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
