PREP 2022 Flashcards
Absent pulmonary valve syndrome is most commonly associated with what?
ToF
Absent pulmonary valve syndrome occurs in what % of ToF?
2.5%
True or False: In absent pulmonary valve syndrome, there can be complete absence of pulmonary valve tissue or a small ridge of tissue at the valve annulus which is often hypoplastic?
True
What is the presentation of absent pulmonary valve syndrome?
Varies widely from minimal symptoms to respiratory distress/failure
What causes respiratory distress in absent pulmonary valve syndrome?
Proximal and/or distal bronchial compression
What can be done to improve respiratory distress in absent pulmonary valve syndrome?
-Prone position (reduces bronchial compression by the PAs and decreases ventilation/perfusion mismatch)
-Intubation/PPV for patients with persistent respiratory distress
How can ToF absent PV syndrome result in cyanosis?
R-L shunting at the VSD
True or False: Patients with ToF absent PV syndrome are dependent on unrestrictive mixing at the atrial level?
False
The absence of what is hypothesized to be associated with the development of absent pulmonary valve syndrome?
PDA (only rare cases where absent pulmonary valve syndrome develops with the presence of a PDA)
Respiratory distress in ToF absent PV syndrome is often the result of what?
Dilated pulmonary arteries causing bronchial compression
What can help to decrease ventilation/perfusion mismatch in ToF absent PV syndrome?
Prone positioning (moves that PAs off the airway to decrease bronchial compression)
*Patients with persistent respiratory distress may require intubation and PPV
How is the RP relationship determined?
-Draw a line at the midway point between 2 R waves
-If the P wave falls in the first half of the RR interval, it is short RP tachycardia
-If the P wave falls in the second half of the RR interval, it is long RP tachycardia
What is the differential diagnosis for a long RP tachycardia?
-Atrial ectopic tachycardia
-PJRT
-Atypical AVNRT
-Sinus tachycardia
Describe the P-waves in PJRT
Deeply negative in the inferior leads (II, III, aVF)
Describe the P-waves in sinus tachycardia?
-Normal P-wave axis and morphology (positive in I and aVF)
Long RP tachycardia with low-amplitude P waves and a biphasic P-wave in lead I… most likely etiology?
EAT- Long RP tachycardia with abnormal P-waves, but not PJRT (P-waves would be negative in II, III, aVF)
True or False: Patients with EAT can have incessant tachycardia?
True- Rate may not be significantly elevated and patients can be asymptomatic delaying diagnosis…. longer duration of tachycardia before diagnosis, greater risk of patient developing tachycardia induced cardiomyopathy
What should be done before treating EAT?
Echo- need to assess for structural abnormalities and ventricular dysfunction
What is the typical first line therapy for EAT if function is preserved?
B-blockers
After beta-blockers, what are the next medications used for EAT?
-Sotalol or Flecainide
-Amiodarone as a 3rd line agent
Besides antiarrhythmics, what can be done to treat EAT?
Ablation- Potentially curative with high success rates and low complication rates
*Should be considered 1st line if patient is adequate size (and if there is ventricular dysfunction)
Describe the RP relationship in SVT due to WPW and typical AVNRT
Short RP
What is the differential diagnosis for long RP tachycardia?
-EAT
-PJRT
-Atypical AVNRT
-Sinus tachycardia
Patients with incessant atrial tachycardia are at risk of developing what?
Tachycardia induced cardiomyopathy (more common when HR isn’t significantly elevated)
Failure to thrive, macroglossia, mild respiratory distress, cardiomegaly, hepatomegaly, mild generalized hypotonia, elevated CK and transaminases?
Classic infantile-onset Pompe
In classic infantile-onset Pompe disease, enzyme assay will shoe a severe deficiency of what?
Acid alpha glucosidase
What is a lysosomal storage disorder characterized by deficiency or complete absence of the lysosomal enzyme, acid alpha glucosidase (GAA)?
Pompe
-Also known as glycogen storage disease type II or acid maltase deficiency
What causes Pompe disease?
Autosomal recessive mutation of the GAA gene on chromosome 17q25
What does deficiency of acid alpha glucosidase result in?
Accumulation of glycogen in lysosomes and cytosol of target organs (skeletal muscle, cardiac muscle, liver)
How does Pompe disease present?
Wide spectrum of disease manifestations that vary in time of clinical onset, severity of symptoms, rapidity of disease progression and overall prognosis
What does the disease severity in Pompe correlate with?
Amount of residual GAA (alpha glucosidase) activity
How is Pompe disease calssified?
-Infantile onset
-Late onset
*According to age of initial clinical presentation
When and how does classic infantile Pompe disease usually present?
