compression is seen with what problems?
-Vascular ring
-Pulmonary sling
How does isolated anomalous connection of the RSVC to LA manifest?
Cyanosis and clubbing
*Onset of symptoms is often insidious
True or False: In most cases of RSVC-LA, the RUPV connects to the RSVC
True
*Recognition of this is important in surgical planning
What is the approach for surgical repair of RSVC-LA?
Transection of the RSVC above the level of the RUPV and reanastomosis to the RAA
Narrow complex tachycardia with a short RP relationship… after adenosine, continuation of tachycardia but with ventriculo-atrial dissociation?
Congenital JET
What is the differential diagnosis of a narrow-complex short RP tachycardia?
-AVRT (concealed and manifest accessory pathways
-JET
-Typical AVNRT
If there is a 1:1 VA relationship during tachycardia, what type of tachycardia is ruled out?
AVRT- Has to be 1:1 VA relationship in AVRT because the atria, AV node, ventricle and AP are all obligatory parts of the circuit
What type of tachycardias are sinus tachycardia and PJRT?
Long RP tachycardia
True or False: PJRT has to have 1:1 VA conduction because it is caused by a decremental concealed accessory pathway?
True
True or False: Congenital JET can present at any age?
True
Which patients with congenital JET are more likely to have incessant and difficult-to-control JET associated with higher morbidity and mortality?
Those under 6 months
How do infants with congenital JET present?
Usually compensated tachycardia, but can also present with CHF and CV collapse
What is the proposed pathophysiology for JET?
Abnormal automaticity of the AV junction
True or False: JET can have either 1:1 VA association or it can have VA dissociation because the atria isn’t an obligatory part of the arrhythmia?
True
What is the first line treatment for congenital JET in infants?
Medical management- Amiodarone most commonly used medication
*Many patients will require combination therapy of amiodarone with a B-blocker and/or Flecainide
*Verapamil and digoxin have also been used, but verapamil needs to be used cautiously in infants
*Ivabradine currently being studied
How does Ivabradine work?
Decreases HR by blocking I(f) currents
True or False: In congenital JET, if rhythm control is able to be achieved, some of the patients will have spontaneous slowing of their junctional rate over time
True (but recurrence can occur later in life
What can be done for cases of medically refractory JET?
Ablation- but risk of AV block isn’t insignificant (especially in younger patient population)
What is the differential diagnosis for a narrow complex short RP tachycardia?
AVRT, typical AVNRT, JET
True or False: JET can have a 1:1 VA association or be VA dissociated
True
What is the most commonly used medication for the management of congenital junctional tachycardia?
Amiodarone
*Often requires combination therapy with B-blockers and/or flecainide
Describe criss-cross atrioventricular valves
-Atria connect to morphologically appropriate ventricle
-Connections are twisted around the long axis of the heart… RV inlet becomes anterior and superior to the LV inlet
-Twisted or criss-cross heart exhibit loss of the normal parallel axes of the ventricular inlets
Describe superior-inferior ventricles?
-Tilting of the ventricular mass along its long axis produces a stacking effect of the ventricles, one on top of the other
-If ventricular mass tilted to the right, morphologic RV becomes superior to morphologic LV
*Can be described as upstairs-downstairs arrangement
True or False: Tilting and twisting of the heart are mutually exclusive mechanisms, but often occur in combination?
True
Describe cardiac rotation
-More rare than tilting or twisting
-Whole heart rotates along its long axis with superoinferior relationships of both atriums and ventricles (RA/RV on top of LA/LV)
-Arterial roots and aortic arch are displaced downward with elongation of the head and neck branches and SVC
-Also called topsy-turvy arrangement
-Not associated with a twisting deformity
What are 3 mechanisms that produce abnormal cardiac positions and relationships?
-Twisting
-Tilting
-Rotation
What results in a criss-cross malformation?
Twisting
What results in superior-inferior ventricles?
Tilting
True or False: Rates of elevated BP or HTN are higher among adolescents compared with younger children?
True
Among youth in the US, what type of HTN is more common?
Primary (v. secondary)
What are features characteristic of kids with primary HTN?
-Overweight or obesity
-Positive family history of HTN in a 1st or 2nd degree relative
-Age of 6 years or older
True or False: High BP in childhood and adolescence is associated with HTN in early adulthood?
True-
And normal BP is associated with the absence of HTN
True or False: Renal US is not needed in children over 6 with normal lab screening results as part of the workup for HTN?
