PREP 2020 Flashcards
How can you improve arterial saturation in a post-op Glenn patient with overinflated lungs?
Decrease PEEP- this will return lung volumes to FRC and increase PBF
What circumstance would it be disadvantageous to decrease PEEP in a post-op Glenn patient?
When there is pulmonary edema- this will worsen alveolar O2 exchange and worsen saturations
How does increasing minute ventilation in a post-op Glenn patient effect saturation?
Decrease saturation
-Increased minute ventilation will decrease pCO2, which causes cerebral vasoconstriction, which causes reduced cerebral blood flow which results in decreased return of venous flow through the Glenn which causes desaturation
What are the 2 terms that describe the quantity and relationship of O2 in the blood?
Content
Saturation
How is O2 content expressed?
mL of O2 per 100mL blood
How is oxygen saturation (SaO2) expressed?
Percentage of binding sites on Hgb that are occupied by O2
Healthy individuals with no lung disease breathing room air at sea level have SaO2 between what?
96-98%
What factors affect the O2 content of blood?
PO2
Ventilation and perfusion mismatch
Hgb affinity for O2
Concentration of Hgb
When normally saturated Hgb is circulated to tissues, what % of bound O2 is delivered to the tissues?
25%
What is the typical systemic venous saturation returning to the right side of the heart ?
75%
What is the difference in the saturation of blood leaving the aorta and returning to the right heart?
a-vO2 difference
With normal CO/metabolic demand and no other shunting, what is the average a-vO2 difference?
25 points
What causes a decreased systemic venous saturation and widened a-vO2 differenve?
- Increased metabolic demand- tissues may require more O2 than normal
- If heart unable to upregulate output to meet the demand, tissues will extract more O2 from Hgb than normal leading to a decreased systemic venous saturation and widened a-vO2 difference
What happens to the saturation of Hgb returned from the lungs in the setting of lung pathology (pulmonary edema, PNA, etc)?
Can be decreased
-Ability of the alveoli to transfer O2 to pulmonary arterioles is limited
In the setting of lung pathology, what plays a key role in the determination of the SaO2?
Partial pressure of O2 (O2 tension)
What represents the partial pressure when gases are mixed?
Sum of the pressures that each gas in the mixture exert if alone
When a mix of gases comes into contact with a membrane across which they can diffuse, what is the rate of diffusion dependent upon?
Relevant gradient of the partial pressure of the gas across the membrane (not the concentration of the gas)
True or False: Concentration and partial pressure have a direct relationship in the gas phase?
True
Why is blood able to carry large concentrations of O2?
Hgb high affinity for O2
How do increases in mean airway pressure or addition of supplemental O2 lead to an increase in arterial O2 saturation?
By increasing alveolar partial pressure of O2
How does positive airway pressure improve alveolar O2 tension?
Recruits collapsed alveoli
What can help to increase alveolar O2 tension in regions of low ventilation?
Supplemental oxygen
Lung pathology (pulmonary edema or PNA) can lead to what?
Pulmonary venous desaturation
What measures can improve pulmonary venous and systemic saturation?
- Increasing airway pressure
- Supplemental O2
*Both can increase alveolar O2 tension, improve diffusion and improve pulmonary venous and systemic saturation
What causes LQTS3?
Gain of function mutation on SCN5A (regulates cardia Na channels
True or False: B-blockers help decrease the number of arrhythmic events in patients with LQTS3, but not to the same extent as 1 and 2?
True
What medication reduces the number of arrhythmic events in patients with LQTS, in particular those with type 3 disease?
Mexiletine
How does mexiletine work?
- Class IB antiarrhythmic
- Inhibits inward Na current
- By blocking late Na current, leads to decrease of AP duration and shortens the ERP
Amiodarone, dofetilide and sotalol are what class of antiarrhythmics?
III
How do class III antiarrhythmics work?
- Inhibit K delayed rectifier currents during phase 2 of the AP
- Prolong AP duration and ERP
What change is seen on ECG in patients receiving class III antiarrhythmics?
Prolongation of the QT interval
Class III antiarrhythmics are contraindicated in patients with what?
Long QT syndrome
True or False: All class III antiarrhythmics have the potential to be pro-arrhythmic?
True- TdP and ventricular arrhythmias most concerning
What needs to be monitored on all patients started on a class III antiarrhythmic?
ECG for the QTc
What are possible side effects of amiodarone?
- Thyroid dysfunction (hypo or hyper)
- Skin discoloration
- Photosensitivity
- Hepatitis
- Corneal deposits
- Pulmonary toxicity
- Pro-arrhythmic
What medication can be effective in the treatment of patients with long QT syndrome type 3?
Mexiletine
What class of antiarrhythmics are contraindicated in patients with LQTS?
III
What is the best testing to make a diagnosis of aortic dissection?
CTA
What is the classification system what categorizes aortic dissection based on anatomic location?
Stanford
What is a type A aortic dissection?
Involves the ascending aorta
What is a type B aortic dissection?
All other dissections besides those involving the ascending aorta
What is the most common type of aortic dissection?
A
True or False: In aortic dissection, the site of the primary intimal tear doesn’t determine classification?
True
- Type A doesn’t have to originate in or be confined to the ascending aorta
- Type B cannot include the ascending aorta
What is a potential, but uncommon complication of aortic stent placement?
Aortic dissection
What patient group is at increased risk of spontaneous aortic dissection and iatrogenic dissection?
Turner
What is the most common presenting symptom of an aortic dissection?
Sudden onset of chest or abdominal pain described as sharp, tearing or ripping
*Chest pain or back pain is more common than abdominal pain
What type of aortic dissection is more likely to be associated with anterior chest pain?
Type A
What type of aortic dissection is more likely to be associated with back pain?
Type B
With an aortic dissection, the presence of abdominal pain should raise suspicion for what?
Mesenteric vascular compromise from dissection extending into abdominal aorta
Besides chest/back/abdominal pain, what are other signs and symptoms of an aortic dissection?
Pulse deficit, heart murmur (new AI if type A involves aortic valve), focal neurologic deficits, hypotension
What should be considered for someone with abdominal pain and HTN after stent placement?
Post-coarctectomy syndrome
*Usually postsurgical phenomenon
What causes postcoarctectomy syndrome?
Paradoxical HTN as a result of rebound activation of the sympathetic nervous system and renin-angiotensin system
How does postcoarctecomty syndrome cause abdominal pain?
Paradoxial HTN can be severe and result in mesenteric arteritis leading to abdominal pain
Besides a CTA, what other tests can help with diagnosis of an aortic dissection?
TEE and MRI
*TTE or abdominal US aren’t as sensitive or specific as a TEE or MRI
What is seen on CXR in aortic dissection?
Mediastinal widening (most common in type A, but also occurs in type B)
Stent-associated aortic dissection may be increased in patients with what condition?
Turner
What are causes of palpitations?
- Arrhythmias (SVT, v-tach, PACs, PVCs)
- Anxiety/emotions
- Anemia
- Hyperthyroidism
- Fever
- Medication effects
- Inappropriate sinus tachycardia
- POTS
What is a form of autonomic dysfunction which includes palpitations and presyncope with prolonged standing or physical activity, gradual improvement of symptoms with rest in the seated or supine position, generalized fatigue, nausea, mental clouding and dependent bluish discoloration of the lower extremities?
POTS
True or False: A gradual improvement in palpitations and presyncopal symptoms is not consistent with an arrhythmia?
True
*Arrhythmia more likely if abrupt onset and termination described
What type of patients most often get POTS?
Females between 15-25 years
How is POTS diagnosed?
Increase in HR (>30 for adults or > 40 for pediatrics) without a decrease in BP (>20mmHg drop in SBP) within 10 minutes of moving from a supine to standing position
What are more detailed testing options for the diagnosis of POTS?
- Measurement of supine and upright plasma epinephrine and norepinephrine levels
- Thermoregulatory sweat test
*Not typically used and POTS often diagnosed by orthostatic vital signs alone
True or False: Most patients with d-TGA don’t have a genetic syndrome?
True (96%)
In patients diagnosed with DiGeorge, what % have d-TGA, ToF and TA?
- d-TGA: 1%
- ToF: 20%
- TA: 6%
What % of patients with Turner syndrome (45,X) have cardiac disease?
50%
What are most common cardiac issues in Turner syndrome?
Bicuspid AoV, CoA, dilated ascending aorta
Trisomy 21 has what % incidence of CHD?
50%
What are the majority of congenital heart defects seen in trisomy 21?
-Septation: AVSD, VSD, ASD
What % of d-TGA patients have non-cardiac anomalies?
<10%, very low compared to others
What is the most common associated cardiac anomaly in d-TGA?
VSD (up to 50% of cases)
What is more common in the setting of d-TGA and a malalignment VSD?
LVOTO (can also include PV abnormalities)
True or false: TGA isn’t strongly associated with any particular genetic syndrome?
True
Defects in genes that control what are associated with TGA?
Laterality
What causes Ebstein anomaly?
Failure of delamination of the septal and posterior leaflets of the TV leading to apical and anterior displacement of the functional TV annulus into the RV and valve dysfunction
What is the atrialized portion of the RV in Ebstein?
Portion of RV proximal to the functional annulus which becomes thin-walled
True or False: The severity of Ebstein anomaly can vary greatly?
True-
- Mild: Minimal TV dysfunction and few symptoms
- Severe: Small portion of normal RV, severe TR, little to no effective anterograde flow through right side of heart
According to newer studies, what is the perinatal mortality rate associated with fetal diagnosis of Ebstein anomaly?
40-50% (used to be up to 80%)
What problems result from severe tricuspid valve dysfunction in utero that lead to increased parinatal mortality in Ebstein?
- Right heart dilation due to back/forth flow (especially RA and atrialized RV)
- Progressive dilation can cause cardiomegaly which may lead to lung hypoplasia
- Decreased CO (poor RV output and impaired LV hemodynamics due to RV dilation)
What are the potential problems that can develop in utero with the RV and RVOT in Ebstein?
- RV can be dysfunctional
- May have functional PA- RV can’t overcome afterload to open PV
- Poor flow through the RVOT early in gestation can lead to a structural RVOTO or anatomic PA
- PA results in L-R ductal shunting
- With functional pulmonary atresia, may develop PI which further increases volume load on RV
What may be needed for neonates with Ebstein and anatomic PA or significant RVOTO after birth?
Ductal patency for adequate pulmonary blood flow… will require intervention in neonatal period to establish a stable source of pulmonary blood flow
What should be considered regarding the PDA in an infant with Ebstein and functional PA?
- As PVR falls normally, RV may be able to generate sufficient pressure to overcome afterload and open PV
- Keeping PDA open may be counter-productive because it would keep afterload high in RV and limit this forward flow
The presence of PI in patients with Ebstein and functional PA is indicative of what?
High RV afterload
The presence of PI in patients with Ebstein and functional PA leads to what?
Circular shunt and further volume loading of the right side of the heart
What predictors of a poor outcome in Ebstein anomaly seen on fetal echo?
- Pulmonary insufficiency
- Pulmonary atresia (functional or anatomic)
- Severe RA and atrialized RV dilation
- Increased CT ratio
- Hydrops
- Larger TV annulus
- LV dysfunction
- Low TR jet velocity
What is the Celermajer index?
Ratio of the area of the RA and atrialized RV to the area of the normal portion of the RV and LA/LV
- Measured using 4C of fetal heart
- Higher number implies higher risk for mortality
True or False: ASD are seen in most patients with Ebstein anomaly?
True
What % of patients with Ebstein have WPW?
10-30%
True or False: Arrhythmias during gestation increase perinatal mortality in Ebstein?
False- Can occur during gestation, but haven’t been shown to have a large effect on perinatal mortality
*Arrhythmias are overall common in patients with Ebstein anomalty
Fetuses with Ebstein and what finding on fetal echo throughout gestation have the highest rates of survival and biventricular circulation?
Antegrade pulmonary blood flow (R-L ductal shunting)
How does severe Ebstein anomaly lead to functional PA?
When RV is unable to generate enough pressure to open PV
Which fetuses with Ebstein are at the highest risk for perinatal mortality?
- Severe right-sided heat dilation
- PI
- Absence of anterograde pulmonary blood flow
- Hydrops
- LV dysfunction
What physical exam finding is consistent with pulmonary hypertension?
Single, loud S2
High-frequency systolic murmur along LLSB?
Tricuspid regurgitation
When do most patients with cor triatriatum have onset of symptoms?
Within first few years of age
*Symptoms of PH can be subtle or midleading and delay diagnosis (may be diagnosed with asthma, etc)
What is the management of patients with cor triatiatum and elevated PA pressure?
Surgical resection of the obstructive membrane
What has to be ruled out in the evaluation of pulmonary hypertension?
Left-sided obstructive heart lesions
*Echo +/- CT if echo inconclusive or if lung pathology is a concern
What could happen with the use of O2 or a pulmonary vasodilator in cor triatriatum?
May worsen pulmonary edema and clinical status
True or False: There are many anatomic variants of cor triatriatum?
True
What is it called when all or some of the pulmonary veins enter a pulmonary venous chamber that joins the LA through a narrowed opeining?
Cor triatriatum
What are the signs and symptoms of obstructive cor triatriatum?
Pulmonary venous obstruction (pulmonary HTN and right-sided heart failure)
True or False: An isolated right aortic arch with left-sided ductus arteriosus and aberrant left subclavian results in a vascular ring?
True
What are vascular rings?
Heterogenous group of vascular abnormalities that encircle the trachea and esophagus
How is a fetal right aortic arch identified?
When the transverse aortic arch passes to the right of the trachea
How is a left arterial duct identified on a fetal echo?
Passes to the left of the trachea
How does a right aortic arch with left ductus appear on fetal echo in comparison to a left-sided aortic arch and left duct?
- Right arch/left duct appears U-shaped
- Left arch/left duct appears V-shaped (both pass on the same side of the trachea)
What is the path of an aberrant left subclavian artery off of a right aortic arch on fetal echo?
Arises distally off the aorta, courses from right side of spine behind trachea/esophagus and heads left
True or False: Patients with a vascular ring due to a right aortic arch, left duct and aberrant left subclavian artery rare have symptoms of airway or esophageal compression in the neonatal period?
True
About what % of patients with a right arch, left duct and aberrant left subclavian artery develop symptoms of compression (dysphagia, stridor, recurrent URIs)?
20-25%
At what age do patients with right arch, left duct and aberrant left subclavian artery develop symptoms of compression (if they ever develop these) on average?
7 months
Fetal right aortic arch without intracardiac abnormalities is associated with extracardiac malformations involving what?
GI system or urinary tract
*Esophageal atresia can rarely be seen with this
Up to 10% of patients with an isolated right aortic arch have what genetic finding?
22q11.2 gene deletion
What should be offered to all patients with an isolated right aortic arch?
Genetic testing (looking for 22q11.2 deletion
What are the 4 goal of prenatal counseling following a diagnosis of CHD?
- Accurate diagnosis of the malformation
- Clear/truthful picture of the prognosis
- Outlining available management and treatment options
- Help parents reach decisions concerning form of management that is best for them
Prenatal counseling should offer information on that things?
- Nature of the specific diagnosis
- Possible associations with specific genetic anomalies
- Natural history
- Range of treatment and management strategies
- Long-term post-natal prognosis
True or False: Right aortic arch with aberrant left subclavian artery is associated with extracardiac and genetic anomalies including 22q11.2 deletion?
True
True or False: Most patients with a prenatal diagnosis of right aortic arch don’t become symptomatic or require surgical intervention
True
The current PALS guidelines for pulses v-tach or v-fib include what?
- High quality CPR
- Quick defibrillation with 2-4 J/kg
What should be considered in cases of shock-refractory pVT/VF?
Lidocaine or amiodarone
*If patient has LQTS as cause of arrest, avoid amiodarone
Amiodarone should be avoided in what patients?
LQTS
What class is amiodarone?
III
Why does amiodarone increase the risk of ventricular arrhythmias in LQTS patients?
Leads to QT prolongation
Besides lidocaine or amiodarone, what can be considered in cases of torsades de pointes which is refractory to defibrillation?
Mg Sulfate
How does adenosine work?
Blocks the AV node
Adenosine can be used as a treatment option in patients with what rhythms?
- SVT
- Wide QRS tachycardia that is stable with a pulse
What is one of the most common causes of a wide QRS tachycardia in children?
SVT with aberrancy
Besides lidocaine or amiodarone, what are 2 other medications that can be used for ventricular arrhythmias, but aren’t part of PALS guidelines for pVT/VF?
Sotalol and emolol
What class is sotalol?
III
Which patients should you avoid sotalol in?
LQTS
What should be considered in cases of shock-refractory pulseless ventricular tachycardia or ventricular fibrillation?
Lidocaine or amiodarone
What should be done immediately for pulseless ventricular tachycardia or ventricular fibrillation?
Quick defibrillation with 2-4J/kg
What anti-arrhythmics should be avoided in patients with known or suspected LQTS?
Class III anti-arrhythmic agents (amiodarone, sotalol, etc)
What can occur after CPB that contributes significantly to morbidity and mortality in pediatric cardiac patients?
AKI
Cardiac-surgery AKI is reported in up to what % of pediatric patients?
33-50%
Cardiac-surgery associated AKI is associated with what?
More complex surgeries and longer CPB time
What should be considered in a post-op patient with low urine output or electrolyte abnormalities?
AKI
What should be considered when prescribing medications for a post-op patient?
Risk for nephrotoxicity with potential AKI…renally dose meds and avoid nephrotoxic meds as able
What is newest and most commonly used system to categorize AKI?
Kidney Disease: Improving Global Outcomes (KDIGO)
What are the 2 factors considered in the KDIGO classification system for AKI?
Serum creatine and urine output
What are 2 newer biomarkers which may be used in the monitoring of renal function after cardiac surgery?
- NGAL (neutrophil gelatinase-associated lipocalin)
2. Cystatin-C
What are some medications commonly used in pediatric cardiac patients that may need dose-adjustment based on renal dysfunction?
- Vancomycin
- Enoxaparin
- Cefepime
- High-dose ASA
- NSAIDS (ibuprofen)
- Aminoglycosides (gentamicin)
- Histamine receptor antagonists (ranitidine)
- ACEi
- Certain diuretics
- Narcotics (morphine)
True or False: Low-dose ASA hasn’t been linked to an increased risk of nephrotoxicity?
True- Dose adjustments not needed unless GFR is <10
Urine output < what is a sign of AKI according to the KDIGO classification system?
<0.5mL/kg/hr (for 6-12 hours)
An increase in creatine level to greater than what from baseline is a sign of AKI according to the KDIGO classification system?
> 150% from baseline
What is stage 1 AKI per KDIGO?
- Serum creatine 1.5-1.9 times baseline or >0.3mg/dL increase
- UOP <0.5mL/kg/hr for 6-12 hours
What is stage 2 AKI per KDIGO?
- Serum creatine 2-2.9 times baseline
2. UOP <0.5mL/kg/hr for >12 hours
What is stage 3 AKI per KDIGO?