-1st 2 months of life
-Generalized hypotonia, cardiomegaly, respiratory distress, feeding difficulties, failure to thrive
What is the characteristic cardiac finding in Pompe patietns?
HCM
What causes HCM in Pompe patietns?
Deposition of glycogen into the myocardium
Besides HCM, what other cardiac findings can be seen in Pompe disease?
LVNC
What is often seen on echo in Pompe patients?
LVOTO due to HCM
What is seen on ECG in Pompe disease?
-Short PR interval
-Tall QRS complexes with increased voltages
-Increased QT dispersion
What is often seen in a later stage of infantile Pompe disease?
Progressive dilation of the ventricle
What is the natural history of Pompe disease if left untreated?
Death by 1-2 years due to cardiorespiratory failure
Patients with classic infantile Pompe disease that what % of residual GAA (alpha glucosidase) activity?
<1%
How does non-classic infantile Pompe disease present?
1st year after birth, but is associated with less severe cardiomyopathy and slower disease progression
How does late-onset Pompe disease present?
-Any time after infancy as a progressive skeletal myopathy
-Typically not associated with any cardiac manifestations
-Enzyme assay with 4-40% of residual GAA (alpha glucosidase) activity
What is the specific treatment for Pompe disease?
-Enzyme replacement therapy using recombinant human GAA (alpha glucosidase)… has been available since 2006
True or False: In infantile Pompe disease, early institution of enzyme replacement therapy has been shown to decrease LV mass, improve skeletal muscle function and prolong overall survival?
True
True or False: In infantile Pompe disease, early institution of enzyme replacement therapy improves LV voltages, QT dispersion and PR intervals on ECG?
True
True or False: In late-onset disease, enzyme replacement therapy has been shown to slow the progression of muscle weakness?
True
True or False: Pompe disease is on the newborn screening protocol in many states?
True (since 2015)
When is the best time to initiate enzyme replacement therapy in infantile Pompe disease?
First few days after birth
Severe aortic root dilation is commonly seen in what?
Connective tissue disorders like Marfan
True or False: It would be quite unusual to see a dilated LV with severely decreased LV function in the early phase of infantile Pompe?
True- can be seen at a later stage in classic infantile Pompe disease when the ventricular function deteriorates and the heart dilates
True or False: Pericardial effusion is not specifically associated with infantile Pompe disease?
True
What is a glycogen storage disorder caused by a deficiency or complete absence of lysosomal acid alpha glucosidase?
Pompe
How does classic infantile Pompe disease present?
Rapidly progressive entity manifesting in early infancy with hypotonia, HCM and respiratory distress
What is essential for survival beyond infancy in classic infantile Pompe disease?
Prompt diagnosis and initiation of enzyme replacement therapy with recombinant human acid alpha glucosidase
True or False: Late-onset Pompe disease isn’t typically associated with cardiac manifestations?
True
What is normal velocity flow in the ductus arteriosus on a fetal echocardiogram?
0.6-1.4m/sec
What is the size of the ductus arteriosus equivalent to in fetal life?
Pulmonary trunk and descending aorta
True or False: In fetal life, the ductus arteriosus carries the majority of the fetal RV output into the descending aorta?
True
Depending on gestational age, what % of the RV output actually flows into the developing lungs?
10-25%
How is ductal patency maintained during fetal life?
Regulatory action of prostaglandins, nitric oxide, and low fetal O2 saturations
What causes premature ductal constriction in a fetus?
-Extrinsic agents: NSAIDS like indomethacin or herbal supplements
-Idiopathic
*Uncommon and often underrecognized, but can have bad consequences
What is the result of prenatal ductal constriction and ductal closure?
-Acute increase in fetal RV afterload
-Results in RVH, TR, RAE and increase R-L shunting across the foramen (depends on severity of ductal constriction)
-Increased pressure in pulmoanry vessels can cause dilation of MPA and branches with PS, PI or pulmonary vascular disease (thickening of media of pulmonary arterioles in response to obligatory increased flow to lung parenchyma)
-Severe cases- progressive RV failure resulting in hydrops fetalis and fetal demise
What is the most common echo finding in premature ductal constriction?
Disproportionate RVH
What are some findings on fetal echo in premature ductal constriction?
-Disproportionate RVH (most common)
-Ductus arteriosus narrow (much smaller than adjacent pulmonary trunk)
-Color Doppler with high-velocity jet across ductus arteriosus into descending aorta
-PI <1.9
-RV dilation
-TR
-Right heart failure
What is the pulsatility index?
-Measure of resistance to flow
-Peak systolic velocity-End diastolic velocity/Mean velocity
What is the normal range of pulsatility index for the ductus arteriosus?