True
Children and adolescents with moderate to severe OSA are at risk for what?
HTN
HTN should be confirmed by ambulatory blood pressure monitoring under what circumstances?
-Elevated BP range for >1 year
-Stage 1 HTN range on 3 occasions
-Stage 2 HTN range on 2 occasions
True or False: Ambulatory blood pressure monitoring is more accurate than clinic BP measures, more reproducible than home BP measures, more predictive of future BP and useful in differentiating “white coat” HTN from true HTN
True
Ambulatory blood pressure monitoring is generally limited to those over what age?
5
When should echo be done in the workup for HTN?
To assess for evidence of end-organ damage once the diagnosis of HTN is established
What is the definition of LVH on echo?
-LV mass >115g/BSA in boys
-LV mass >95g/BSA in girls
-LV mass >51g/m2
A LV relative wall thickness > what is consistent with concentric LVH?
0.42
What is decreased LVEF defined by in the workup of HTN?
<53%
What are the goals for treating hypertension in children and adolescents focused on?
Reducing the risk for target end-organ damage and of HTN related CV disease as an adult
Which children and teenagers should receive pharmacologic therapy for HTN?
-Symptomatic HTN
-Persistent HTN despite lifestyle modifications
-Stage 2 HTN without a modifiable risk factor (obesity)
-LVH on echo
-Any degree of HTN associated with CKD or diabetes therapy
True or False: Mild concentric LVH in someone with HTN qualifies as endo organ damage?
True
What are options for initial medication choice in HTN?
-ACEi
-ARB
-CCB
-Thiazide diuretic
How should anti-hypertensives be started?
-Low dose and increase every 2-4 week until BP is controlled
-Evaluate every 4-6 weeks until BP normalized
-May need 2nd or 3rd agent if BP remains uncontrolled
-Once BP normalized, lifestyle modifications (including weight loss) should be continued
-Follow up every 3-4 months
In patients with HTN who are managed by lifestyle alone, how often is follow-up required?
3-6 months
*Promotes adherence to lifestyle modifications and allows for a reassessment of the need to administer medications
True or False: In children and adolescents with abnormal BP measures, it is important to obtain multiple measurements over time by auscultation with an appropriately sized cuff before diagnosing HTN?
True
When should HTN be confirmed by ambulatory BP monitoring?
-BP in elevated range for >1 year
-Stage 1 on 3 occasions
-Stage 2 on 2 occasions
Normal BP > 13 years?
<120/<80mmHg
Elevated BP > 13 years?
120/<80 to 129/<80mmHg
Stage 1 HTN > 13 years?
130/80 to 139/89mmHg
Stage 2 HTN > 13 years?
> 140/90
Normal BP 1-13 years?
<90th percentile
Elevated BP 1-13 years?
> 90th percentile to <95th percentile
120/80 to <95th percentile
*Whichever lower
Stage 1 HTN 1-13 years?
> 95th percentile to <95th percentile + 12mmHg
130/80 to 139/89
*Whichever lower
Stage 2 HTN 1-13 years?
> 95th percentile + 12mmHg
140/90
*Whichever is lower
How often should BP be done if normal?
Annual
At annual BP checks, what should be done if read is normal?
Lifestyle counseling for weight and nutrition
Flow for workup of elevated BP?
-Initial measurement: Lifestyle counseling
-2nd measurement (repeat in 6 months): Lifestyle counseling and upper/lower BP
-3rd measurement (repeat in 6 months): Lifestyle counseling, ABPM then diagnostic evaluation if confirmed, consider subspecialty referral
Flow for workup of Stage 1 HTN?
-Initial measurement: Lifestyle counseling
-2nd measurement (repeat in 1-2 weeks): Lifestyle counseling and upper/lower BP
-3rd measurement (repeat in 3 months): Lifestyle counseling, ABPM then diagnostic evaluation if confirmed, initiate treatment, consider subspecialty referral
Flow for workup of Stage 2 HTN?
-Initial measurement: Lifestyle counseling, check upper/lower extremity BP
-2nd measurement (repeat and refer to specialty care within 1 week): Lifestyle counseling, ABPM then diagnostic evaluation if confirmed, initiate treatment, subspecialty referral
When should a patient with HTN be sent to the ED?
If patient is symptomatic or BP is >30mmHg above the 95th percentile (>180/120 in an adolescent)
What screening tests should be done for all patients in the diagnostic workup of HTN?