- Serum creatine 3 times baseline or increase in serum creatine to >4mg/dL or initiation of renal replacement therapy or in patients <18 years decrease in eGFR to <35mL/min
- UOP <0.3mL/kg/hr for >24 hours or anuria for >12 hours
What is a risk with benign ventricular ectopy?
Tachycardia induced cardiomyopathy
In adults, tachycardia-induced cardiomyopathy is unlikely with a % PVC burden under what?
16-24%
*Some cases have been reported with PVCs low as 10%
What is the PACES/HRS recommendation for follow-up in children with ventricular ectopy and a structurally normal heart?
Longitudinal follow-up of patients with >10% burden of PVCs to monitor for progression to cardiomyopathy
What needs to be ruled out when evaluating a patient with PVCs?
Rule out any malignant causes of arrhythmia (myocarditis, cardiomyopathy, tumors, CPVT, LQTS, ARVC, etc)
What should be done as part of the workup for a patient presenting with PVCs?
ECG, echo, Holter, personal history, family history, exercise stress test
An exercise stress test in a class 1 recommendation in patients with what type of ventricular ectopy?
Multiform or complex (bigeminy, couplets, NSVT)
An exercise stress test is a class 2A recommendation in patients with what type of ventricular ectopy?
Simple (no bigeminy, couplets, NSVT)
True or False: The early stages of ARVC can present with monomorphic PVCs of RVOT origin and can be difficult to diagnose?
True
In addition to history, physical, ECG, echo, exercise stress test and holter, what other things are recommended when there is suspicion for ARVC?
- MRI (2a for children, 2b for older infants)
- Signal-averaged ECG (2b)
What factors would raise clinical suspicion for ARVC?
- RV wall motion abnormality on echo
- RVOT enlargement on echo
- Abnormal T-wave inversion in anterior precordial leads in patients >14 years
- Epsilon wave on ECG
- V-tach with LBBB morphology and superior axis
- Concerning family history
Besides ECG, Holter, echo, exercise test and H&P what should be done for a patient with incessant or complex ventricular ectopy?
MRI (class 2a) to rule out myocarditis
True or False: Isolated, monomorphic ventricular ectopy in patients with structurally normal hearts is typically benign
True
In patients with ventricular ectopy, what baseline testing should be done at a minimum to rule out malignant causes of arrhythmia?
- ECG
- Echo
- Holter
What testing in addition to ECG, echo and holter should be strongly considered in the setting of multiform or complex ventricular ectopy?
Exercise stress test
What specific testing is helpful with concern for ARVC?
CMR or signal-averaged ECG
What specific testing is helpful with concern for myocarditis in the setting of incessant or complex ventricular ectopy?
CMR
What with an ectopy burden > what should be followed longitudinally to ensure that ventricular function remains normal?
10%
Complete heart block with marked bradycardia, elevated CRP, Tn, BNP, normal systolic function, trivial pericardial effusion?
Viral myocarditis
True or False: Complete heart block is a fairly unusual, but well described finding in viral myocarditis?
True
Why would complete heart block result in fatigue and syncope?
Heart can’t increase CO in response to activity due to the heart block
What are common symptoms of viral myocarditis?
Dyspnea, chest pain
What is myocarditis?
Generic term to describe an inflammatory response of the myocardium to pathologic agents (infectious or noninfectious)
What is the most common cause of infectious myocarditis?
Viral (but can also get bacterial, fungal, parasitic, rickettsial and protozoal)
What are some non-infectious causes of myocarditis?
- Autoimmune (SLE or rheumatic fever)
- Medications
- Kawasaki disease
What is the gold standard test to confirm the presence of myocarditis?
Endomyocardial biopsy demonstrating myocardial inflammation
*Seldom done in real life
What if the favored diagnostic modality for myocarditis?
CMR- Detects myocardial edema and/or inflammation
Besides viral myocarditis, what are the most common etiologies for myocarditis presenting with heart block?
Lyme disease
SLE
What are arrhythmias that commonly occur with acute and subacute myocarditis?
Atrial and ventricular tachyarrhythmias
- Can also see complete heart block
- Presence of arrhythmias associated with a worse outcome
True or False: Despite clear evidence that IVIG improves outcomes in myocarditis, many centers will give IVIG to patients with fulminant myocarditis, hemodynamic instability and/or potentially lethal arrhythmias like complete heart block)
True
What is the most common ECG finding in acute rheumatic fever?
Prolonged PR interval (varying degrees of heart block)
When does congenital complete heart block typically present?
At birth or shortly after (rarely can be seen in older children)
True or False: Complete heart block is a common arrhythmia seen in Kawasaki?
False
True or False: Complete heart block is an unusual, but well-described presenting sign of acute myocarditis in children?
True
True or False: Most patients with arrhythmias or conduction disturbances associated with acute myocarditis will have resolution of their arrhythmias/conduction disturbances as their myocarditis resolves?
True
*But recurrent/persistent arrhythmias have been reported
What is the preload reservoir for the RV?
Systemic venous bed (outside of the thorax)
What is the preload reservoir for the LV?
Pulmonary vascular bed (within thorax)
What is the afterload reservoir for the RV?
Pulmonary vascular bed (within thorax)
What is the afterload reservoir for the LV?
Systemic arterial bed (outside of thorax)
How does an increase in intrathoracic pressure affect the RV?
Increase afterload
Increase workload
If there is impairment of the systolic or diastolic RV function, what does an increase in intrathoracic pressure result in?
- Increase in RV workload
- Decrease in output of the RV
- Decrease in preload to the LV
- Decrease CO
How was a increase in intrathoracic pressure effect the LV?
- Decrease afterload
- Decrease workload
If there is impairment of the systolic or diastolic LV function, what does an increase in intrathoracic pressure result in?
- Decrease in transmural gradient (pressure difference between the intrathoracic LV cavity and extrathoracic systemic vascular space)
- Pressure difference LV has to overcome to eject same volume decreases and CO increases
*What is seen in positive-pressure mechanical ventilation
How does an increase in PEEP influence intrathoracic pressure?
Increases it
An increase in intrathoracic pressure has what effect on the RV?
- Increased afterload
- Can result in impairment and decreased output in a noncompliant/hypertrophied RV
With a R-L shunt, which is higher, measured arterial pCO2 or expired end-tidal pCO2?
Measured arterial pCO2
*With a R-L shunt, a portion of the CO never reaches the lungs to exchange pCO2
In a R-L shunt, what does the arterial-to-expired pCO2 gradient correlate with?
Degree of R-L shunt
- Ex: If Qp:Qs = 0.6:1 and arterial pCO2 = 55, end tidal pCO2 would be 33
- 0.6/1 = 33/55
Arterial to end-tidal pCO2 gradients are common and expected in patients with what type of shunt?
R-L
Arterial to end-tidal pCO2 gradients directly correlate with what?
Degree of shunting
CoA is associated with a bicuspid AoV in what % of cases?
50-80%
What are long-term issues in regard to repaired CoA of the aorta?
- Aneurysm at site of prior repair
- Residual stenosis or re-coarctation
- Long-term HTN
- Increased risk of acquired CV disease
- Cerebral aneurysm
- Other associated left-sided heart obstructive lesions
What are long-term concerns in patients with bicuspid AoV?
- Progressive stenosis or regurgitation
- Resultant LV effects: Hypertrophy, dilation, dysfunction
- Ascending Ao aneurysm
A dilated AscAo > what is considered a class I recommendation for surgical replacement of the ascending aorta?
> 5.5cm
In which individuals would you consider surgery for aortic dilation >5cm?
- Family history of early dissection
- Personal history of rapid progression
- Aortopathies (may be considered at a center for excellence in aortopathy)
*Otherwise, intervene at >5.5cm
For stenosis or regurgitation with a bicuspid AoV, what is the indication for intervention largely based on?
Symptoms
In chronic AI, if the regurgitation is considered severe and LV function is preserved, it is reasonable to consider AoV replacement if the LVESD is > what?
50mm
In chronic AI, if the regurgitation is considered severe and LV function is preserved, it is reasonable to consider AoV replacement if the LVEDD is > what?
65mm
In an asymptomatic person with severe AS and a peak velocity >4M/sec, AoV replacement may considered under what circumstances?
- LVEF <50%
- Abnormal exercise stress test with decreased exercise tolerance or fall in BP
- Undergoing other cardiac surgery
True or False: The echo gradient at the level of the aortic isthmus is often overestimated following CoA repair?
True
What are the indications for surgery in the setting of re-CoA after repair?
- Clinical cuff gradient differential of at least 20mmHg
- Evidence of significant gradient and collateral vessels (usually seen by 3D imaging)
A dilated AscAo > what is considered a class I indication for surgery in patients with bicuspid AoV associated aortopathy?
> 5.5cm
In cases of bicuspid AoV with resultant AS or AI, what help guide indications for surgery?
Symptoms
Individuals with repaired CoA and cuff gradients > what may be considered for intervention?
20mmHg from upper to lower extremity
What is the definition of DORV with noncommitted VSD?
- VSD distant (greater than aortic diameter) from both arterial valves
- Both great vessels arising fully from the RV
- Double conus
*Others have described non-committed VSDs as those that don’t open between the limbs of the septal band (like they do in other forms of DORV)
What is a significant risk following intracardiac baffle repair of a remote VSD in DORV with noncommitted VSD?
LVOTO (can be late onset)
Where are most stenoses seen in LVOTO following intracardiac baffle repair of a remote VSD?
- Aortic annulus
- Baffle-patch/muscular structures
- VSD
*LV undergoes geometric changes in which the VSD is used as a new LVOT pathway… bulge of the underlying septal or subaortic conal muscle is often main cause of obstruction (v. Ao annulus and tunnel entry stenosis)
What is a proposed reason for late-onset LVOTO following following intracardiac baffle repair of a remote VSD?
Somatic outgrowth…material for intracardiac baffle is unable to grow
What is repair of DORV with non-committed VSD and normally related great arteries associated with?
Late-onset complex LVOTO
What levels can LVOTO after intraventricular tunnel repair to the aorta develop at?
- Aortic annulus
- Baffle patch/muscular structures
- VSD
True or False: In all cases of IAA, the femoral pulses are reduced and the lower extremity saturations are decreased?
True
In IAA, absence/reduction of the brachial pulses and decreased upper extremity saturations suggests what anatomy?
Both subclavian arteries arising distal to the interruption
*Like IAA B with aberrant subclavian
True or False: An infant with IAA type B with an aberrant subclavian artery would be expected to have weak carotid pulses?
False
What is IAA type B with an aberrant subclavian artery commonly associated with?
DiGeorge
What is a complete separation of the ascending and descending aorta?
IAA
Where is the interruption in IAA A?
Distal to the most distal subclavian artery (usually left subclavian artery)
Where is the interruption in IAA B?
Between the left carotid and subclavian arteries
Which type of IAA is frequently associated with DiGeorge?
B
Which type of IAA has a high incidence of an aberrant right subclavian arising from the descending aorta?
B (some estimates high as 50%)
Where is the interruption in IAA B?
Between the carotid arteries
What are the key physical exam findings in all types of IAA?
- Differential cyanosis
- Differential pulses
- Usually between upper and lower extremities
- If aberrant subclavian, between head and extremities
True or False: Most patients (>70%) with IAA have a VSD?
True
What type of VSD is often seen in IAA (50% of Type A, 75% in Type B)?
Posterior malaligned VSD
What is the result of the posterior malaligned VSD often seen in IAA?
LVOTO
Besides a VSD and potential LVOTO, what is another common finding in IAA?
Bicuspid AoV
Interrupted aortic arches are almost always which side?
Left
*Right IAA has been reported in DiGeorge, even rare variant of right aortic arch and aberrant subclavian
Which type of IAA is associated with DiGeorge?
B
An aberrant subclavian artery is most common in what type of interruption?
B (associated with DiGeorge)
What is the first-line therapy for a neonate with a hemodynamically significant PDA?
Pharmacologic closure (if no contraindications)
*Although some centers use device closure or surgical ligation as preferred initial management
What are the most commonly used medications to close a PDA?
Ibuprofen (IV or PO)
Indomethacin (IV)
How do ibuprofen/indomethacin close a PDA?
Inhibit cyclooxygenase (COX) which in turn decreases prostaglandin production, which should result in ductal closure
Indomethacin and ibuprofen result in ductal closure what % of the time when used in an extremely low birth-weight neonate?
70-80%
What are the adverse effects of indomethacin and ibuprofen when used for PDA closure?
- GI bleed
- Spontaneous intestinal perforation
- NEC
- Renal impairment
- IVH
Is ibuprofen or indomethacin preferred for closure of a PDA and why?
Ibuprofen- lower risk of NEC and transient renal insufficiency
The COV inhibitors (ibuprofen/indomethacin) are contraindicated in what neonates?
- Suspected NEC
- Grade 3 or 4 IVH
- Clinical bleeding tendency
- Thrombocytopenia with Plt <60
- UOP <1mL/kg/hr
- Serum creatine level >1.5
- BUN >20
What needs to be closely monitored in a neonate receiving ibuprofen or indomethacin for PDA closure?
- Bleeding
- Early signs of NEC
- Decreased UOP
- Increased creatine
- Decreased platelets
How many 3-day courses of ibuprofen/indomethacin can be used for PDA closure?
Typically 2… if duct remains open, additional doses unlikely to be effective
Besides the COX inhibitors, what other medication has been shown to result in ductal closure for a premature neonate with symptomatic PDA?
Acetaminophen
What are class I indications for placement of a permannent pacemaker?
- Complete AV block with a wide QRS escape rhythm
- Advanced 2nd/3rd degree AV block with symptomatic bradycardia, ventricular dysfunction or low CO
- Post-op advanced 2nd or 3rd degree AV block that isn’t expected to resolve or that persists at least 7 days after surgery
- Congenital 3rd degree AV block with complex ventricular ectopy
- Congenital complete AV block with a ventricular rate <55npm or with CHD and a ventricular rate <70npm
How can noninvasive testing like Holter or exercise stress testing be used in advanced 2nd or 3rd degree heart block?
- See if there is ever any conduction
- See how conduction changes with an increased catecholaminergic state
How is an EP study helpful in 2nd degree AV block?
Can be used to evaluate the level of block (supra-Hisian v. infra-Hisian)
True or False: Invasive testing of conduction isn’t usually indicated for complete heart block?
True
AV block with associated septal defect and bone abnormality in the upper extremity?
Holt-Oram
TBX5
Holt-Oram
When are accurate measurements of QTc ideally done?
Sinus rhythm with normal QRS
What effect does Theophylline have on the sinus node and AV conduction?
- Stimulate sinus node
- Not expected to enhance AV conduction
What should be done for a wide QRS escape rhythm in a patient with complete AV block?
Pacemaker (class I indication)
What are the risk factors for sudden death in patients with HCM?
- Severe septal hypertrophy >30mm or Z-score >6
- FHx of sudden death resulting from HCM
- Hypotensive response during exercise
- Unexplained syncope
- Ventricular tachycardia
*Newer data show significant delayed enhancement on CMR is additional risk factor for SCD
**Adult risk factors, not as well defined for pediatrics
How many risk factors need to present to indicated placement of an ICD as primary prevention in HCM?
1 for adults, pediatric centers usually prefer 2+
- Severe septal hypertrophy >30mm or Z-score >6
- FHx of sudden death resulting from HCM
- Hypotensive response during exercise
- Unexplained syncope
- Ventricular tachycardia
*Newer data show significant delayed enhancement on CMR is additional risk factor for SCD
True or False: LVOTO in HCM has not been correlated with SCD?
True
*LVOTO can cause symptoms and need for myectomy
What types of cardiomyopathy has preexcitation (WPW) been associated with?
- HCM
- LVNC
What circumstance can pre-excitation lead to SCD?
If there is atrial fibrillation in a patient with a rapidly conducting manifest accessory pathway
What illicit drugs can cause MI?
- Cocaine
- Amphetamines (MDMA, ecstasy, 3,4-methylenedioxymethamphentamine)
- Marijuana
How do cocaine and amphetamines cause MI?
- Activations of nervous system leading to tachycardia, hypertension and vasoconstriction (including coronary artery circulation)
- Coronary thrombosis
- Blocking Na/K channels leading to arrhythmia (only cocaine)
How does marijuana cause MI?
- Low-moderate doses stimulates the sympathetic nervous system leading to tachycardia, hypertension (though at higher doses, does the opposite activating the parasympathetic nervous system causing bradycardia and hypotension)
- Coronary vasospasm
When are the CV effects and risk of MI highest after marijuana use?
Within 1 hour
True or False: Marijuana can lead to atrial arrhythmias?
True- Marijuana has some EP effects like decreased AP duration and refractory period
What factors increase the risk of marijuana use for MI?
- Concomitant alcohol or tobacco use
- Concurrent use of other illicit drugs (cocaine, amphetamines, etc)
What form of marijuana is often more potent with more profound CV effects?
Synthetic cannabinoids (K2, spice, etc)
Under what circumstance would a central nervous system depressant (like opioids or benzodiazepines) cause tachycardia or hypertension?
Withdrawal
-Use on own leads to bradycardia and hypotension
What problems can chronic heavy alcohol use lead to?
Hypertension and cardiomyopathy
What illicit substance is used commonly in adolescence that can lead to MI and SCD?
Marijuana
What causes MI/SCD with marijuana use?
Hypertension, tachycardia, potentially coronary vasospasm
What illicit substances aren’t used as common as marijuana in adolescents, but have a higher risk of MI and SCD?
Cocaine and stimulants
What causes MI/SCD with cocaine/stimulant use?
- Sympathetic nervous system activation
- Coronary vasoconstriction
- Acute thrombosis
- Direct EP effects
What are patients who get transcatheter pulmonary valves at increased risk for as compared to patients who get a surgical bioproshetic pulmonary valve?
Endocarditis
What component of social history would have an impact on decision regarding valve replacement?
IV drug use- Increased risk for endocarditis
What are two major known risk factors for endocarditis that should be evaluated prior to any type of valve replacement?
- IV drug use
- Poor dental health
What changes are expected on CPET for a patient with reduced ventricular function (peak VO2, HR response, O2 pulse, VAT)?
- Lower than normal % of predicted peak VO2
- Chronotropic incompetence with inadequate or inappropriate HR response to exercise
- Reduced rise in O2 pulse
- VAT lower than predicted
What changes are expected on CPET for a patient with significant AV valve disease (peak VO2, O2 pulse, VAT)?
- Lower than normal % of predicted peak VO2
- Reduced rise in O2 pulse
- VAT lower than predicted
What changes on CPET testing are seen in Fontan patients?
- Low-normal CO and O2 pulse at rest
- Lower exercise-related increases: Lower peak VO2, lower peak HR, decreased or flattened O2 pulse, VAT lower than predicted
Why do Fontan patients have lower exercise-related increases in Vo2, HR, O2 pulse and VAT?
- Lower CO and O2 pulse at rest
- Passive perfusion to pulmonary vasculature can’t accommodate higher HR and CO that is needed during peak exercise
What are some common reasons for pediatric stress testing?
- Evaluate specific signs/symptoms that are induced or aggravated by exercise
- Assess or identify abnormal responses to exercise in children with cardiac, pulmonary or other organ disorders (including the presence of myocardial ischemia and arrhythmias)
- Assess efficacy of specific medical or surgical treatments
- Assess functional capacity for recreational, athletic and vocational activities
- Evaluate prognosis, including both baseline and serial testing measurements
- Establish baseline data for institution of cardiac, pulmonary or MSK rehabilitation
What is CPET often indicated for in pediatric patients?
- Assessment of EP abnormalities (long QT, WPW, suppression of ventricular ectopy, other arrhythmias)
- Safety of participation in sports/exercise capacity
- Efficacy of medical/surgical interventions
What are some circumstances when exercise testing should be terminated?
- Inadequate CO: SBP >250mmHg, DBP >125mmHg, fall in SBP >10mmHg from baseline with increasing workload)
- SpO2 <90% or 10 point drop from baseline
- > 2mm flat or down-sloping ST depression
- SVT
- Increasing ventricular ectopy (>3-beat run)
- Development of a BBB or AV block
- Dyspnea
- Angina suggestive of ischemia
- Patient wants to stop
Increases in HR up to what can be expected on exercise testing?
> 200bpm on treadmill
>195bpm on bike
What variables are typically assessed during CPET with gas anaylsis?
- Peak VO2
- Max HR
- O2 pulse (VO2 per heart beat, mL/beat/kg)
- O2 saturation
- BP
- VAT
- End tidal pO2 and pCO2
- Ve/VCO2 slope
- ECG
What is VAT?
Ventilatory anaerobic threshold: VO2 just before the exercise intensity at which pulmonary ventilatory equivalent for O2 increases disproportionately relative to VO2 marked by onset of anaerobic metabolism and buffering of lactic acid
What is Ve/VCO2 slope used for?
To determine efficiency of gas exchange and potential V/Q mismatch when interpreting in conjunction with end-tidal volumes
What are higher risks for doing exercise stress testing?
- Pulmonary HTN
- LQTS
- DCM/RCM with CHF or arrhythmia
- History of hemodynamically unstable arrhythmia
- HCM with symptoms, >mild LVOTO, documented arrhythmia
- Greater than moderate airway obstruction on baseline PFTs
- Marfan + activity related CP in whom a non-cardiac cause of CP is suspected
- Suspicion of myocardial ischemia with exertion
- Routine testing of Marfan
- Unexplained syncope with exercise
What are some lower risks for doing exercise stress testing?
- Symptoms during exercise in an otherwise health child with normal exam/ECG
- Exercise-induced bronchospasm studies in absence of severe resting airway obstruction
- Asymptomatic ventricular ectopy in patients undergoing evaluation for possible LQTS
- Asymptomatic ventricular ectopy in patients with structurally normal hearts
- Patients with unrepaired or residual congenital cardiac lesions who are asymptomatic at rest (L-R shunts- ASD/VSD/PDA/PAPVR, obstructive right heart lesions w/o severe resting obstruction- TS, PS, ToF, obstructive left heart lesions w/o severe resting obstruction- Cor triatriatum, MS, AS, CoA, regurgitant lesions regardless of severity)
- Routine f/u of asymptomatic patients at risk for myocardia ischemia (Kawasaki w/o giant aneurysms or known coronary stenosis, after repair of anomalous LCA, after arterial switch)
- Routine monitoring in transplant patients not experiencing rejection
- Palliated cardiac lesions w/o uncompensated CHF, arrhythmia or extreme cyanosis
- History of hemodynamically stable SVT
- Stable DCM w/o uncompensated CHF or documented arrhythmia
What variables on exercise testing are most useful in determining aerobic/anaerobic functional capacity?
- VO2
- O2 pulse VAT
What does O2 pulse represent?
Volume of O2 taken up by pulmonary blood with each heart beat
What does O2 pulse depend on?
Volume of O2 extraction by peripheral skeletal muscles
How do you calculated O2 pulse?
Divide VO2 by the simultaneously recorded HR (VO2/HR)
*Re-arrange Fick equation where O2 pulse is product of SV and AVO2 difference…. VO2/HR = SV * C(a-v)O2
Immediate increases in O2 pulse in early phases of exercise depends primarily on increases in what?
SV
As the work rate increases, O2 pulse increases primarily because of increasing what?
C(a-v)O2
*Max O2 extraction occurs in tissues at peak exercise, but mixed venous saturation is constant. Thus, more O2 is extracted from each stroke volume of blood during incrementally increased exercise workload
How do O2 pulse and VO2/heartbeat increase with maximum workload?
Hyperbolic fashion (reflected in an increased HR)
What happens to the O2 pulse if a patients stroke volume is reduced?
-O2 pulse (and C(a-v)O2) reach max values at low work rates
O2 pulse is a surrogate marker for what?
Stroke volume
*Patients with compromised ventricular function and limited stoke volume adaptation will have a reduced rise in O2 pulse or flattened O2 pulse during max exercise
O2 pulse and VO2 are measures of what during exercise?
Aerobic capacity
What are 2 peak exercise parameters?
VO2 and O2 pulse
What is a measure of aerobic fitness obtained at submaximal exercise?
VAT (ventilatory anaerobic threshold)
What is the VAT (ventilatory anaerobic threshold) defined by?
VO2 just before the exercise intensity at which the pulmonary equivalent for O2 (VE/VO2- ratio of ventilation to O2 intake) increases while the ventilatory equivalent for CO2 (VE/VCOR- ratio of ventilation to CO2 output) remains constant
What happens at the VAT?
Acid (lactate) production begins due to reliance of anaerobic metabolism as metabolic demands exceed the cardiovascular system’s ability to deliver O2 to exercising muscles
How is VAT expressed?
As a % of peak VO2
Thus VO2 and VAT usually trend in the same direction…patients with impaired cardiac function typically fail to reach their normal % predicted VO2 and have a VAT lower than predicted
What is the 95% lower limit of VAT for adults and children?
Adults: 40%
Children: 44%
What does a VAT that is below the 40% predicted indicate?
Impairment in ability to CV system to increase CO to support hemodynamic demands of exercise
Any cardiovascular condition that impairs what will lower the VAT?
O2 delivery to exercising muscles
What does VAT assess?
Anaerobic capacity
What changes are seen in terms of O2 consumption, peak O2 pulse and VAT in patients with single-ventricle physiology (Fontan), impaired systemic ventricular function or significant AVVR?
Decreased for all 3
What does VACTERL stand for?
- Vertebral anomalies
- Anal atresia
- Cardiac defects
- TE fistula
- Renal anomalies
- Limb abnormalities (radial/non-radial)
Is VACTERL a syndrome?
No- this is an association… no common pathogenic mechanism for occurrence, but defects occur together much more frequently than by chance alone
How many defects must be present to diagnose someone with VACTERL?
At least 3
*VACTERL is a diagnosis of exclusion, so there shouldn’t be any clinical/lab evidence of an alternate diagnosis
What is thought to cause VACTERL?
Developmental field defect during blastogenesis that results in abnormal embryonic mesoderm derivatives
CHD has been reposted in what % of patients with VACTERL?
40-80%
What is the most common cardiac defect in VACTERL patients?
VSD
*Others seen include ASD, PDA, ToF, DORV, AP window, vascular rings
True or False: A single umbilical artery is frequently seen in patients with VACTERL association?
True- this finding should prompt an evaluation of all organ systems for congenital anomalies
CHARGE syndrome?
- Coloboma of eye
- Heart defects
- Atresia choanae
- Retardation of growth
- Genital abnormalities
- Ear anomalies (hearing loss)
What are the most frequent cardiac defects seen in CHARGE syndrome?
ToF, DORV, aortic arch anomalies
A mutation in what gene is seen in many patients with CHARGE syndrome?
CHD7
What is the most common heart-hand syndrome?
Holt-Oram
Holt-Oram syndrome inheitance?
AD
Holt-Oram syndrome?
- Upper-limb skeletal anomalies of preaxial radial ray (triphalangeal thumb to phocomelia)
- CHD (75% cases): ASD and VSD
- Progressive AV conduction delay
TBX5?
Holt-Oram
Complete or partial agenesis of pectoralis major muscle that is variably associated with other thoracic malformations, upper-limb malformations or both?
Poland sequence
*Not usually associated with CHD
True or False: Intelligence and development is usually normal in VACTERL patients?
True
*Overall prognosis depends on type/severity of defects present
What are important parts of the CV exam for the pre-participation CV screening of competitive athletes?
Resting BP/HR, auscultation, femoral pulses
HTN can be diagnosed if a patient has auscultation-confirmed BP readings of what?
At or above 95th percentile for age, sex, height percentiles (>130/80mmHg in children >13 years) on 3 different visits
What should be performed for confirmation of HTN in children and adolescents before they undergo additional testing?
Ambulatory blood pressure monitoring
*More accurate for diagnosis of HTN than clinical BP measurement, can rule-out white-coat HTN and more reproducible than casual/home BP measurements
List BPs for kids greater than or equal to 13 for normal BP, elevated BP, stage 1 HTN and stage 2 HTN
Normal: <120/<80mmHg
Elevated: 120/<80 to 129/<80mmHg
Stage 1: 130/80-139-89mmHg
Stage 2: >140/90
List BPs for kids under 13 for normal BP, elevated BP, stage 1 HTN and stage 2 HTN
Normal: <90th percentile
Elevated: >90th percentile to <95th percentile or 120/80mmHg to <95th percentile (whichever is lower)
Stage 1: >95th percentile to <95 percentile + 12mmHg, or 130/80 to 139/89mmHg (whichever is lower)
Stage 2: >95th percentile +12mmHg or >140/90mmHg (whichever is lower)
What is the purpose of echo in HTN?
- Cardiac target organ damage
- Rule out secondary causes like CoA
When should echo be performed in HTN?
When pharmacologic treatment of HTN is being considered
What exam findings would point against CoA as a cause of HTN?
- Normal femoral pulses
- No upper/lower gradient
What patients would you exclude from competitive sports participation until BP is better controlled?
- Uncontrolled Stage 2
- Evidence of end-organ injury (echo-evident LVH)
What should be reinforced at every encounter for HTN patients?
Lifestyle measures (diet, sleep, aerobic activity)
What should be done for a BP in the elevated range?
Lifestyle medications
Repeat measurement in 6 months
What lab tests are part of the diagnostic evaluation in all patients with HTN?
Screening UA
Chemistry panel
When should patients with HTN get a renal US?
- Kids <6
- Those with abnormal urinalysis findings or renal function
Fever, knee pain/swelling, heart murmur, MR, elevated CRP?
Acute rheumatic fever
What is a delayed, post-infectious sequela of pharyngitis due to group A B-hemolytic strep?
Acute rheumatic fever
How is acute rheumatic fever diagnosed?
Jones criteria
What test can be done as evidence of a recent group A B-hemolytic strep infection when considering acute rheumatic fever?
Anti-streptolysin O titer
Especially when throat culture or rapid strep test is negative
In what geographic regions does acute rheumatic fever remain a significant source of morbidity in youth?
Asia, Pacific Rim, Africa
The incidence of acute rheumatic fever is highest in children between what ages?
5-15
Where is acute rheumatic fever commonly seen?
Populations where strep pharyngitis isn’t commonly treated
What is the major cardiac manifestation of acute rheumatic fever?
Carditis
*Present in more than 1/2 of all initial episodes
What is the most common form of carditis seen in acute rheumatic fever?
Valvulitis- Often new-onset MR
*But aortic valve can also be affected
True or False: Subclinical carditis (echo with MR/AR or both) is sufficient in the diagnostic criteria for acute rheumatic fever?
True- may or may no have murmur
What are other forms of carditis that can occur in acute rheumatic fever besides valvulitis?
- CHF due to myocarditis
- Prolonged PR interval
- Pericardial effusion
- Any combination
Besides the heart, what are the other organ systems affected?
Joins, skin and CNS
What is the classical MSK presentation of acute rheumatic fever?
Migratory polyarthritis of larger joints
- Now monoarticular arthritis qualifies as major criteria in areas where there is mod-high risk for ARF
- Severity can also range from marked arthritis to milder arthralgia
What are the 2 main skin manifestations of acute rheumatic fever?
- Subcutaneous nodules
- Erythema marginatum
- Much less common than carditis/joint involvement
- Very specific for acute rheumatic fever
What is the major neurological abnormality seen in acute rheumatic fever?
Sydenham chorea
What gender is Sydenham chorea with acute rheumatic fever more common in ?
Females
When does Sydenham chorea typically develop in acute rheumatic fever?
After other manifestations have resolved
What is on the differential diagnosis for acute rheumatic fever?
- Septic arthritis
- Juvenile rheumatoid arthritis
- Chikungunya disease
- Lyme disease
- Kawasaki disease
- Viral myocarditis
- Infective endocarditis
- HSP
- SLE
- Sickle cell disease
- Gout
- Leukemia
- Lymphoma
What is included in the treatment of acute rheumatic fever?
- PO or IM benzathine PCN
- Supportive care for carditis
- NSAIDS for fever/joint symptoms
- Bed rest for mod-severe carditis (not based on evidence based data)
True or False: Cardiac surgery during an acute episode of acute rheumatic fever isn’t indicated unless there is uncontrolled heart failure?
True
What is used for long-term prophylaxis in acute rheumatic fever?
-IM PCN every 3-4 weeks through at least age 21 or 10 years after initial episode (longer if patient lives in setting where endemic or with residual heart disease)
True or False: The revised Jones criteria include monoarticular arthritis if the patient is from an area of mod-high risk of developing acute rheumatic fever
True
True or False: Echo can be used to diagnose carditis in acute rheumatic fever, even if auscultation doesn’t reveal a new-onset heart murmur?
True
Absent pulmonary valve syndrome is most commonly associated with what?
ToF
*Occurs in 2.5% of ToF
True or False: Surgery is often elective in absent pulmonary valve?
True- unless patient has respiratory distress or needs mechanical ventilation
What are some methods for pulmonary artery plication in absent pulmonary valve syndrome?
- Valved conduit
- Monocusp valve placement
- Transannular patch + reconstruction of RVOT
*No single method of RVOT reconstruction has been proven to be superior
What are some known risk factors rehospitalization, re-operation and death in ToF absent PV?
- Era of operation
- Prematurity
- Lower weight at operation
- Neonatal repair
- Longer CPB
- Pre-op respiratory distress
Patients with ToF-PA who have pre-operative respiratory distress more commonly have what lung pathology?
Bronchomalacia- Leads to recurrent respiratory disease/hospitalizations (especially up to age 5)
*Increased mortality for patients with pre-op respiratory distress
What rhythm disturbance is common in sleep, especially in younger patients?
Bradyarrhythmia- sinus bradycardia, junctional escape, sinus pauses, send-degree (type 1) AV block
What often causes bradyarrhythmia during sleep?
Vagal
True or False: Most bradyarrhythmia during sleep doesn’t require treatment?
True- most are asymptomatic and do not need treatment
What patients experience bradyarrhythmias during sleep with increased frequency?
Sleep apnea (especially during periods of apnea)
What should be done for a patient with elevated BMI, daytime fatigue, trisomy 21 and vagally mediated pauses during sleep?
Sleep study
True sinus node dysfunction is common after what types of surgery for CHD?
- Fontan
- Atrial switch
- Sinus venosus defect repair
*Seen less frequency after surgery for other types f CHD
What are some possible symptoms seen with sinus node dysfunction?
- Dizziness
- Syncope
- Presyncope
- Altered consciousness
- Chronotropic incompetence
- Exercise intolerance
If necessary, what is the treatment of sinus node dysfunction?
Pacemaker
When is a pacemaker indicated for sinus node dysfunction?
Symptomatic bradycardia- syncope, presyncope confusion thought to be related to cerebral hypoperfusion or chronotropic incompetence
*Fatigue is very non-specific and often multifactorial as a symptom of bradycardia
What are the IIa recommendations for pediatric patients to get a pacemaker in the setting of sinus node dysfunction?
Resting HR <40bpm or pauses greater than 3 seconds (in complex CHD)
What are the IIb recommendations for pediatric patients to get a pacemaker in the setting of sinus node dysfunction?
Resting HR <40bpm or pauses greater than 3 seconds (in biventricular repair of heart disease)
What treatment may improve sleep-related bradyarrhythmia if indicated?
Treatment of sleep apnea
True or False: Patients with sleep-related sinus bradycardia or transient sinus pauses occurring during sleep, permanent pacing shouldn’t be performed unless other indications for pacing are present?
True
An EP study for what can sometimes be helpful to assess sinus node function in a symptomatic patient whose symptoms are difficult to correlate with forms of sinus node dysfunction?
Sinus node recovery time
In the workup of sinus node dysfunction, how can an exercise stress test be helpful?
It can determine chronotropic incompetence
How is flow in pulmonary vasculature impacted in a fetus with HLHS?
- Entire CO goes across MPA
- Quantity of blood flow in pulmonary vasculature likely higher than normal
- Pulmonary venous flow higher than normal
In a fetus with HLHS, what is the path of blood flow that is returning from the pulmonary veins?
-Has to cross the atrial septum from left to right to get to RV, then MPA across ductal arch to body
What is very important in a fetus with HLHS in terms of the path of blood flow?
Having an unrestricted atrial septal communication to allow for decompression of the LA
What happens to a fetus with HLHS and a restrictive atrial septum?
- LA pressure is high (blood can’t get from LA across atrial septum to RA)
- Causes pulmonary venous pressure to be high
- Results in microvascular changes to the pulmonary veins
- Results in the PVR remaining high after birth
- Results in hypoxia and inadequate tissue oxygenation… increase risk of neonatal demise
Neonates with HLHS and what other finding have a particularly poor prognosis?
Restrictive or intact atrial septum
What impact does maternal hyperoxygenation have on a fetus?
- Increased maternal O2 delivery to fetus
- Prompts drop in fetal PVR
How does a lower fetal PVR impact the venous return to the fetal left heart?
Increases it… lower PVR augments pulmonary arterial flow and thus venous return to fetal left heart
What is used as a diagnostic and predictive tool in the assessment of fetuses with HLHS?
Maternal hyperoxygenation… used to identify fetuses with pulmonary vascular beds that aren’t reactive
An infant with HLHS and restrictive atrial septum needs what after birth?
Prompt decompression of atrial septum
*Infants are at high risk of demise after delivery
When using maternal hyperoxygenation in fetuses with HLHS, what is being assessed?
PI in the pulmonary artery via fetal echo
*Used as a means of assessing pulmonary vasoreactivity… then can infer presence of microvascular changes in the pulmonary bed
What is seen on echo during maternal hyperoxygenation testing in fetuses with HLHS and restrictive atrial septa v. normal fetuses and those with HLHS and patent atrial septa?