-UA
-Chemistry panel (electrolytes, BUN, Cr)
-Lipid profile (fasting or nonfasting to include high-density lipoprotein (a) and total cholesterol)
-RUS <6 years or those with abnormal UA or renal function
What screening tests should be done for obese patients (BMI >95th %) in the diagnostic workup of HTN?
-UA
-Chemistry panel (electrolytes, BUN, Cr)
-Lipid profile (fasting or nonfasting to include high-density lipoprotein (a) and total cholesterol)
-RUS <6 years or those with abnormal UA or renal function
-Hgb A1C (screen diabetes)
-AST and ALT (screen fatty liver)
-Fasting lipid panel (screen dyslipidemia)
What screening tests are optional based on history, PE and initial studies in the workup of HTN?
-Fasting glucose if high risk for DM
-TSH
-Drug screen
-Sleep study (snoring, daytime sleepiness, apnea)
-CBC (especially with growth delay or abnormal renal function
What are the DASH diet recommendations?
-Fruit/Veggies: 4-5 servings/day
-Low-fat Milk Products: >2 servings/day
-Whole grains: 6 servings per day
-Fish/oultry/lean red met: <2 servings/day
-Legumes/nuts: 1 serving per day
-Oils/fats: 2-3 servings/day
-Added sugar/sweets (sweetened beverages): <1 serving/day
-Na: <2300mg/day
What does critical PS require prior to intervention?
Patency of the ductus for pulmonary blood flow
*Only getting a tiny amount of antegrade flow across the stenotic valve
What other problems is critical pulmonary stenosis associated with?
-Severe RVH
-Variable degrees of hypoplasia of the PV annulus, RV cavity and tricuspid annulus
Why does atrial flow go R-L causing cyanosis in critical PS?
-Right heart obstruction
-Poor RV compliance
What is needed in the first few days of life for critical PS?
Balloon pulmonary valvuloplasty
*Open up the valve and improve antegrade pulmonary blood flow
True or False: Most patients with critical PS s/p balloon valvuloplasty will continue to have at least mild desaturation when the ductus completely closes due to continued R-L atrial shunting?
True
What may need done for a patient with critical PS who has unacceptable cyanosis following balloon pulmonary valvuloplasty?
Continue PGE
What causes persistent cyanosis in critical PS after balloon valvuloplasty?
Continued R-L shunting from poor RV compliance related to RV hypertrophy or RV hypoplasia
What can be helpful to use following balloon valvuloplasty for critical pulmonary stenosis and why?
-Beta blockers
-Reduce HR/improve diastolic filling of the non-compliant RV (especially if there is dynamic RVOT)
Besides issues with RV compliance and atrial R-L shunting what are 2 other causes for persistent cyanosis following balloon valvuloplasty for critical PS?
-TR jet directed towards PFO
-Hypoplastic or stenotic tricuspid valve
True or False: Patients with critical PS s/p balloon valvuloplasty who fail initial PGE wean may tolerate it later once the RV compliance improves?
True
True or False: 22-38% of patients require an alternative source of pulmonary blood flow after balloon pulmonary valvuloplasty for critical PS?
True
*Have smaller Z-scores of pulmonary annulus and tricuspid annulus
*Have higher RV filling pressures
True or False: Many patients with persistent cyanosis following balloon valvuloplasty for critical PS can get by without a re-intervention?
True
*Should demonstrate a persistent need for PGE before a ductal stent or BTT shunt is placed
True or False: Residual R-L atrial shunting and desaturation is expected after balloon pulmonary valvuloplasty?
True- but can improve within the first couple weeks as RV compliance improves
Following balloon pulmonary valvuloplasty, how may patients with critical PS require an additional source of pulmonary blood flow?
1/4 to 1/3
What can present in the newborn period with marked respiratory distress and mild desaturation due to airway compression from dilated/pulsatile pulmonary artery branches and intracardiac shunting?
ToF + PA
*Some newborns may have less severe symptoms if degree of perinatal airway compression is less significant
What type of murmur will most neonates with absent pulmonary valve have?
Prominent systolic and diastolic caused by the combination of PS/PI
Absent pulmonary valve is usually seen in the context of what?
ToF
*APV variant reported in 2-6% of ToF cases
True or False: Absent pulmonary valve can occur when there is an intact ventricular septum, including in the context of tricuspid atresia?
True
Why is the term absent pulmonary valve a misnomer?