- No significant change in pulmonary artery PI
- Normal fetuses and those with HLHS/patent atrial septum had alteration in the pulmonary artery PI during maternal hyperoxygenation
What can maternal hyperoxygenation testing in fetuses with HLHS be used to predict?
Need for immediate intervention on the interatrial septum
What are the 3 identifiable waves on Doppler of the pulmonary veins?
- S
- D
- A
What changes are seen in the S/D/A waves of a pulmonary vein in a fetus with HLHS and restrictive atrial septum?
- Accelerated flow during systole (S-wave)
- Accelerated flow during diastole (D-wave)
- Reduced or reversed flow at the time of atrial contractions (A-wave)
What happens to the A-wave on a pulmonary vein doppler in the setting of elevated LA pressure?
A-wave reverses
*Larger A wave reversals indicate more elevated LA pressure (i.e. in a fetus with HLHS and restrictive atrial septum)
Should NO or 100% FiO2 be given to a neonate with HLHS and restrictive atrial septum?
No… would lower PVR and increased pulmonary venous return to LA, but restriction in atrial septum, this will only worsen LA hypertension
What effect does maternal hyperoxygenation normally have on a fetus?
- Increased maternal O2 delivery to the fetus
- Lower fetal PVR
What can be used to assess fetal pulmonary vasoreactivity?
Maternal hyperoxygenation
What happens to the peripheral SVR and CO in septic shock?
Peripheral SVR low
CO high
What results in lactic acidosis in the setting of septic shock?
Impaired O2 extraction in the setting of low SVR, high CO
What is the mixed venous saturation in septic shock?
High- issue is impaired O2 extraction
What type of shock (warm/cold) is seen with poor capillary refill, higher filling pressures, normal/narrow pulse pressure, low mixed venous saturation?
Cold
What is NIRS monitoring helpful for?
- Estimating O2 delivery to various tissue beds
- Noninvasive corollary to invasive diagnostic modalities that monitor CO (mixed venous saturation, thermodilution, etc)
True or False: The absolute value of a NIRS monitor may not always be accurate, but the trend can reflect changes in mixed venous saturation?
True… Trending device
What can falsely lower NIRS monitor readings?
- Jaundice
- Poor skin perfusion
- Malpositioned probes
Why does jaundice cause the NIRS valve to be falsely low?
Bilirubin molecules deposited in the skin can absorb light at a wavelength similar to that emitted by most commercially available NIRS devices (700-850nm)
What could be a potential cause of a significant low saturation on a blood gas?
If the catheter tip was in the coronary sinus
*CS blood has lowest O2 content of any vascular bed due to high O2 extraction in the myocardium
What can air bubbles as a contaminant in a blood gas sample cause?
- Partial pressure of O2 to be falsely high
- Partial pressure of CO2 to be falsely low
What type of shock results in the peripheral SVR being low, CO being high, O2 extraction impaired, lactic acidosis and high mixed venous saturation?
Septic
In what circumstances will patients demonstrate signs of cold shock- poor capillary refill, elevated filling pressures, narrow pulse pressure, low mixed venous saturation?
Low CO state/cardiogenic shock
What is a non-surgical alternative for eligible patients with significant pulmonary regurgitation who require pulmonary valve replacement?
Percutaneous pulmonary valve implantation
What are some complication of percutaneous pulmonary valve implantation?
- Coronary artery compression
- Conduit tear or disruption
- Infective endocarditis
- Stent fracture
True or False: Percutaneous pulmonary valve implantation involves manipulation of the RV infundibulum?
True
In a percutaneous pulmonary valve implantation, the stent placed to ensure a safe landing zone for the valve can protrude into the RVOT… what effect can this have?
-Mechanical irritation and local trauma of the RVOT which may trigger VT
What % of patients experience percutaneous pulmonary valve implantation related VT within 24 hours of implantation?
7.5%
Describe the VT seen in patients following percutaneous pulmonary valve implantation?
- Nonsustained
- Monomorphic
- Rates 120-170
- QRS axis suggests an RVOT origin
Which patients appear to have a greater frequency of percutaneous pulmonary valve implant related VT?
Younger/smaller… may be related to shorter outflow tracts becoming more irritated from the stent
What is the first-line therapy for VT from any cause?
Beta blockers
What medication is used for VT following percutaneous pulmonary valve implant?
Beta blockers
True or False: VT following percutaneous pulmonary valve implant is felt to be a transient phenomenon and patients can often be weaned off beta-blockers at a later time without arrhythmia recurrence?
True
Short runs of VT following percutaneous pulmonary valve implant could be observed without therapy?
True pending situation… often use beta blockers
What medication is used for polymorphic VT (torsades de pointes)?
Magnesium
*Or for ventricular ectopy in the context of hypomagnesemia
True or False: The need for surgical explanation for percutaneous pulmonary valve implantation related VT is rare?
True- this VT typically resolves with time (especially in the periprocedural period)
True or False: Percutaneous pulmonary valve implantation may be associated with transient ventricular tachycardia in the acute periprocedural period, especially in patients of smaller size?
True
True or False: Percutaneous pulmonary valve implantation-related ventricular tachycardia has a favorable long-term prognosis?
True
What are some complications of percutaneous pulmonary valve implantation?
- Coronary artery compression
- Conduit tear or disruption
- Infective endocarditis
- Stent fracture
Short palpebral fissures, smooth philtrum, thin upper lip, hockey stick configuration of upper palmar crease, “railroad track” ears?
Fetal alcohol syndrome
What 2 procedures might you see the LeCompte pulmonary arteries in?
- ASO in d-TGA
- Following repair of ToF/absent PV
Patients with fetal alcohol syndrome have an increased risk of what form of CHD?
d-TGA
- Overall, current data don’t support increased risk of CHD with fetal ethanol exposure
- FAS + CHD more likely to have d-TGA v. other lesions
In utero exposure to what is a risk factor for 22q11.2 gene deletion (DiGeorge)?
Retinoic acids (isotretinoin)
There is significant overlap in the facial features associated with 22q11.2 and what?
Fetal alcohol syndrome
What type of CHD is seen in 22q11.2 deletion?
Conotruncal defects
Large fontanels, prominent glabella, marked periorbital and eyelid edema, low nasal bridge with transverse crease, short nose and lateral soft tissue nasal buildup can be seen following in utero exposure to what?
Cocaine
What 3 things are fetal cocaine exposure associated with?
- Prenatal placental infarction
- Postnatal ectopy
- Rhythm distrubances
True or False: Caffeine hasn’t been shown to be associated with structural heart defects?
True
There is an association between fetal alcohol syndrome and what form of CHD?
D-TGA
*Cause and effect between the two conditions is unknown
What is the definition of transposition physiology?
PA sat > Ao sat
What is the most common congenital heart anomaly to present at birth with immediate cyanosis that is unresponsive or minimally responsive to O2?
d-TGA
True or False: In many infants with d-TGA, ductal mixing is inadequate to support systemic O2 delivery>
True
What is often needed in d-TGA to deliver more oxygenated blood to the RV and ultimately the systemic circulation?
Adequate atrial level shunt
What is the best initial intervention to stabilize a neonate with d-TGA and improve their oxygenation?
Immediate BAS
What should be done in the interim while awaiting a BAS for a neonate with d-TGA?
- Improve oxygenation
- Reduce metabolic/oxygen demand
*Things like intubation, sedation, etc
What does high PVR seen in the initial perinatal period do to shunting/saturations in a neonate with d-TGA?
- R-L shunting (LV-Pa-Ao) at the ductal level
- Explains higher lower-extremity saturations
How does an infant with ductal-dependent systemic blood flow (like in critical aortic obstruction) present?
- Not symptomatic immediately after birth
- Develop shock/diminished lower-extremity perfusion as PDA closes over time
How does an infant with obstructed pulmonary venous return present?
- Severe refractory cyanosis
- Significant respiratory distress
- Surgical emergency (no cath interventions… unlikely to address obstruction and only delays definitive therapy)
When do infants with ductal-dependent pulmonary blood flow (critical PS or PA) develop hypoxemia?
When the ductus begins to close
What is the most common congenital heart anomaly to present with immediate and refractory cyanosis at birth?
d-TGA
What is needed for patients with d-TGA, severe hypoxemia and inadequate atrial level mixing initially to stabilize and mprove oxygenation?
BAS
What is associated with a loss of dystrophin leading to skeletal myopathy, respiratory disease and progressive cardiomyopathy?
Duchenne muscular dystrophy (DMD)
What are the leading causes of morbidity and mortality in patients with DMD?
Cardiomyopathy and arrhythmia
*Used to be respiratory, but improvements in respiratory care have shifted things
When should a boy with DMD be referred to cardiology?
At time of diagnosis
When do most boys with DMD exhibit evidence of heart disease?
Between 10-14
What is the goal of early referral to cardiology for boys with DMD?
- Detect heart disease early
- Institute interventions that slow the progression of cardiomyopathy, extend life and improve quality of life
What is first-line therapy in children with systolic dysfunction (including those with DMD)?
ACEi
True or False: Cardiac therapies can be useful before the onset of systolic dysfunction in various forms of cardiomyopathies/heart failure?
True
What is a helpful modality to detect fibrosis before changes in traditionally measured indices (like LVEF) are evident?
CMR
*Fibrosis on CMR correlates with histopathologic studies that reveal subepicardial myocardial fibrosis, degeneration and fatty infiltration
What finding on CMR is consistent with myocardial fibrosis?
Hyperenhancement/delayed enhancement
When is initiation of ACEi therapy indicated in boys with DMD?
- When heart failure symptoms become evident
- When imaging shows abnormalities such as depressed LVEF, abnormal chamber dimensions or presence of myocardial fibrosis
Carvedilol is used for heart failure patients in what cirucmstances?
- Symptoms of heart failure
- Evidence of systolic dysfunction
True or False: The role of carvedilol in patients with preserved systolic function remains unclear
True
When are digoxin and furosemide used in heart failure?
When patients develop specific symptoms- systolic dysfunction (digoxin), volume overload/pulmonary edema (furosemide)
When should ACEi be started in boys with DMD?
Slightly different recommendations…
- All boys by age 10, can consider before 10
- Can consider before onset of reduced EF before age 9
What are the leading causes of morbidity and mortality in DMD?
Cardiomyopathy and associated arrhythmias
What is helpful to detect fibrosis in boys with muscular dystrophy?
CMR
What is the most common form of cor triatriatum sinister?
Pulmonary veins drain to chamber (pulmonary venous chamber) with a restrictive communication to the LA
How does cor triatriatum sinister result in pulmonary arterial HTN?
-Small communication between pulmonary venous chamber and LA results in high pulmonary venous pressure which leads to pulmonary arterial HTN
When do patients with cor triatriatum present?
Early in life
What are possible symptoms of cor triatriatum?
- Shortness of breath
- Exercise intolerance
What are the possible cardiac exam findings associated with cor triatriatum?
- Loud pulmonary component of S2 (pulmonary HTN)
- Soft systolic murmur loudest along LSB due to TR
What can be seen on CXR in cor triatriatum?
- Pulmonary venous congestion
- Upper pulmonary veins engorged (“staghorn” sign)
- Kerley B lines
- Fine reticular pattern
What are the typical ECG findings in cor triatriatum?
- RAE
- RVH
- Possible RAD
Describe the classic form of cor triatriatum?
- All pulmonary veins drain to pulmonary venous chamber
- Membrane-like structure separates pulmonary veins from true LA
- Opening in membrane-like structure is sole communication with true LA
- LA appendage often distal to obstruction
What are some possible variants of cor triatriatum besides pulmonary veins to pulmonary venous chamber with membrane-like structure separating pulmonary veins from true LA with an opening in the membrane-like structure being the sole communication with the true LA?
- Pulmonary venous chamber can have 2 means of egress (in addition to restrictive communication, there is a connection directly to RA or via an anomalous pulmonary venous connection)
- Lack direct communication with the LA (pulmonary venous chamber is decompressed by direct communication with the RA or an anomalous pulmonary connection)
- Both require presence of an atrial level shunt to allow for flow into the LA
- Pulmonary veins from 1 lung lack unobstructed communication with LA… affected veins may drain to LA or RA and unaffected veins drain normally or anomalously
Cor triatriatum dexter is felt to be the result of persistence of what?
Right valve of the sinus venosus
What can cor triatriatum dexter result in?
Cyanosis due to R-L shunting… if membrane has restrictive opening and venous return from SVC is proximal to the obstruction, it can result in a R-L atrial shunt and cyanosis
What is the classic form of cor triatriatum?
When all 4 pulmonary veins connect to a pulmonary venous chamber with a single outlet through a membrane-like structure to the LA
How does cor triatriatum usually present?
Early in life with symptoms and signs of pulmonary venous congestion
What is the gene deletion in Williams syndrome?
7q11.23
What results from a mutation in the elastin gene on chromosome 7?
Williams
“Elfin” facies, cardiac defects (supravalvar AS and/or PS, developmental and growth delay, ebullient personality, strength in language skills in the setting of deficits in visuospatial tasks, hypercalcemia, digestive problems, urinary problems, abnormalities of connective tissue?
Williams
What CHD should all kids with Williams syndrome be screened for?
Supravalvar AS or PS
What needs to be specifically imaged in a child with Williams syndrome and supravalvar AS?
Coronary origins… may be partially obstructed by a membrane related to the stenosis
*May be hard to see by echo and require CTA or cath if there is a suspicion of coronary artery narrowing
Children with supravalvar AS carry a very high risk for what?
Anesthesia… should have a cardiac anesthesiologist prior to general anesthesia or sedation for any procedure
What is thought to cause increased risk in patients with supravalvar aortic stenosis undergoing anesthesia?
- Drop in SVR from sedation/anesthesia increases LV-Ao gradient
- Potentially compromises coronary artery perfusion
True or False: Even in the absence of definitive supravalvar AS in Williams, there can still be coronary ostial obstruction?
True
If there are no concerning symptoms, that is the test of choice for coronary artery anatomy in a patient with Williams syndrome?
Echo
What are some echo findings that would point away from myocarditis as the cause of significantly elevated troponin levels?
- Bright papillary muscles
- Segmental wall motion abnormalities
*Raise concern for a focal ischemic process typically related to coronary insufficiency
What needs to be ruled out in any child, regardless of age of presentation, with new-onset severe ventricular dysfunction?
ALCAPA
What is the gold standard test for examining coronary arteries?
Cath including aortic root injection and selective coronary angiography
True or False: CMR can be helpful to diagnose coronary artery anomalies, but doesn’t provide the same level of detail that a cath does?
True
There needs to be a high index of suspicion regarding what in patients with Williams syndrome (even if they don’t have significant supravalvar AS)?
Coronary artery stenosis
What causes a WW pattern seen on ECG?
- Presence of an accessory bypass tract (accessory pathway) that bypasses AV conduction over the AV node and results in preexcitation of the ventricle
- This creates the delta wave seen on ECG
What is the typical presentation of WPW?
Palpitations or presyncope caused by AVRT
How can WPW cause SCD?
If there is rapid conduction of a-fib over the accessory pathway resulting in ventricular fibrillation
True or False: Catheter ablation is capable of eliminating the risk of SCD in asymptomatic WPW patients with success rates as high as 95%?
True
All asymptomatic patients with WPW need to undergo risk stratification to determine what?
Individual risk of development of ventricular fibrillation/lethal cardiac arrhythmia
How is risk stratification typically done for asymptomatic patients with WPW?
Exercise stress test (once old enough around age 8) to assess for sudden, abrupt disappearance of the preexcitation at physiological HR
What is a surrogate for poor anterograde conduction of the accessory pathway and thus lower risk of SCD in patients with WPW?
Exercise stress test with sudden, abrupt disappearance of the preexcitation at physiological HR
When is an EP study indicated to risk stratify WPW?
If there is an inability to clearly demonstrate abrupt complete loss of preexcitation during exercise stress testing
What does an EP study measure to help risk stratify asymptomatic patients with WPW?
Shortest preexcited RR interval between two consecutive pre-excited beats (SPERRI)
A SPERRI value (shortest pre-excited RR interval between 2 consecutive pre-excited beats) less than what during an EP study for asymptomatic WPW identifies a subset of patients with an increased risk of SCD?
<250msec
What should be done for patients with asymptomatic WPW and a A SPERRI value (shortest pre-excited RR interval between 2 consecutive pre-excited beats) less than 250msec?
Catheter ablation to eliminate the risk of SCD
On average, ADHD medications increase HR by how much?
1-2bpm
On average, ADHD medications increase SBP by how much?
3-4mmHg
True or False: Patients with WPW may be prescribed ADHD medications as long as they are closely observed?
True- there is no definitive evidence to support an associated increased risk of cardiac events, nor are there any reports of SCD in patients with WPW receiving ADHD medications
True or False: The risk of SCD in WPW patients is low?
True… but no non-existent (even in asymptomatic patients)
True or False: All asymptomatic patients with WPW need to undergo stratification for risk of SCD?
True
Name 2 risk factors for pulmonary vein stenosis?
- Prematurity
- Bronchopulmonary dysplasia
What characterizes pulmonary vein stenosis?
Fibromyxoid intimal proliferation of the large (extrapulmonary) pulmonary veins)
Pulmonary vein stenosis is most commonly associated with what?
Surgically repaired TAPVR
*Can be seen in other types of CHD as well as structurally normal hearts
Describe the pathophysiology of pulmonary hemorrhage caused by pediatric pulmonary vein stenosis
- Significant pulmonary congestion results in the capillaries dilating and leaking blood into the alveolar spaces
- Leads to an increase in hemosiderin-laden macrophages due to breakdown of RBCs in the macrophage cytoplasm
Which has a higher incidence in pulmonary vein stenosis, increase in hemosiderin-laden macrophages in alveolar spaces or fibromyxoid intimal proliferation of the large extrapulmonary pulmonary veins?
Fibromyxoid intimal proliferation of the large extrapulmonary pulmonary veins
True or False: Pulmonary arterial and arteriolar changes are present in most patients with significant pulmonary hypertension?
True- due to hypertensive remodeling
What type of arterial hypertrophy is very common in patients with significant pulmonary hypertension?
Medial
Besides medial hypertrophy, what other changes are seen in the pulmonary arteries/arterioles with significant pulmonary hypertension?
- Hypertrophy accompanied by arterial intimal fibrosis (25% of patients)
- Plexiform change (<5% cases)
- Angiomatoid change with fibrinoid necrosis (<5% cases)
What are some of the reported histological findings in pulmonary artery hypertension?
- Muscularization of pulmonary arterioles
- Foreign-body giant-cell reactions within or immediately adjacent to vessels (presumably due to prior embolization of foreign material introduced via prior peripheral venous instrumentation)
- Lymphangiectasia
What is characterized by a fibromyxoid intimal proliferation of the large (extrapulmonary) pulmonary veins?
Pulmonary vein stenosis
In what disease process can you see alveolar hemosiderin-laden intra-alveolar macrophages?
Pulmonary hypertension
What is double-chambered RV?
- Malformation in which the RV is divided by aberrant hypertrophied muscle bundles into a proximal high-pressure chamber consisting of the RV sinus and a distal low-pressure chamber consisting of the infundibulum
- Anomalous muscle bundles attach inferiorly to the ventricular septum below the tricuspid septal leaflet insertion and anteriorly to the RV wall
What is thought to cause double-chambered RV from an embryology standpoint?
- Incomplete incorporation of the bulbus cordis into the primitive RV
- Abnormal expansion of the trabeculation in the primitive RV
A membranous VSD is seen what % of cases of double chambered RV?
80-90%
True or False: RV obstruction may develop even after an associated VSD has spontaneously closed or been surgically repaired?
True
True or False: Discrete subaortic stenosis and pulmonary stenosis can be seen in patients with double chambered RV?
True
How does double-chambered RV usually present?
- Often early childhood with an asymptomatic child referred due to murmur
- Can also present in adulthood (non-specific symptoms like exertional chest pain, exercise intolerance, syncope, cyanosis)
True or False: RV obstruction in double chambered right ventricle is usually progressive?
True
What does isolated double chambered RV present similarly to?
Pulmonary valve stenosis
What 2 things does presentation of double chambered RV with an associated VSD depend on?
- Size of VSD
- Severity of RV obstruction
- Mild-mod RV obstruction = VSD with pulmonary overcirculation
- As perimembranous VSD connects to proximal high-pressure RV body, severe RV obstruction may result in R-L shunting and cyanosis
Describe the murmur often heard in double chambered RV?
- Loud, harsh, pansystolic, crescendo-decrescendo
- Often associated with a thrill at the mid-left sternal border
What is “low type” double-chambered RV?
Obstructing muscle bundles oriented obliquely in RV body
What is “high type” double-chambered RV?
Obstructing muscle bundles oriented horizontally just below the infundibulum
True or False: In double chambered RV, the infundibulum is inherently abnormal?
False
*The normal infundibulum is useful in differentiating DCRV from ToF (where infundibulum is hypoplastic)
True or False: Cath is required in the workup for double chambered RV?
False- usually can be diagnosed by TTE, TEE or MRI… cath only used in select cases when noninvasive imaging is inconclusive
When should double chambered RV be repaired?
- If RV pressure gradient is >40mmHg
- Any associated symptoms
What is done during repair of double chambered RV?
- Resection of obstructing RV muscle bundles
- Closure of any associated VSD
True or False: Overall prognosis of double chambered RV is excellent after surgical repair with rare recurrence of RV obstruction?
True
Is the RVSP estimate from TR jet high or low in patients with double chamber RV?
High- reflects the increased pressure in the proximal RV chamber… infundibular and PA pressures are usually normal
What lesions is characterized by obstruction in the RV body by hypertrophied anomalous RV muscle bundles?
Double-chambered RV
What is double-chambered RV usually associated with?
Membranous VSDs
*Less commonly subaortic membrane
What are the components of workup in an infant with heart failure/systolic dysfunction?
Patient history, family history, imaging
What is included in the differential diagnosis for an infant with systolic dysfunction leading to heart failure?
- Myocarditis
- Tachyarrhythmia-induced cardiomyopathy
- Metabolic concerns
- Familial cardiomyopathies
- CHD (LV obstructive lesions, ALVAPA, primary mitral valve pathology)
What is LVNC defined by?
Thin compacted myocardial layer and a thickened endocardial layer with prominent myocardial trabeculations and deep recesses
What are the Jenni criteria for LVNC?
End systolic endocardial-to-myocardial ratio of 2:1 via echo
What are the Petersen criteria for LVNC?
End diastolic ratio of 2.3:1 via MRI
True or False: LVNC may be an isolated finding or associated with other forms of cardiomyopathy, CHD or genetic syndromes?
True
True or False: LVNC often presents as a mixed cardiomyopathy in which the phenotype is a combination of hypertrophic, dilated or restrictive cardiomyopathy?
True
What are the most common forms of CHD associated with LVNC?
- PS
- Septal defect
- Ebstein
*But can be seen with any form of CHD
What is the most prominent genetic syndrome associated with LVNC?
Barth
Skeletal myopathy, neutropenia, prepubertal growth delay and cardiomyopathy?
Barth
What category of genetic conditions does Barth fall into?
Mitochondrial myopathy
What type of cardiomyopathy can be seen in Barth?
LVNC
True or False: Studies have shown that children with LVNC w/o CHD have significant morbidity and mortality?
True- risk highest in infants with systolic dysfunction and ventricular tachycardia
- Up to 60% of patients who have undergone transplant for primary LVNC diagnosis are children
- In adults, there has been no difference shown in outcomes of incidentally diagnosed LVNC…? whether isolated LVNC with preserved systolic/diastolic function represents cardiomyopathy or phenotypic normal variant
True or False: LVNC can be seen with normal systolic and diastolic function on screening echocardiogram within pediatrics, but significance and expected outcomes remain unclear?
True
What is the next best intervention for an infant with tricuspid atresia, moderate VSD, moderate PS, normal branch PAs and no ductus with acceptable saturations and no evidence of overcirculation?
Bidirectional Glenn
In balanced tricupid atresia, what is the effect of the functionally single ventricle ejecting to both the systemic and pulmonary vascular beds?
Volume load on ventricle…. with time, will result in ventricular dilation/dysfunction
What is the benefit of a Glenn in a patients with tricuspid atresia, VSD and balanced circulation?
Relives the volume load on the single ventricle while maintaining adequate systemic O2 delivery
*Result is a ventricular workload similar to that of the systemic ventricle in normal (biventricular) circulation
What is a key feature of doing a bidirectional Glenn in the setting of single-ventricle physiology with balanced circulation (like tricuspid atresia w/ VSD)?
Allows time for ventricle to remodel before Fontan
What is the most common complication after a bidirectional Glenn procedure?
Phrenic nerve paralysis
*Can also see pleural effusion, prolonged mechanical ventilation (>7 days), need for reintubation, reoperation for bleeding, cardiac arrest, chylothorax, need for post-op ECMO
What procedure offloads volume from a single ventricle?
Glenn
The initial intervention for tricuspid atresia is dependent on what?
Relative amounts of pulmonary/systemic blood flow
- Too hypoxia- Shunt
- Overcirculated- PA band
- Just right- Glenn (when older)
How does fetal echo assess arrhythmia?
Measures the mechanical or flow-related consequences of the arrhythmia
*Chronology/temporal relationship of atrial and ventricular contractions allows one to infer the electrical activation of the heart and mechanism of arrhythmia
What is done to assess for rhythm issues during fetal echo?
- M-mode or pulse-wave Doppler measurements
- Sample volume encompasses both atrial and ventricular tissue
- Gives insight into rate/timing of atrial/ventricular mechanical events (occur shortly after their respective electrical depolarization
What is assessed on M-mode or Doppler during fetal echo to diagnose rhythm abnormalities?
Regularity and rate of atrial-atrial events, ventricular-ventricular events, and relation between atrial and ventricular beats
How should pulse-wave Doppler be aligned for rhythm assessment during fetal echo?
- Inflow-outflow Doppler
- Sample volume placed at inflow portion of LV (beneath level of MV annulus)
- Includes LVOT (w/ or w/o AoV)
What are the 3 waveforms that should be seen on Doppler assessment of fetal heart rhythm during fetal echo?
- Normal inflow has 2 waveforms:
- First is early filling phase of diastole (occurs after opening of AV valve and corresponds to passive, rapid rush of blood from atrium to ventricle)- E wave
- Second is atrial contraction (active filling) which correlates with flow from atrial contraction- A wave
-Outflow is prograde flow across the aortic valve which correlates with ventricular systole (V)
How should the M-mode cursor be aligned for assessment of fetal heart rhythm during fetal echo?
Traverse the most mobile region of the atria and ventricles (will optimally display muscle contraction)
*Need a reference 2D image above M-mode to orient which chamber wall is up and which is down
What does M-mode allow recording of during fetal echo?
Sequence and time relationship of atrial and ventricular systolic wall movements
Why is the volume of blood ejected with a PVC less than normal?
- PVC occurs without atrial activity
- Results in ejection of blood without benefit of having augmented filling through atrial contraction
- Thus volume of blood ejected is less than normal
Why does a beat following a PVC have increased peak velocity and higher VTI?
After a PVC, there is increased time for ventricular filling… so beat subsequent to the PVC may have augmented flow with increased peak velocity and higher VTI
True or False: PVCs may not reset the sinus node like a premature atrial contraction (so atrial activity continues in a regular manner)?
True
What is an important marker of distinguishing a premature contraction as being ventricular in origin?
Regularity of atrial activity
What % of pregnancies manifest a fetal disturbance in cardiac rhythm?
1-3%
What is the most common type of fetal rhythm disturbance?
Transient atrial ectopy (>90%)
*PACs are 10-fold more common than PVCs
Fetal PVCs can occur secondary to what things?
- Myocarditis
- Cardiomyopathy
- Cardiac tumors
- Ventricular diverticulum
- Long QT syndrome
What is the risk of fetal ventricular tachycardia?
Unknown
True or False: Without associated conditions and when isolated, PVCs are thought to be benign?
True
What is the inutero management of fetal PVCs?
Observation- weekly fetal HR measurement until arrhythmia resolves
- Fetal echo at less frequent intervals (monthly) is reasonable to ensure continued fetal well-being and reassess for secondary causes
- If fetal ventricular ectopy doesn’t resolve, a post-natal cardiac assessment is warranted
What happens during a hypercyanotic spell?
- Increase in dynamic outflow obstruction at the subpulmonary valvar level
- Results in an abrupt change in shunt physiology with increased R-L shunting across the VSD
What are some possible scenarios that could precipitate a hypercyanotic spell?
- Acute viral process
- Dehydration
- Systemic vasodilation (ex. anesthesia)
What is one of the first-line therapies for a hypercyanotic spell, especially in the setting of dehydration?
Fluid bolus
How does a fluid bolus help in the setting of a hypercyanotic spell?
- Increase preload/filling in diastole and expand the obstructed area below the pulmonary valve
- Allows more effective pulmonary blood flow
What are some measures that can be used to manage a hypercyanotic spell?
- Volume expansion (increase preload and filling in diastole)
- Reduce catecholamine release
- Increase SVR to reduce R-L shunting (knee-chest position)
True or False: The improvement in a hypercyanotic spell seen with knee-chest position is transient?
True… may make the infant more agitated too
Why don’t pulmonary vasodilators (like iNO) help with a hypercyanotic spell?
- Work at the level of the pulmonary arteriolar bed
- Lead to vasodilation distal to the subvalvar obstruction
- Unlikely to have a profound impact on the pulmonary blood flow
True or False: O2 can be used as supportive care for an infant with viral respiratory symptoms and hypercyanotic spells, but it should be accompanied by other therapies because it has limited benefit in isolation?
True
Why are B-agonists like epinephrine or dopamine contraindicated in a hypercyanotic spell?
May cause tachycardia or increased contractility at the level of the heart which reduces diastolic filling time and worsens obstruction at the infundibulum
What are the 2 classes of CCB?
- Dihydropyridine
- Nondihhydropyridine
What type of CCB is nifedipine?
Dihydropyridine
What type of CCB is verapamil?
Nondihydropyridine
True or False: CCB can be helpful in the management of a hypercyanotic spell?
False- cause vasodilation and thus contraindicated
What class of medications are generally not indicated in infants and can precipitate CV collapse in young infants?
CCB
List some options in management of a hypercyanotic spell?
- Knee-chest
- Volume expansion
- Sedation/analgesia
- B-blocker
- A-agonist
- ECMO
- Emergent surgical shunt
What does an increased PaCO2 to end-tidal CO2 difference suggest?
Increased R-L shunt (decreased pulmonary blood flow)
In a patients with a shunt, what would a DBP higher than expected raise concern for?
Compromise of flow in shunt (diastolic normally low due to run off into the shunt)
What is validated as a tool to assess adequacy of surgical repair at the time of discharge based on echo evaluation of residual cardiac lesions?
Technical performance score
What are the rankings in the technical performance score?
- Class 1: Optimal
- Class 2: Minor residual lesion
- Class 3: Major residual lesion
The technical performance score is an independent predictor of what?
Neurodevelopmental outcomes
*Patients with class 3 lesions have significantly lower Bayley cognitive scores
Class 3 (major residual lesions) on the technical performance score is associated with what?
- Poor neurodevelopmental outcomes
- Increased resource utilization (longer ventilator use and increased length of stay)
- Higher mortality
True or False: Residual cardia lesions after surgery, their severity and how quickly they are resolved are some of the most important factors in short-term and long-term outcomes of patients with CHD?
True
True or False: Anesthesia ventilators are commonly less efficient at oxygenation and ventilation as compared to ventilators found in most ICUs?
True- moving someone from an anesthesia vent to conventional vent may be helpful in the setting of lung disease or poor lung compliance to improve hypoxia
True or False: Residual cardiac lesions after corrective or palliative surgery for CHD are a major cause of morbidity and increased resource utilization?
True
True or False: Patients discharged after cardiac surgery with a technical performance score of class 3 (major residual lesion) are at increased risk for worse neurodevelopmental outcomes and mortality
True
When should significant residual cardiac lesions be corrected for optimal outcomes?
At index surgical procedure
What are some physical exam findings you would expect in an infant with an AP window?
- Tachypnea due to chronic L-R shunting (AscAo-PA)
- Prominent pulses
- Increased pulse pressure
- No murmur (due to elevated PA pressure
Describe an AP window as seen by echo?
- Communication between ascending aorta and adjacent MPA in the presence of 2 separate aortic and pulmonary valves
- Deficient wall leads to unrestrictive shunting between the aorta and PA
What causes an AP window?
Developmental defect in the conotruncal septum separating the aorta and PA
True or False: AP widow could be missed on fetal imaging and during infancy?
True
*Often respiratory symptoms without an overt heart murmur
What are some secondary signs of AP window by echo?
- Left sided heart dilation
- Dilation of the pulmonary arteries
- Retrograde flow in the aortic arch
- Elevated PA pressure (caused by unrestrictive communication between aorta and PA)
*Any of these should prompt evaluation for an AP window
What are the 3 types of AP windows?
1- Proximal defect occurring just above the sinus of Valsalva (45%)
2- Distal defect in the more superior ascending aorta (45%)
3- Large defect between most of ascending aorta with the PA (10%)
What % of AP windows occur as an isolated defect in an otherwise healthy infant?
50-75%
Although more common to occur as an isolated defect, AP windows can be seen in association with what other forms of CHD?
- ToF
- CoA
- IAA
- VSD
True or False: Unlike other conal truncal abnormalities, isolated AP window isn’t typically associated with DiGeorge syndrome or other known genetic abnormalities?
True
What do the symptoms of an AP window depend on?
- Size of defect
- Whether PVR has remained elevated in the presence of large defects with elevated PA pressure
What would be the expected symptoms in cases of elevated PVR with a large AP window?
Patient may be asymptomatic and thus AP window not diagnosed
*Sometimes AP window may not be diagnosed until adulthood and irreversible pulmonary vascular changes have occurred
How is AP window repaired in an infant?
-Patch to separate deficient wall between Ao and PA trunk
What needs to be specifically imaged/confirmed prior to repair of an AP window?
-Coronaries
- An AP window can be associated with anomalous origin of the coronary (usually right) from PA trunk
- Need to determine coronary anatomy to prevent coronary injury or incorporation of the coronary to the pulmonary side of the circulation
What is the prognosis following repair of AP window?
- If early surgical repair- excellent
- Delayed diagnosis, can be problematic if irreversible pulmonary HTN has developed
How does AP window most commonly present?
Isolated defect in young infant with tachypnea, mild respiratory distress and little (if any) murmur
What might delay diagnosis of an AP window?
If there is elevated PVR which leads to less pulmonary overcirculation and fewer respiratory symptoms
What is the differential diagnosis of SVT?
- AVNRT
- AVRT
- JET
- Atrial tachycardia
During SVT, if the cycle length shortens with resolution of a LBBB, what does that indicated?
AVRT using a left sided accessory pathway
- Shortening of cycle w/o LBBB proves that the LBB is part of the circuit causing SVT
- When LBB is blocked or slowed, the cycle length (VA time) is also slowed
- Thus it has to be AVRT
Which type of re-entrant tachycardia (AVRT or AVNRT) can occur with 2:1 atrial to ventricular actiation?
AVNRT
On a surface ECG, what type of SVT does AV or VA block rule out?
AVRT
*Atria and ventricle are both integral parts of circuit
A second-degree AV block suggests what type of SVT?
Atrial tachycardia
*AVNRT can occasionally have 2nd degree AV block too
What type of SVT is suggested by any degree of VA block?
JET in narrow complex tachycardia
*Rarely AVNRT can do this too
True or False: When there is 1:1 conduction of SVT, discerning the exact mechanism is often impossible based on surface ECG alone
True
A VA time < _ msec suggest AVNRT as the cause of SVT?
70
*Hard to measure accurately outside of EP lab
Slower tachycardia rates (<180bpm) suggest what types of SVT?
- AVNRT
- Atrial tachycardia
- Slowly conducting accessory pathway
Termination with an atrial event strong suggests against what type of tachycardia?
Atrial tachycardia
When resolution of a BBB coincides with shortening of the VA time and cycle length during SVT, what is confirmed?
AVRT via an accessory pathway ipsilateral to the site of BBB
AV or VA block without terminating tachycardia rules out what type of SVT?
AVRT
Describe PVCs which originate from the RVOT
LBBB morphology
Inferior axis (+ in inferior leads (II, III, aVF)
PVC transition of R>S occurs in V3 or V4 in precordial leads
What are the most common types of ventricular arrhythmias (PVC and VT) in patients with structurally normal hearts?
Ones that originate from the RVOT
At what PVC burden does the risk for developing PVC-induced cardiomyopathy being?
10-20%
What are some options for management of PVCs?
- Observation (is structurally normal heart with normal function)
- Medication or ablation of focus causing tachycardia (if dysfunction, ventricular tachycardia or symptoms)
True or False: In tachycardia-induced cardiomyopathy, function should recover once rhythm is controlled?
True
What type of bundle branch block morphology do PVCs from the LV have?
RBBB
Describe the ECG for a verapamil-sensitive left posterior fascicular VT (Belhassen or fascicular VT)?
- RBBB morphology
- Superior axis (negative in inferior leads)
What causes the tachycardia seen in verapamil sensitive VT?
Re-entry circuit near left posterior fascicle
Belhassen or fascicular VT is responsive to what medication?
Verapamil
What type of PVCs have a LBBB morphology and inferior axis?
Those from RVOT
What type of VT has a RBBB morphology and superior axis?
Verapail sensitive VT (Belhassen)
Where does verapamil sensitive VT (Belhassen) originate from?
Left posterior fascicle
True or False: PVC induced cardiomyopathy will likely recover with control/elimination of the ventricular arrhythmia
True
Sinus tachycardia with a wide QRS complex with LBBB morphology?