There is usually myxomatous rudimentary PV leaflet tissue at the level of a mildly hypoplastic PV annulus
What is the classic finding in absent pulmonary valve syndrome?
-PS/severe PI leading to prenatal development of dilated/pulsatile main and branch PAs
-This results in tracheobronchial compression
-This leads to fetal fluid trapping and hydrops with post-natal respiratory distress with air trapping and lobar emphysema
What is rarely seen in late-term fetuses or live births with absent pulmonary valve?
PDA
True or False: PGE is helpful in ToF + absent PV?
False- usually isn’t a PDA in these patients
What is a proposed etiology of absent pulmonary valve syndrome?
-Agenesis of the fetal ductus arteriosus
-This leads to pulmonary dilation caused by increased blood flow to the fetal lungs
*Could also be that a ductus in a fetus with absent pulmonary valve is more likely to result in early fetal demise
What is a helpful pre-operative management strategy to help stabilize the cardiopulmonary status of neonates with absent pulmonary valve who present with marked respiratory distress and cyanosis?
Prone
How does prone positioning help with absent pulmonary valve?
-Decreases airway compression caused by the anterior-positioned, dilated and pulsatile pulmonary arteries
True or False: If tracheal and bronchial compression lead to intractable respiratory distress in neonates with absent pulmonary valve syndrome, ECMO and/or emergent surgical repair may be needed?
True
What is associated with worse outcomes following absent pulmonary valve repair?
Pre-operative ventilatory dependence
What should be included in repair of absent pulmonary valve sydrome?
Establishing a competent pulmonary valve
True or False: Post-op prone positioning following absent pulmonary valve repair has been reported to improve prognosis?
True
True or False: Despite neonatal surgical intervention in severe cases of absent pulmonary valve syndrome, neonates can have persistent tracheomalacia and chronic lung disease?
True
What two imaging modalities are helpful with suspected absent pulmonary valve syndrome prenatally?
-Fetal echo
-Fetal MRI
What can help with severe respiratory distress seen in neonates with absent pulmonary valve syndrome?
Prone positioning
What does the prognosis of absent pulmonary valve syndrome depend on?
Degree of pulmonary compromise (worse prognosis correlated with need for pre-operative ventilation)
An infant with a wide QRS is defined as > what?
90msec
What is the differential diagnosis for a wide QRS tachycardia in infants?
-Reentrant SVT with aberrancy
-VT
-Antidromic SVT
-Sinus/atrial/junctional tachycardai with an underlying BBB or pre-excitation
What is the most common cause of a wide QRS tachycardia in infants?
SVT with aberrancy
What is the key to making a diagnosis in a wide QRS tachycardia?
-Locate P waves
-Determine VA relationship
In a wide-complex tachycardia, what does VA dissociation rule out?
-SVT with aberrancy
-Antidromic SVT
-Any atrially driven tachycardia
*Possibilities are VT and junctional tachycardia with an underlying BBB
What is the best treatment for a stable VT in an infant?
-IV antiarrhythmic like amiodarone, esmolol, sotalol, procainamide, lidocaine
How can adenosine be helpful in a wide QRS tachycardia?
-If 1:1 VA association: May be secondary to SVT with aberrancy and adenosine would be therapeutic and likely terminate the tachycardia
-If VT with 1:1 VA association: May cause VA dissociation and help diagnose VT
Most VT in infants is what mechanism?
Automatic
Is DC cardioversion helpful in VT in infants?
Not usually, because automatic will briefly terminate tachycardia and automatic focus will restart afte cardioversion
When is cardioversion or defibrillation needed in infants with VT?
If there is hemodynamic compromise
True or False: Infants with VT and a structurally normal heart, normal baseline ECG and no concerning family history tend to have a benign course?
True
*Most have complete resolution of their arrhythmia over the first couple of years after birth
What can be done to pace the atrium and overdrive pace/terminate an SVT?
Transesophageal pacing
*A transesophageal probe may also be helpful to record an atrial electrocardiogram if P waves aren’t easily identifiable
What is key in evaluating a wide QRS tachycardia?
Determining VA relationship
What is the differential diagnosis of a wide QRS tachycardia in infants?
-SVT with aberrancy
-VT
-Antidromic SVT
-Sinus/atrial/junctional tachycardia with underlying BBB or pre-excitation
What can be used to pace/terminate a SVT or to record an atrial electrocardiogram?
Transesophageal probes