Flecainide toxicity (what the widening of the QRS is most consistent with)
What type of anti-arrhythmic if Flecainide?
Class 1C
What channels does Flecainide affect?
Na
What type of anti-arrhythmic inhibit the fast Na channel, causing rate-dependent slowing of phase 0 in the AP?
Class 1c
What is flecainide used for in pediatric patients?
SVT and VT
Which patients should you be cautious prescribing flecainide to?
- CAD
- Complex CHD
- Cardiomyopathy
*Some studies have shown increased mortality
How should flecainide be initiated?
- In the hospital
- Rhythm monitoring (potential for pro-arrhythmia)
- ECGs to assess QRS widening
- Flecainide levels
What is seen in the setting of flecainide toxicity?
- Significant QRS widening
- Arrhythmias
- Hemodynamic compromise
What is the treatment for flecainide toxicity?
- NaBicarb
- Administration of IV fat emulsion
*With significant hemodynamic compromise, may need ECMO
What should be the cardiovascular symptoms associated with propranolol overdose?
- Bradycardia
- Hypotension
- Hypoglycemia
What should be the cardiovascular symptoms associated with verapamil overdose?
- Bradycardia
- Hypotension
What class of anti-arrhythmic is propranolol?
Class II
What class of anti-arrhythmic is verapamil?
Class IV
Which antiarrhythmic is class 3 and affects K channels and prolongs repolarization?
Sotalol
How does sotalol toxicity present?
- Bradycardia
- QTc prolongation
- Eventual torsades de pointes
Which commonly used antiarrhythmic is class 1c affecting Na channels during phase 0?
Flecainide
How does flecainide toxicity manifest?
QRS widening
What class antiarrhythmic is sotalol?
III
How do class III antiarrhythmics work?
Prolong repolarization
How does sotalol toxicity manifest?
Prolongation of the QTc
Why might an older patient with a significant CoA have a smaller pressure gradient than expected?
Development of significant collateral flow
True or False: The arm-leg BP gradient typically correlates with the transcatheter gradient in CoA?
True
*Unlikely to get a higher gradient via cath, especially with patient under anesthesia
A transcatheter gradient > what is an indication for stent placement to treat native CoA
> 20mmHg
Class IIa recommendation, level of evidence B
In the presence of an arch gradient <20mmHg, what finding in addition to anatomic findings of arch narrowing would be an indication for stent placement?
Systemic HTN (w/ arch narrowing that may explain the HTN)
Class IIa, level of evidence C
Besides systemic HTN, what are other situations where stent placement for CoA may be indicated even if the transcatheter gradient is <20mmHg?
- Significant collaterals*
- Elevated LVEDP*
- Poor LV function**
- Significant AI**
- (Class IIb, level of evidence C)
- *May be associated with heart failure
True or False: In adolescents, transcatheter stent placement is an acceptable/safe alternative to surgical treatment for CoA?
True- An adult sized stent can be placed, outcomes are comparable to surgical intervention
What testing can be done to diagnose CoA if TTE has inadequate views?
- MRI- Phase contrast MRI can quantify amount of collateral flow in presence of CoA
- CT
Stent angioplasty of native CoA is indicated when there is a catheter-measured pressure gradient > _ if an adult-sized stent can be placed
20mmHg
What are some indications for stent angioplasty in patients with CoA who have gradients <20mmHg, depending on arch anatomy?
- Systemic HTN
- Significant collateral flow
- Elevated LVEDP
- Signs of heart failure
A mutation in what gene is consistent with a diagnosis of LQTS type 2?
KCNH2- Encodes K-channel protein
What is “pseudo 2:1 AV block”?
- 2:1 AV block seen in the setting of LQTS
- No disease of AV node causing block
- AV block is functional and due to markedly prolonged repolarization
- Distal conduction system doesn’t fully recover to allow conduction of alternate P waves
True or False: In most patients with LQTS, AV conduction abnormalities (“psuedo 2:1 AV block) normalizes with 1:1 AV conduction if what 2 things happen?
- QTc interval shortens
- HR decreases
What is congenital LQTS?
- Familial condition
- Causes syncope and SCD via polymorphic VT (Torsades de Pointes)… can deteriorate to ventricular fibrillation
- Otherwise healthy
What is the prevalence of LQTS?
1 in 2500
LQTS can be caused my mutation in genes encoding what?
- K channel proteins
- Na channel proteins
- Ca channel related factors
- Membrane adaptor proteins
*At least 13 known genetic forms
Patients with LQTS types 1-3 make up what % of patients with genetically confirmed LQTS?
92%
LQTS type 1?
KCNQ1
LQTS type 2?
KCNH2
LQTS type 3?
SCN5A
What are some ways LQTS can present in fetal life?
- Isolated asymptomatic fetal bradycardia
- Fetal bradycardia
- 2:1 AV block
- Fetal ventricular tachycardia/torsades de pointes
What can be given transplacental in utero for LQTS with fetal ventricular tachycardia/torsades de pointes?
- Mg
- Lidocaine
*Consider delivery if enar term
Which LQTS patients have a very poor prognosis?
- Those with 2:1 AV block in utero/neonatal period
- Mortality >50% first 6 months after birth, up to 67% by age 2 years
What should be done for a neonate with LQTS and 2:1 AV block?
- ICD
- B-blockers
- Na channel blockers
LQTS patients with repeated episodes of trosades de points should have consideration of what?
- ICD
- Left cardiac sympathetic denervation (sympathectomy)
*Possibly both
A congenitally malformed conduction system associated with complex structural cardiac defects is seen in 50-55% of fetuses with what?
Complete heart block
Patients with what type of CHD are at risk of spontaneous complete heart block due to the long course of the AV bundle and fibrosis in the bundle of His?
L-TGA
*AV block can occur in utero or during infancy, with risk increasing linearly with age at a rate of 2%/year
Which type of heterotaxy patients are at risk of rhythm issues?
Poly-splenia… LA isomerism with interrupted IVC (no right-sided heart structures)
What type of rhythm problems can commonly be seen in polysplenia patients?
- Sinus bradycardia: Hypoplasia or absence of sinus node
- Complete AV block: Discontinuity between AV node and His-Purkinje system
True or False: The QTc would be expected to be normal in L-TGA and heterotaxy/polysplenia?
True
What is responsible for nearly 40% of complete heart block in the newborn period?
Isoimmune complete heart block with maternal Sjogran antibodies (SSA/SSB)
*Transplacental transmission of maternal antibodies results in damage to the AV node
Immune mediated complete heart block may benefit from in-utero treatment with what?
- Fluorinated steroids
- IVIG
- Both
True or False: The QTc isn’t significantly prolonged in immune-mediated complete heart block?
True
A combination of bradycardia, 2:1 AV block and polymorphic VT/Torsades in the fetus should make the clinician suspicious for what?
Congenital LQTS
What should be considered as a possibility for the cause of 2:1 AV block in a fetus or neonate?
LQTS
Which children are at highest risk for post-operative pulmonary HTN?
- Longstanding unrestrictive L-R shunts (AV canal, large VSD, DORV with unrestricted PBF, Truncus)
- Obstructed pulmonary venous return
Besides type of CHD, what are some other risk factors for post-operative pulmonary hypertension?
- Prematurity
- Pre-existing pulmonary HTN
- Pulmonary hypoplasia (congenital diaphragmatic hernia)
- Genetic conditions (T21)
What does an elevated (>5mmHg difference) gradient between the PaCo2 and ETCO2 indicate?
-Significant dead space: Inspired air doesn’t reach the well-perfused alveoli (remains in conducting airways or alveoli aren’t adequately perfused due to low CO or low PBF)
What are possible causes of a sudden decrease in ETCO2?
- Hyperventilation
- Mechanical problem or equipment failure (obstruction, displacement, loss of ET tube, pneumothorax)
- Pulmonary HTN or reduced pulmonary blood flow
- Cardiac arrest
How does a pulmonary hypertensive crisis present if there is no R-L shunt?
-Reduced CO: Poor perfusion, low ETCO2, shock
What can be done to quickly reduce PVR?
- Maintenance of adequate ventilation
- Sedation/neuromuscular blockade
- Avoid hypoxemia
- Avoid acidosis
- Avoid hypercarbia
- Initiation/increase quick-acting inhaled pulmonary vasodilators (O2, iNO)
- Increase SVR (shift IVS right and maintain RV coronary perfusion- vasopressin)
Why might it be impossible to get ROSC in a patient who had cardiac arrest due to an acute pulmonary hypertensive crisis without ECMO?
-Vicious cycle: Reduced pulmonary perfusion - Hypoxemia/Hypercarbia/Acidosis - Worsened PVR
iNO doses exceeding what haven’t been shown to be beneficial in further reducing PVR?
20ppm
What is a critical indicator of pulmonary blood flow and CO in the post-op period?
EtCO2
How should an acute pulmonary hypertensive crises be managed?
- Decrease PVR: Increase FiO2, increase ventilation, mitigate acidosis, pulmonary vasodilators (iNO), sedation, paralytic
- Increase SVR: Shift IVS rightward/maintain RV coronary perfusion (Vasopressin)
What is the most common congenital heart defect?
Bicuspid aortic valve
*1-2% of population
Describe a bicuspid aortic vavle
- Partial or complete fusion of 2 of the AoV leaflets, with or without central raphe
- Results in partial or complete absence of a functional commissure between the fused leaflets
- Combined leaflet is larger than the unaffected elaflet
List the types of commissural fusion in bicuspid aortic valves from most common to least
- Right-left (70%)
- Right-non (28%)
- Left-non (rare)
*True bicuspid valve with on 2 leaflets is very rare
True or False: Most children’s diagnosed with bicuspid aortic valve are asymptomatic?
True
PE findings of a bicuspid aortic valve in children are often very subtle in absence of significant valve dysfunction?
True
In what % of patients is bicuspid aortic valve an isolated finding?
50-60%
True or False: In bicuspid aortic valves, if there is valve dysfunction, it is often mild?
True (AS or AI)
Ascending aorta dilation occurs in what proportion of patients with a bicuspid aortic valve?
Half
*Often clinically silent into adolescence, but bicuspid aortopathy can lead to aneurysm formation/aortic dissection in adulthood
Congenital bicuspid aortic valve is often seen with what other type of CHD?
Left sided obstructive lesions
What proportion of patients with CoA have a bicuspid aortic valve?
Half- Most with fusion of the intercoronary commissure
What family screening should be done for bicuspid aortic valve?
-Screen 1st degree relatives with echo
True or False: Isolated bicuspid aortic valve with mild or no stenosis and/or regurgitation at initial evaluation has a favorable natural history?
True- Often little to no disease progression during childhood
*Regardless, patients need to be followed throughout their life for disease progression
Patients with bicuspid aortic valve and what type of fusion are at greater risk for valve dysfunction?
Right-non
Patients with severe stenosis due to bicuspid aortic valve tend to present when?
At a young age
*Balloon valvuloplasty may postpone surgery, but repair or replacement may be needed during childhood
Bicuspid aortic valve is associated with what?
- AS
- AI
- CoA
- Aortopathy
What is the most common valve morphology in bicuspid aortic vavle?
Fusion of right and left coronary cusps
What is the most influential donor organ cariable associated with post-transplant outcomes in heart transplant?
Donor EF
*Systolic dysfunction associated with worse graft outcome
True or False: The presence of LV dysfunction on a single echo isn’t a contraindication for donor heart acceptace?
True- Many centers would ask for repeat echo off inotropes to reassess systolic function
- Systolic dysfunction has been associated with worse graft outcome
- Systolic dysfunction can be associated with head trauma, brain death, or organ management strategy
- Systolic dysfunction may be transient or subject to variable interpretation
True or False: When systolic function of a potential donor heart is normal, most other donor factors become less relevant?
True
Which factor is the most influential donor variable associated with posttransplant outcomes for heart transplant?
Systolic function
What type of SVT is due to an accessory pathway with slow and decremental conduction properties?
PJRT
Describe a PJRT circuit
- Antegrade conduction over AV node (narrow QRS complex)
- Slow retrograde conduction over AP
- AP commonly in right posteroseptal region, atrial depolarization spreads inferior to superior (negative P waves in II, III and aVF)
- As retrograde conduction over AP is slow, takes longer for retrograde conduction and thus long RP inerval
Why are heart rates in PJRT slower than most other types of SVT?
Slow retrograde conduction over AP causes a long RP interval
*SVT rate can be as slow as 140-150bpm
What makes PJRT such an incessant tachycardia?
- Slower retrograde conduction over the AP allows the AV node to recover and be ready to conduct antegrade
- Normal slowing in the AV node then allows the AP to recover in time to conduct retrograde
*This completes the reentrant SVT loop
Tachycardia induced cardiomyopathy was seen in what % of patients with PJRT?
18%
True or False: Tachycardia induced cardiomyopathy is mostly reversible once PJRT is controlled?
True- May need ECMO initially
Which type of SVT is very difficult to control and often requires multiple antiarrhythmic drugs?
PJRT
What is the most commonly used anti-arrhythmic medication in the acute setting for PJRT with myocardial dysfunction?
Amiodarone
*Some might try B-blockers, but less likely to work
Once out of the acute setting following presentation for PJRT +/- assocaited tachycardia induced cardiomyopathy, what are PO antiarrhythmics that may be used?
- Flecainide
- Sotalol
- Digoxin
- B-blocker
True or False: PJRT responds to adenosine or cardioversion
False- Response is transient and tachycardia will resume once the terminating stimulus is removed
When would ablation be considered for PJRT?
- Poorly controlled despite multiple anti-arrhythmics
- Older
*Accessory pathway is close to AV node, so in younger patients ablation needs to be done cautiously to avoid AV block
What is the differential diagnosis of long RP tachycardia?
- Atypical AVNRT
- PJRT
- EAT
- Sinus tachycardia
What is a type of SVT that is difficult to control and can be incessant, resulting in tachycardia-induced cardiomyopathy?
PJRT
*Tachycardia induced cardiomyopathy often reversible with arrhythmia control
Why is PJRT easily confused with sinus tachycardia?
- Slower rate of PJRT
- Visible P waves
- Normal appearing PR interval
What about the P-waves could suggest a PJRT?
Negative P-waves in the inferior leads
What should be considered in a young patient with heart failure symptoms and unexplained tachycardia?
PJRT- Look at P-wave axis
What is the differential diagnosis of a long RP tachycardia?
- Atypical AVNRT
- PJRT
- EAT
- Sinus tachycardia
Pericardial effusion and pleuritic chest pain after cardiac surgery suggests what?
Post-pericardiotomy syndome
What causes post-pericardiotomy syndrome?
Immune-mediated inflammatory process after pericardial injury
When is post-pericardiotomy syndrome often seen?
First few weeks post-op
*11% of pediatric patients develop clinically relevant pericardial effusion within 1 month of surgery, <2% require admission, 1/2 admitted need pericardiocentesis
What are risk factors for effusions requiring readmission after pediatric cardiac surgery?
- Older age at initial surgical admission
- Specific surgical procedures (heart transplant, ASD)
In developed countries, most cases of pericarditis are due to what?
Idiopathic (presumed viral)
*80-90%)
Postpericardiotomy syndrome is a non-infectious cause of pericarditis that accounts for what % of cases with an identified etiology?
2-7%
How is acute pericarditis diagnosed?
Need 2 of following:
- Chest pain (sharp/pleuritic, improved by sitting up or learning forward)
- Pericardial friction rub
- Suggestive change on ECG
- New/worsening effusion
What is 1st line therapy for pericarditis/pericardial effusion?
NSAIDS (Class I)
What medication is a useful adjunct to NSAIDS for pericarditis/pericardial effusion?
Colchicine (Class IIa)
What medication is not recommended in children for pericarditis/pericardial effusion?
ASA (Reye syndrome/hepatotoxicity)
What are the current views on use of steroids in pericarditis/pericardial effusion?
- Used to be initial choice for effusion or no response to NSAIDS
- Not as favored now: Higher adverse-effect profile, higher associated with of recurrent pericarditis
*May still be used in refractory cases or if there is an underlying autoimmune or connective tissue disease (where steroids are part of standard therapy)
When combined with NSAIDS, what drug has been shown to improve remission rates and prevent recurrences?
Colchicine
What is the optimal duration of anti-inflammatory therapy in children for pericarditis/pericardial effusion?
1-2 weeks or until symptoms resolve
What are the thresholds for respiratory variations across the AV valves on echo for tamponade?
> 30% change in peak mitral E wave velocity
>60-70% change in peak tricuspid E wave velocity
What is a subtype of noninfectious pericarditis that usually has delayed onset after pericardial injury?
Postpericardiotomy syndrome
Which patients is postpericardiotomy syndrome more common in?
- Older children
- After certain types of surgeries (ASD)
What is the 1st line therapy for nonbacterial causes of pericarditis?
NSAIDS (ibuprofen)
If NSAIDS don’t improve symptoms associated with pericarditis, what is a useful adjunct?
Colchicine
What medication at high doses is recommended as 1st line therapy for acute pericarditis in children until complete symptom resolution?
NSAIDS (class I)
What should be considered as an adjunct to anti-inflammatory therapy for acute recurrent pericarditis in children?
Colchicine (class IIa)
<5 0.5mg/day
>5 1-1.5mg/day in 2-3 divided doses
What drugs may be considered in children with recurrent pericarditis (especially when steroid dependent)?
Anti-IL-1 drugs (class IIb)
What medications aren’t recommended in children with pericarditis?
- ASA (Reye’s and hepatotoxicity) (class III)
- Steroids (side effects, unless specific indication like autoimmune disease) (class III)
What anatomy can reverse differential cyanosis be seen in?
TGA with PDA and elevated PVR in newborn period
- R-L (PA to Ao) flow across PDA with increased PVR will shunt the pink blood across the PDA to the descending aorta at level of PDA, but ascending aorta is still getting deoxygenated blood
- Finding is transitory and disappears as PVR falls and ductal flow isn’t bidirectional or R-L (goes all from Ao-PA, L-R)
What is Qp?
Entire amount of flow that traverses the pulmonary vascular bed
What is Qep?
- Effective pulmonary blood flow- Flow of systemic venous blood into the pulmonary circulation
- Deoxygenated blood that is being sent to the lungs to undergo oxygenation
In TGA, which is higher, Qep or Qp?
Qp
-In a normal heart, Qp is equal to Qep
What is the goal of keeping the PDA open with PGE in TGA?
- Increase effective pulmonary blood flow
- Blood flowing from the Ao to PA across the PDA is deoxygenated blood being sent to the lungs to pick up O2
*Not mixing of blood within the ductus or back-and-forth flow across the ductus… it is greater net flow across the ductus
Describe the effective blood flow in TGA physiology
- Blood from Ao to PA across the PDA is the deoxygenated blood being sent to the lungs to pick up oxygen (keeping PDA open increases the effective pulmonary blood flow)
- Increased flow across the PDA results in increased pulmonary venous return to the LA
- Relative increase in LA pressure is stimulus for more blood to go across PFO to RA… more LA-RA flow across PFO will increase effective systemic blood flow (Qes) or flow of oxygenated blood being sent to body to deliver O2
True or False: PGE has a short half life?
True
What time is does the maximum response to PGE occur in?
15 minutes to 4 hours after starting the infusion
What is the optimal dosing for PGE?
- Range is 0.01 to 0.1ug/kg/min
- Once PDA open, patency should be maintained at the lowest effective dose
What are some side effects of PGE?
- Hypotension
- Hypoventilation
- Cutaneous flushing
- Fever
- Apnea*
- Systemic hypotension*
- Pulmonary vasodilation*
- More common at higher doses
- Should be able to support ventilation when starting pGE
What does a PDA in TGA allow for?
Deoxygenated blood in the aorta to flow into the PA and lungs (which increases the effective pulmonary blood flow)
What is the differential diagnosis for long RP narrow complex tachycardia?
- Sinus tachycardia
- EAT
- Atypical AVNRT
- PJRT
A p-wave axis that is negative leads I and V6 indicate an atrial focus where?
Left atrial ectopic focus
Patients with incessant tachycardia will ultimately develop what?
Tachycardia-induced cardiomyopathy
*Most patients with tachycardia >48 hours will have symptoms of heart failure at the time of presentation
True or False: With control of SVT, the cardiac function usually recovers in tachycardia-induced cardiomyopathy?
True
What needs to be monitored closely in infants receiving amiodarone?
-Hemodynamics… can develop hypotension and decreased CO with a bolus administration
What might you consider giving prior to amiodarone in an infant?
Ca… to reduce changes of worsening cardiac output
How is adenosine helpful in EAT?
- Can help make the diagnosis… AV node will be blocked, but will see p-waves marching through
- Small % of EAT, adenosine can terminate rhythm
What usually causes EAT?
Abnormal automaticity of atrial myocardium
*Not a reentrant type of circuity
What is the effect of cardioversion in EAT?
Usually has a brief suppression of tachycardia before focus of automaticity takes over again
How does verapamil work for SVT?
Blocks conduction at the AV node
What would be the effect of verapamil for EAT?
Slow ventricular response, but no effect on the ectopic focus
In which patients should CCB be avoided?
Infants… myocardium is susceptible to calcium channel blockade which can lead to hemodynamic compromise and/or collapse
Why should epinephrine be used with caution in patients with tachycardia-induced cardiomyopathy?
Can be arrhythmogenic and could worsen underlying arrhythmia
True or False: At birth, healthy term infants frequently have a pure R wave in V1 with an upright T wave?
True
What changes are seen on ECG within the first week after birth?
T-wave in V1 inverts
The normal inversion of the T1 wave in V1 within one week following birth is a sign of what?
Falling PVR and pulmonary pressures as the pulmonary vascular bed vasodilates in the context of normal breathing
*If this transition fails to occur, may be a sign of pathology like pulmonary HTN
Describe changes in lead V1 on ECG as a child ages
- Relative dominance of S-wave in V1 becomes progressively greater (beyond 8, V1 usually has S wave predominance)
- T-wave remains inverted until sometime between 12-16
Describe a normal V1 in pre-school aged children?
- Equiphasic R and S waves
- Inverted T waves
True or False: An upright T wave in V1 in an infant older than 1 week may be a sign of cardiac pathology
True
What are some of the potential sources of pulmonary blood flow in ToF + PA?
- PDA
- Collaterals directly from aorta or branches
- 5th aortic arch
- Coronary to PA collaterals
- AP fenestration
*Multiple sources of pulmonary arterial supply often seen in same patient
Describe the PAs in ToF + PA with PDA as the only source of pulmonary blood flow?
Central PAs that are usually confluent and adequate in size
*Normal arborization pattern of PAs typically
Bilateral PDAs supplying the branch PAs are more commonly seen in ToF + PA with what?
Asplenia/Heterotaxy
*Usually branch PAs are discontinuous
Describe AP collaterals seen in ToF + PA
- Mosaic distribution
- Commonly arise from thoracic aorta or branches (sometimes abdominal aorta)
- Connect to central PAs, distal branches, or directly enter lungs to supply parenchyma
- Vary widely in number, caliber and area of supply
- Usually tortuous
- Propensity of intrinsic stenosis
Describe the central PAs in ToF + PA
- Usually hypoplastic, possible discontinuous or even absent
- Pulmonary arterial arborization pattern normal
True or False: Infants with ToF + PA + MAPCAs often have minimal cyanosis in the first few weeks of life?
True
*As infant grows, pulmonary blood flow usually becomes inadequate and cyanosis worsens
True or False: It is possible to develop pulmonary overcirculation in the setting of ToF + PA + MAPCAs?
True- especially if there are multiple large collaterals
- Pulmonary overcirculation can occur once PVR drops
- Sometimes need medical or interventional management of pulmonary overcirculation
For ToF + PA + MAPCAs, why might cath, CTA or MRI be required prior to surgery?
- For planning- if PAs aren’t confluent very hypoplastic or supplied by multiple collaterals, echo may be inadequate for details
- Arterial supply of each bronchopulmonary segment (including interconnections to adjacent bronchopulmonary segments) should be defined
- This is needed to help decide specific collaterals that will need to be unifocalized surgically
Clinical presentation of ToF + PA depends on what?
Source and extent of pulmonary blood supply
Pulmonary blood flow in ToF + PA can be derived from what?
PDA, AP collaterals or combination
What is necessary to delineate PA architecture prior to surgery in ToF + PA + MAPCAs?
- Cath
- CTA
- MRI
What should be considered as a potential cause for cyanosis and tachypnea in an infant s/p Norwood-Sano?
Sano thrombosis
What 2 things can be given in the setting of a Sano shunt thrombosis?
- IV heparin
- IV TPA
What should be monitored when giving an infant heparin or TPA?
Any signs of bleeding (especially intracranial hemorrage)
Besdies heparin or TPA, what other measures could be beneficial with a Sano thromboss?
- Fluid bolus
- IV pressures
*Increase forward flow across the Sano shunt
What things should be avoided in the setting of a Sano thrombosis?
- Anything that would decrease systemic BP and decrease forward flow an already obstructed Sano shunt
- Esmolol, Lasix, sildenafil, etc.
True or False: Medical therapy is usually not adequate to sufficiently correct cyanosis caused a Sano shunt thrombosis
True
What is definitive intervention for acute shunt thrombosis/stenosis?
Surgery- Sano shunt revision or early superior cavopulmonary shunt placement
*Can also consider stenting the Sano
What are things that can cause narrowing of a Sano shunt?
- Endothelial overgrowth within the Sano
- Dynamic compression
- Anastomotic narrowing
- Kinking of the shunt
- Thrombotic complications (infection)
What is the thrombosis risk in patients with shunt-dependent single ventricle physiology?
8-12%
What is something that increases baseline risks for thrombosis in a Sano shunt?
Previously placed stents in the Sano shunt
True or False: Embolic complications are rarely reported in shunt-dependent single ventricle physiology?
True
Prophylactic use of what after a Norwood may decrease the risk of shunt thrombosis in infants with CHD?
ASA
Patients who have evidence of acute shunt stenosis should be assessed for evidence of what?
Concomitant infection (high incidence of infection)
- Even without fever or other signs of systemic infection
- Evidence of infection or the presence of a + blood culture could affect the timing and type of intervention for acute Sano shunt thrombosis
List 4 major complications after Norwood-Sano
- Shunt narrowing of shunt thrombosis
- Restriction of the atrial septum resulting in LA HTN, pulmonary edema, decreased CO, cyanosis
- Recurrent CoA resulting in UE to LE BP gradient, decreased ventricular function, pulmonary edema, evidence of decreased CO or a combination of the 3
- Aneurysm or pseudoaneurym of the RVOT/Sano connection which may cause acute respiratory symptoms due to mass effect or infectious symptoms, or could be noted incidentally on a CXR or echo
What should be suspected in patients with acute cyanosis who have HLHS that have undergone Norwood-Sano?
Shunt thrombosis
Stage 1 single ventricle patients with shunt thrombosis have a high risk for what?
Infection
Besdies thrombosis, what are other etiologies for shunt narrowing after Norwood-Sano?
- Endothelial overgrowth within Sano shunt
- Dynamic Compression
- Anastomotic narrowing
- Kinking of the shunt
What is the expected flow across the atrial septum and PDA in an infant with Ebstein anomaly?
- Atrial septum: R-L
- PDA: L-R
What limits the opening of the PV in infants with Ebstein?
- Severe TR
- Elevated PA pressure (from high PVR and PDA flow)
What is the difference between functional and anatomic pulmonary atresia in Ebstein?
- Functional: Limited opening of the PV in the setting of severe TR combined with elevated PA pressure (from high PVR and PDA flow). This type of valve may eventually demonstrate antegrade flow with time.
- Anatomical: Requires intervention if antegrade flow is expected to occur
*Distinguishing between functional v. anatomic PA can be difficult via echo (especially if the valve cusps are thin)
A newborn with severe TR and hypoxia may be treated with PGE to maintain pulmonary flow by maintaining the PDA and shunting blood L-R if what is true about the pulmonary valve?
It is competent… pulmonary insufficiency in this setting could lead to a circular shunt
Describe a circular shunt (severe TR, atrial level communication, sizable PDA, significant PI)
- Blood from Ao across PDA to MPA
- Due to PI, goes back to RV
- Due to TR, goes back to RA
- Goes from RA to LA across ASD
- LA to LV
- LV to Ao
- Starts again
What are the hemodynamic consequences of a circular shunt?
- Poor pulmonary perfusion: Ductal flow goes to RV versus distal branch PAs
- Poor systemic perfusion: Blood is shunted away from high pressure systemic circulation into lower-pressure right side of heart
*Results in severe hypoxia and acidosis, often lethal
True or False: Pulmonary insufficiency is often well-tolerated for a long period of time, even in neonates?
True- Half of patients were symptomatic before age 50
*In the neonates, as long as branch PAs weren’t big enough to cause compression of airways, infants did well
What are symptoms of isolated PI?
- Often seen in adults
- Tachycardia or palpitations
- Effort intolerance
- Dyspnea
- New-onset peripheral edema
True or False: Congenital PI and absent pulmonary valve have very different hemodynamic effects?
True-
- Congenital PI often well tolerated and can be managed conservatively
- Absent PV has high risk of airway compromise from severely dilated pulmonary arteries
Absent pulmonary valve typically occurs in the setting of what?
VSD- ToF absent PV
*Can see cases with IVS though
What causes most cases of chronic PI?
*Result of intervention on the PV to relieve obstruction
- Balloon dilation of PS
- Surgical relief of pulmonary outflow obstruction (often during repair of ToF with transannular patch)
- Surgical repair with RV-PA conduit placement with eventual valve deterioration and resultant regurgitation
What are the effects of chronic pulmonary insufficiency?
- RV enlargement
- RV dysfunction
*Effects usually take several years to become apparent
True or False: PI typically is tolerated very well in isolation?
True
In what circumstance can PI be lethal?
Circular shunt
*Atrial communication, TR, PDA, PI
What is the abnormal arrangement of abdominal organs and cyanotic heart disease often seen in?
Heterotaxy
Asplenia with an intact IVC suggests what?
Right isomerism
What is isomerism?
Morphologic mirror-imagery (or symmetry) in the same patient
- Abnormal visceral arrangement with asplenia
- Bilateral morphologic right atrial appendages
- Bilateral eparterial bronchial branch patterns
- Intact IVC
Right isomerism
Which side has a short main bronchus with a branch to the upper lobe that passes above the PA (eparterial bronchus, the bronchus above the PA)?
Right
Which side has a long main bronchus and the PA courses backward over the upper lobar bronchus (hyparterial bronchu, bronchus below the PA)?
Left
Eparterial bronchi?
Right
Hyparterial bronchi?
Left
What is an eparterial bronchus?
Bronchus goes above the PA (right)
What is a hyparterial bronchus?
Bronchus goes below the PA (left)
What is the rule with heterotaxy?
- Findings are unpredictable… there are associations of classic right and left isomerism, but no rules
- Need individualized, segment-by-segment analysis
*One study showed 20% of patients with heterotaxy have discordant bronchopulmonary branching, atrial appendage arrangement and splenic status
Describe the normal tracheobronchial tree
- Short, eparterial right-sided bronchus
- Long, hyparterial left-sided bronchus
What should a symmetrical or mirror-image pattern of the tracheobronchial tree raise concern for?
Isomerism
Right bronchial isomerism is commonly seen then there is also what?
Right isomerism of the atrial appendages
*Morphology of the tracheobronchial tree often correlates well with the anatomy of the atrial appendages
What are the 3 segments often analyzed in heterotaxy?
- Atrial appendage arrangement
- Bronchopulmonary branching
- Splenic status
*Anatomy can be variable and discordance between organ systems isn’t uncommon
Tuberous sclerosis complex is most commonly caused by a mutation in what gene?
TSC
What is pathognomonic for tuberous sclerosis complex on fetal echo?
Presence of multiple cardiac tumors
What is the most common fetal presentation of tuberous sclerosis complex?
Presence of multiple cardiac tumors
How is tuberous sclerosis inherited?
AD
What is characterized by abnormal cellular hyperplasia and dysplasia resulting in neurocutaneous and cardiac abnormalities?
Tuberous sclerosis complex
75-90% of tuberous sclerosis cases are caused by mutations in what genes?
- TSC1 (9p34)
- TSC2 (16p13)
Mutations in TSC1 causing tuberous sclerosis cause dysfunction of what?
Hamartin (10% of cases of TS)
Mutations in TSC2 causing tuberous sclerosis cause dysfunction of what?
Tuberin (90% of cases of TS)
Does TSC1 or TSC2 present with a more severe clinical phenotype?
TSC2- But there is significant heterogeneity between individuals with TSC1 or TSC2
How is tuberous sclerosis complex inherited?
AD, but up to 65-75% of cases are caused by spontaneous mutations
What needs to be included in genetic counseling of a family with a baby who has Tuberous Sclerosis?
Prenatal testing… want to determine is TSC mutation is spontaneous or familial
Tuberous sclerosis complex inhibits cell growth through what?
Rapamycin complex (mTOR)
Mutations of TSC1 and TSC2 (Tuberous sclerosis) lead to various types of growth proliferation including what?
- Cardiac rhabdomyomas
- Brain subependymal nodules
- Cortical tubers
- Renal cysts
What medications are used to treat certain manifestation of Tuberous sclerosis complex (including large, symptomatic neonatal cardiac rhabdomyomas)?
- Everolimus and sirolimus
- mTOR inhibitors
What are the important factors determining outcomes in a fetus with evidence of tuberous sclerosis?
- Size/location of cardiac tumors (rhabdomyomas)
- Presence and type of any cardiac rhythm abnormality
Cardiac rhabdomyomas in tuberous sclerosis occur most commonly where?
Within the ventricles or in the ventricular septum
*Can be varying in size and potentially obstruct blood flow
If there is any concern for obstruction due to a rhabdomyoma in fetal life, what should be recommended?
Delivery at a center where cardiac care/intervention is possible
True or False: Cardiac rhabdomyomas typically increase in size during the second half of gestation?
True
True or False: Cardiac rhabdomyomas involute postnatally?
True (80-90%)
By age 2, what % of children with tuberous sclerosis have rhabdomyomas visible by echo?
20%
What are some of the rhythm abnormalities seen in tuberous sclerosis?
Non-sustained or sustained atrial and/or ventricular arrhythmias
*Vary widely and can occur at any age
What do patients with tuberous sclerosis need long-term cardiac surveillance for?
Arrhythmia- may develop at any age and even in absence of significant cardiac rhabdoymyomas
Supra-aortic valve narrowing can be seen prenatally in infants with what mutation?
ELN (Williams syndrome)
Increased nuchal translucency, cystic hygroma and polyhydramnios can be seen in fetuses with what mutation?
PTPN11 (Noonan)
True or False: Cardiac anomalies commonly found in Noonan (ventricular hypertrophy, supra-valvar PS) may not be seen prenatally?
True- may only see other suggestion of Noonan like increased nuchal translucency, cystic hygroma and polyhydramnios
Arrhythmias with HCM can be seen prenatally in fetuses with what mutation?
HRAS (Costello syndrome)
Most cases of tuberous sclerosis complex are caused by mutations in what?
TSC2
Multiple cardiac rhabdomyomas?
Tuberous sclerosis
When are the cardiac rhabdomyomas largest during fetal life in patients with tuberous sclerosis?
Second half of gestation
What 2 things are postnatal cardiac manifestation of tuberous sclerosis complex based on?
- Size/location of cardiac rhabdomyomas
- Presence of cardiac arrhythmias
Even when cardiac rhabdomyomas have resolved, patients with tuberous sclerosis need continued monitoring for what?
Arrhythmia
What is hydrops fetalis?
Abnormal fluid collection in fetal soft tissues and/or serous cavities… must have 2+ of ascites, pleural effusion, pericardial effusion or skin edema
How does a fetal pleural effusion appear?
Rim of echolucent fluid just inside the chest wall outlining the lungs
How does fetal ascites appear?
Echolucent fluid inside the abdominal wall, outlining the liver and compressing the bowel
Cardiovascular abnormalities are responsible for what % of cases of hydrops fetalis?
17-35%
In fetal SVT, what % of cases are associated with hydrops?
40-50%
Why does fetal SVT cause hydrops?
- Impaired diastolic filling and poor ventricular function increase CVP
- Higher CVP transmitted back through venous system increasing transudative forces causing cell/tissue edema
What is the mainstay of treatment for fetal SVT?
Maternal transplacental treatment initiated in the hospital with monitoring of Mom’s ECG
*Really no established guidelines or uniform standards… treatment based on expert opinion with institutional variability
If there is no hydrops, what is often the first choice medication used for fetal SVT?
Digoxin
*Safe, been used for a long time, ~50% response rate
What is the approximate response rate for fetal SVT with digoxin (no hydrops)?
50%
What is the approximate response rate for fetal SVT with digoxin if hydrops has developed?
25%- Transplacental passage of medication to fetus is significantly reduced
What medication for fetal SVT has good placental transfer even with hydrops?
Sotalol
In the setting of fetal SVT with hydrops, what is a reasonable medication regimen?
Digoxin + Sotalol
- Can also consider flecainide
- Requires frequent re-evaluation of treatment response
Maintenance digoxin dosing for fetal SVT is guided by what?
- Maternal serum levels (goal range 1-2ng/mL*)
- Maternal ECG findings
- Maternal symptoms of toxicity
*Can consider higher than 2ng/mL if ECG okay and no toxicity symptoms
What is an option for a fetus with uncontrolled SVT that is close to term?
Delivery and newborn therapy
The diagnosis of hydrops is based on the presence of what?
2+ of skin edema, pleural effusion, pericardial effusion or ascites
What factors likely contribute to the increased risk of stroke seen both early and late after a Fontan surgery?
- High venous pressures
- Liver disease
- Abnormal inflammation and coagulation profiles
- Ventricular dysfunction
- R-L shunts
- Low flow state
- Arrhythmias
What is the leading cause of strokes in children?
CHD
Most strokes related to CHD are what type?
Ischemic or ebmolic
Hemorrhagic strokes in children are often seen in what setting?
ECMO
VAD
What should be considered for a patient who underwent enlargement of a Fontan fenestration with new altered mental status and focal neurological deficit?
Stroke
True or False: In most cases of acute ischemic stroke related to CHD, the results for intracardiac thrombi (with TEE) are often negative?
True
Why are coagulation studies often abnormal in Fontan patients (even those not taking warfarin)?
FALD
*Failing Fontan patients with abnormal liver function are at high risk for stroke
True or False: A head CT is the preferred test to detect an acute ischemic or embolic stroke?
False- Head CT is good for intracranial hemorrhage or cerebral edema, but results are often no abnormal in patients with an acute ischemic/embolic stroke
If a patient who is on ECMO, has a VAD or is fully anticoagulated has stroke-like symptoms, what is the test of choice for diagnosis?
Head CT- more likely to be a hemorrhagic stroke in this setting (v. ischemic/embolic where CT may not be helpful)
What is the diagnostic test of choice for an acute embolic stroke?
MRI
True or False: If an MRI cannot be readily obtained with suspicion for an acute embolic/ischemic stroke, a head CT should still be done
True- especially if considering thrombolytic therapy to rule out any intracranial hemorrage
In pediatrics, what is one of the leading causes of stroke?
Cardiac diseases
What sub-group of pediatric cardiology patients are at high risk for stroke?
Fontan
What should be done if there are new neurological symptoms in a single-ventricle patient?
MRI (preferably)
True or False: Head CT may have normal findings immediately following an acute thromboembolic or ischemic stroke
True
Heart failure stage B?
- Cardiac morphology and function are abnormal
- No past or current heart failure symptoms
What 2 medications should be started in pediatric heart failure stage B?
- ACEi
- B-blocker
What is the role of ACEi or B-blocker in heart failure stage B?
Promote reverse remodeling and delay disease progression
For a patient with stage B heart failure and NSVT on Holter, what medication should be started?
B-blocker like carvedilol
- Has reverse remodeling potential
- Could suppress ventricular arrhythmias
Besides carvedilol, what other beta-blocker has reverse remodeling effects?
Metoprolol succinate (long-acting)
*Doesn’t com in liquid formulation
Which form of metoprolol (succinate or tartrate) has reverse remodeling effects in heart failure?
Succinate
- Succinate: Long acting, no liquid, yes reverse remodeling
- Tartrate: Short acting, yes liquid, no reverse remodeling
In pediatric heart failure, anti-arrhythmic medications can be considered in individual cases if…
- Electrolyte levels normal
- Other metabolic derangements corrected
- Arrhythmia poorly tolerated
*Routine use of antiarrhythmics isn’t recommended
True or False: In adults, NSVT in non-ischemic cardiomyopathy is not used as a criteria for ICD?
True- NSVT very common
-Frequency of ventricular ectopy does correlate to sudden death risk, but hasn’t been shown to predict sudden death independent of other known clinical factors
Which group has a higher incidence of NSVT, pediatric patients or adult patients with DCM?
- Adults (50-80%)
- Children is 10-20%
True or False: The risk for SCD with NSVT in patients with DCM is poorly understood in pediatrics?
True
*SCD is rare overall in DCM in pediatrics (3% at 5 years and 5% at 15 years)
When is amiodarone used in patients with DCM?
Treatment of NSVT that is very frequent or symptomatic despite treatment with B-blockers
*Risk of long-term adverse effects and lack of survival benefit
When is an EP study indicated in cardiomyopathy?
If there is very frequent, monomorphic ventricular ectopy that is thought to be the cause of the cardiomyopathy
*No role with DCM and ventricular ectopy
Patients with NSVT in DCM should be treated with what medication as part of their heart failure regimen?
-B-blocker (carvedilol or long acting metoprolol- succinate)
True or False: There is no role for use of antiarrhythmics (besides B-blockers) for asymptomatic NSVT in pediatric DCM to reduce risk of SCD?
True
6-days of fever, cervical lymphadenopathy, respiratory distress, tachycardia, hypotension, decreased perfusion, echo with depressed LV systolic function, mild MR, dilated LAD
Kawasaki with KD shock syndrome
Kawasaki disease is usually seen in what age group?
<4
*Acute, self-limited idiopathic febrile illness
What is the most common cause of acquired heart disease in children in developed countries?
Kawasaki
Kawasaki disease leads to coronary aneurysms in what % of untreated patients?
25
Kawasaki disease leads to coronary aneurysms in what % of children treated with IVIG in appropriate time?
4%
What is an acute febrile illness that can result in vasculitis of medium-sized arteries (especially the coronary arteries)?
Kawasaki
How is Kawasaki disease diagnosed?
- Fever for more than 4 days
- At least 4/5 following:
- Bilateral, nonexudative, limbic-sparing conjunctivitis
- Oropharyngeal changes- erythema/cracking of lips, strawberry tongue, erythema of oral and pharyngeal mucosa or combination
- Maculopapular, diffuse erythroderma or erythema multiforme-like rash
- Erythema and edema of the hands and feet in acute phase, periungual desquamation or both
- Cervical lymphadenopathy >1.5cm, usually unilateral
Describe the fever seen in KawasakI?
- Abrupt onset
- Higher than 39C
Without treatment for Kawasaki, how long can the fever last?
11-12 days
True or False: The presence of coronary artery dilation with high fever for more than 4 days is sufficient to diagnose atypical Kawasaki?
True
What are echo features considered diagnostic of acute Kawasaki?
- Z-score of LAD or RCA >2.5
- Coronary artery aneurysm observed
- 3+ of decreased LV function, MR, pericardial effusion or Z-score in LAD or RCA 2-2.5
True or False: Microscopic evidence of myocarditis can be found in virtually all patients with acute Kawasaki?
True
True or False: LV systolic dysfunction is common in KawasakI?
False- Less common (only seen in 20% of patients diagnosed with acute Kawasaki)
*Symptomatic cardiac failure is uncommon in acute Kawasaki
How does valve regurgitation present in patients with acute Kawasaki disease?
Usually mild MR (25% of patients with Kawasaki)
What is Kawasaki shock syndrome?
Patients with Kawasaki who have hemodynamic compromise
What causes the hemodynamic compromise in Kawasaki shock syndrome?
- Systolic ventricular dysfunction consistent with myocarditis
- Vasoplegia consistent with systemic capillary leak syndrome
What lab abnormalities are often seen with Kawasaki shock?
- Marked elevation in inflammatory markers
- Coagulopathy
- Anemia
- Thrombocytopenia
True or False: There are always coronary artery abnormalities with Kawasaki shock syndrome?
False- more common with KD shock, but can happen in absence of acute coronary artery abnormalities
*Myocardial inflammation may occur before coronary artery abnormalities arise
What is the treatment for Kawasaki?
IVIG
What can be given in addition to IVIG for Kawasaki shock syndrome?
- 2nd dose IVIG
- Infliximab
- Anakinra
- Methylprednisolone
True or False: Patients with Kawasaki shock syndrome can be relatively resistant to IVIG?
True
True or False: Patients with Kawasaki shock syndrome are at increased risk of developing coronary artery aneuryms
True
What Kawasaki patients are at higher risk of developing coronary artery aneurysms?
- Young (<6 months)
- Male
- Asian, Pacific or Hispanic origin
- Fever >8 days
- Recurrence of fever after being afebrile for >48 hours
- Initial Kawasaki shock
When is peak mortality in Kawasaki disease?
15-45 days after fever occurrence
Mortality in Kawasaki disease is often due to what?
Coronary artery vasculitis in the presence of a hypercoaguable state
*Seen in the 15-45 days after fever occurence
Late mortality in Kawasaki disease is often due to what?
- Coronary artery thrombosis (leads to myocardial ischemia/infarction)
- Acute MI in children may be related to missed KD
Hemodynamic compromise, fever, and echo findings consistent with Kawasaki disease?
Kawasaki disease with Kawasaki shock syndomre
Supravalvar aortic stenosis in 2 first degree relatives with no other dysmorphic features or syndromic associations is consistent with that?
Familial supravalvar AS
Familial supravalvar aortic stenosis is associated with a mutation in what gene?
Elastin
What type of genetic testing would be helpful in a child with supravalvar aortic stenosis whose mother also has supravalvar aortic stenosis?
Elastin-targeted gene sequencing
What is a critical structural protein involved in the development and maintenance of arterial walls?
Elastin
People with mutations in elastin are at risk of developing what heart problem?
Supravalvar aortic stenosis
*May also be at a higher risk of other stenoses in the aorta, pulmonary arteries, coronary arteries or renal arteries
How are elastin gene mutations inherited?
AD
Can also be de novo mutations too
Microdeletion of 7q11.23?
Williams
Cardiac problems in Williams?
- Supravalvar aortic stenosis
- Peripheral pulmonary stenosis
- Coronary ostial stenosis
What gene is localized to the microdeletion region associated with Williams syndrome (7q11.23)?
Elastin
Familial supravalvar aortic stenosis is associated with mutations in what gene?
Elastin
What results in deletion and haploinsufficiency of elastin?
Williams syndrome
Williams syndrome has overlap in the cardiac phenotype with what?
Supravalvar aortic stenosis
What genetic testing can be done if there is suspicion for Williams?
- FISH
- Chromosomal microarray
“Elfin facies”, flat nasal bridge, shortened and turned nose, long philtrum, small chin, mild cognitive delay, endocrinopathies (hypercalcemia), ear issues (recurrent otitis media, hearing loss), GI issues (colic, poor weight gain)?
Williams
What test is helpful for infants with significant cardiac disease who also have extracardiac abnormalities?
Chromosomal microarray
What type of genetic testing is useful to look for copy number variants, allowing for surveillance for microdeletions or duplications?
Chromosomal microarray
What test can detect >70% of copy number variants present in people with CHG?
Chromosomal microarray
What 2 tests can detect gene duplications or deletions?
Chromosomal microarray
FISH
What is the difference between chromosomal microarray and FISH?
Both can detect gene duplications or deletion, but FISH only if you know the specific region to target the probe
True or False: FISH isn’t considered a 1st trier test for chromosomal anomalies?
True
What is the 1st tier test to assess for chromosomal microdeletions and duplications?
FISH
What test is useful when there is a high index of suspicion for a genetic disease, but the gene or genes to target are less clear, or when CMA or targeted gene sequencing don’t reveal a diagnosis?
Whole-exome sequencing
Familial supravalvar AS is association with mutations in what gene?
Elastin
How is familial supravalvar AS inherited?
AD or can arise de novo
Microdeletion in 7q11.23?
Williams
Williams causes what problem with elastin?
Haploinsufficiency
Besides cardiac involvement, what other problems are seen in Williams?
- Facial dysmorphisms
- Endocrine problems
- Developmental problems
- GI problems
- Ear problems
Maternal warfarin doses above what are associated with a greater risk of teratogenicity in a fetus?
5mg
During what stage of pregnancy does Warfarin exposure pose the greatest risk to a fetus?
First trimester is greatest risk with minimal risk in 2nd/3rd trimesters
What type of anticoagulation has the lowest risk of adverse maternal outcomes in pregnancy?
Vitamin K antagonists like warfarin
Which type of mechanical valve has a higher risk of thrombosis, aortic or mitral?
Mitral
What is the recommendation for anticoagulation for a mother with a mechanical heart valve in the first trimester of pregnancy?
-Continue warfarin is the dose to maintain a therapeutic INR is less than or equal to 5mg (IIa) over LMWH (IIb) or UFH (IIb)
True or False: It is reasonable to add ASA to warfarin in the 2nd or 3rd trimester for a pregnant woman with a mechanical heart valve?
True
True or False: If a pregnant women with a mechanical heart valve had to transition to LWMH or UFH during the first trimester (because warfarin dose to maintain INR was >5mg), she should continue LMWH or UFH the remainder of pregnancy?
False- should transition back to warfarin for the 2nd/3rd trimesters until just prior to delivery
What type of anticoagulation has the lowest risk of adverse maternal outcomes in pregnancy?
Vitamin K antagonists
Warfarin doses < what are associated with a low risk of fetal teratogenicity, even in the first trimester?
5mg
Warfarin should be continued in the first trimester of pregnancy as the preferred strategy when the dose needed to maintain therapeutic INR is under what?
5mg
What type of AV valves open over the interventricular septum?
Overriding
Overriding atrioventricular valves are always associated with what?
Malalignment VSD (atrial and muscular ventricular septa aren’t in the same plane)
What is the manner in which the atrial connect to the ventricles?
Atrioventricular connection
What are the concordant atrioventricular connections?
RA to RV
LA to LV
What is the manner in which the ventricles connect to the great arteries?
Ventriculoarterial connection
What are the concordant ventriculoarterial connections?
RV to PA
LV to Ao
What is the definition of an overriding AV valve?
Empties into both ventricles
An atrium is considered to join the ventricle into which more than _% of the valve orifice empties?
50%
What is a double-inlet connection?
When both the LA and RA drain in larger part to the same ventricle
What is a univentricular atrioventricular connection?
2 atria to 1 ventricle
What is the usual spatial relationship of the aortic and pulmonary valves in transposition?
Aorta is anterior and right relative to the pulmonary valve
What is a discordant ventriculoarterial connection?
LV to PA
RV to Ao
Which type of segmental anatomy classification scheme is based on connections between the heart structures?
Anderson
Which type of segmental anatomy classification scheme is based on situs and uses alignment (v. connection) to describe the way chambers are joined?
Van Praagh
What is sequential segmental analysis?
- Means of describing all congenital cardiac malformations
- Depends on recognition of anatomy as observed
- Emphasis on morphology of cardiac components and way they are joined
What determines the type of atrioventricular connection present?
Degree of commitment of an overriding atrioventricular valve
What is a double-inlet AV connection?
When most of an overriding valve is connected to a ventricle that is also joined to the other atrium
A wide QRS tachycardia that narrows at the end of the strip with no change in tachycardia cycle length is consistent with what?
SVT that starts with aberrant conduction
*Tachycardia starts wide secondary to the Ashman phenomenon
Describe the Ashman phenomenon
- Refractory period of the bundles depends on teh preceding R-R interval
- At start of a tachycardia (A-fib RVR or aberrantly conducted SVT), the preceding R-R interval is longer than the R-R interval in tachycardia
- Long-short interval affects the refractoriness of bundles and can lead to aberrant conduction
- This is usually RBBB given right bundles longer refractory period
- As tachycardia continues, refractoriness of bundles adjusts to tachycardia rate and is able to conduct which narrows the QRS
*This is what can cause SVT with aberrancy that then becomes narrow
What is a clue to distinguish between atrial fibrillation v. SVT with aberrant conduction in a wide complex tachycardia?
A-fib would have a more irregular rate
A wide complex tachycardia that then narrows, but continues at the same rate tells you it is due to what?
SVT with aberrancy (versus a ventricular tachycardia)
What is seen in SVT when a long-short R-R interval is seen?
Ashman phenomenon
The Ashman phenomenon (SVT when a long-short R-R interval is seen), leads to what?
Aberrancy
Aberrancy during SVT usually has what morphology?
RBBB
Kearns-Sayre syndrome is a type of what?
Mitochondrial myopathy
- Chronic progressive ophthalmoplegia (worsening ptosis and eventual loss of control of eye movements)
- Pigmentary retinopathy
- Cardiac conduction abnormalities
- Neurologic abnormalities (cerebellar ataxia, myopathy, sensorineural hearing loss)
- Endocrine disorders (diabetes, growth hormone deficiency, hypoparathyroidism)
Kearns-Sayre Syndrome
Describe the conduction deficits seen in Kearns-Sayre
- Variable and progressive AV conduction deficits
- May present years after other symptoms
Patients with Kearns-Sayre syndrome are at risk for what?
- Syncope
- Sudden death from AV block
*Require close monitoring of their conduction system
True or False: Consideration of placement of a cardiac pacemaker at the initial signs of AV conduction deficits is needed in Kearns-Sayre?
True
Sudden death in patients with Kearns-Sayre has usually been attributed to waht?
AV block
*But ventricular arrhythmias like TdP with long QTc may play a role
What type of cardiomyopathies is WPW seen in?
HCM
-LVNC
WPW/preexcitation can be seen in association with what type of mitochondrial disorder?
Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS)
Patients with MELAS (mitochondrial encephalomyoapthy with lactic acidosis and stroke-like episodes) can have what 2 cardiac manifestations?
- WPW
- Cardiomyopathies
What is often the presenting arrhythmia in myotonic dystrophy?
Atrial flutter
*Also at risk for developing AV conduction abnormalities
What are 3 circumstances that you might see a bidirectional ventricular tachycardia?
- CPVT
- LQTS type 7 (Andersen-Tawil Syndrome)
- Digoxin toxicity
What rhythm problem do patients with Kearns-Sayre syndrome have?
Progressive atrioventricular conduction abnormalities
Pacemaker placement should be considered in patients with Kearyn-Sayre syndrome who develop what?
Atrioventricular node conduction abnormalties
Myotonic dystrophy patients are at risk for what two rhythm problems?
Atrioventricular conduction abnormalities
Atrial flutter
What rhythm isn’t uncommon in newborns and may be initiated by placement of a CVL?
Atrial flutter
What are the 3 ways atrial flutter can be cardioverted in infants?
- Electrically
- Medically
- Overdrive atrial pacing
How is electrical cardioversion of atrial flutter done?
Synchronized cardioversion (0.5-1J/kg)
What are some of the medications which may be trialed to achieve medical cardioversion?
- Digoxin
- Flecainide
- Sotalol
- Amiodarone
How is overdrive pacing to cardiovert flutter done?
- Transesophageal pacing catheter (esophagus sits directly behind LA, so transesophageal probe can be used to pace atrium)
- Tachycardia termination can be achieved by overdrive pacing at a rate approximately 20% faster than flutter cycle length
Why doesn’t adenosine work in flutter?
Macro reentrant circuit doesn’t involve the AV node, so giving adenosine (which blocks the AV node) won’t terminate the tachycardia
How is adenosine helpful in flutter?
It can help if diagnosis is unclear… will block the AV node and bring out the flutter waves
True or False: Atrial flutter in infants with structurally normal hearts usually occurs as an isolated event?
True
What are atrial flutter rates in newborns?
Vary between 300-450bpm (with variable AV conduction)
True or False: Once atrial flutter is terminated, it doesn’t usually recur in newborns with structurally normal hearts?
True
*Long term treatment with antiarrhythmics isn’t usually needed and reserved for patients with recurrent flutter
How can adenosine help diagnose flutter in an infant with narrow complex tachycardia?
Helps to unmask flutter waves by blocking the AV node and making the flutter waves more visible