1.9-2.5
In the presence of ductal constriction, what is the pulsatility index?
<1.9
What findings on fetal echo predict imminent fetal hydrops?
-Prominent reversal in ductus venosus flow with atrial contraction
-Presence of umbilical venous pulsations
What should be done if ductal constriction is seen on fetal echo?
-Close serial follow-up
-Maternal history to assess for possible causes (NDAIDS, etc) and discontinue is able
-Consider delivery with worsening RV function and impending hydrops (after birth PVR drops and decreases RV afterload)
What do the postnatal manifestations and overall outcome of ductal constriction in utero depend on?
Severity, duration and gestational age at onset
True or False: Ductal constriction is rare prior to 27 weeks gestation and the risk increases with advancing gestational age?
True
What are postnatal symptoms of ductal constriction?
-Mild cyanosis
-PPHN
-Severe respiratory distress
-Neonatal death
What may be needed postnatally for an infant with ductal construction?
-Close monitoring
-O2
-Pulmonary vasodilators
-Ventilator support
-ECMO
True or False: In some instances, fetal ductal closure is diagnosed postnatally in a cyanotic neonate with disproportionately thickened RV, R-L shunt at atrial level and absent ductus arteriosus within 24 hours of birth?
True
What is the result of premature constriction and closure of the fetal ductus arteriosus?
Acute increase in the RV afterload in the fetus
*Severe cases, progressive RV failure resulting in hydrops and fetal demise
What are the key echo findings in premature ductal cosntriction?
Disproportionate RVH, narrow ductus arteriosus with accelerated flow, ductal PI of <1.9
What can occur postnatally due to premature ductal construction?
-Mild cyanosis
-PPHN
-Severe respiratory distress
-Neonatal death
*Depends on the degree, duration and developmental stage at onset of ductal constriction
What are the major Jones criteria for acute rheumatic fever in the low-risk population?
-Carditis: Clinical or subclinical
-Polyarthritis
-Syndenham chorea
-Erythema marginatum
-Subcutaneous nodules
What are the minor Jones criteria for acute rheumatic fever in the low-risk population?
-Polyarthralgia
-Fever (>38.5C)
-ESR >60 and/or CRP >3
-Prolonged PR interval (unless carditis is a major criterion)
What is required to diagnose acute rheumatic fever?
2 major
1 major + 2 minor
Evidence of preceding strep infection
Rheumatic carditis is seen in what % of acute rheumatic fever cases?
40-70%
Where is the inflammation in rheumatic carditis?
All layers of the heart (pancarditis)
What is the predominant feature in rheumatic carditis?
Valvulitis
What is the most common cardiac manifestation of acute rheumatic carditis?
-MR (occurs in 95% of cases)
-Then AI (20% with MR and 5% isolated AI)
What is the clinical presentation of rheumatic carditis?
Ranges from asymptomatic murmur to acute severe heart failure
What is often an early sign of carditis?
Tachycardia
Describe the murmur of MR that can be seen in carditis due to acute rheumatic fever?
-High-pitched
-Holosystolic
-Cardiac apex with radiation to the axilla
-Often soft (even if significant regurgitation)
-May hear a middiastolic rumbling murmur of relative MS (Carey-Coombs murmur)… but isolated MS doesn’t occur in acute rheumatic carditis
True or False: In carditis due to acute rheumatic fever, mild MR often resolves whereas moderate to severe MR often progresses to chronic rheumatic heart disease?
True
What is the most common valvular lesion in adults with chronic rheumatic heart disease?
Mitral stenosis
*Can initially have MR that improves with subsequent development of MS many years later
*AS is another late sequelae of rheumatic fever, occurring 20-30 years after the acute episode
Describe the murmur heard with isolated AI
-Soft
-Early diastolic
-Decrescendo
*Isolated AI can occur with acute rheumatic carditis, but isn’t the most common manifestation
How is rheumatic carditis classified?
Pancarditis, but is predominantly a valvulitis
What is the most common valvular abnormality in acute rheumatic fever?
MR
What is the natural history with mild MR in acute rheumatic fever?
Often resolves
What is the natural history with moderate-severe MR in rheumatic heart disease?
Often progresses to chronic rheumatic heart disease
Describe what happens in a double chambered RV?
-Perimembranous VSD and development of obstructive RV muscle bundles
-Leads to a higher-pressure RV proximal to the RV muscle bundles and a lower-pressure RV distal to the RV muscle bundles
-Proximal portion of RV has a high RV pressure (and high TR jet gradient and low VSD gradient)
-There will be a high gradient across the RV muscle bundle
-PV is usually normal and there will be no significant additional gradient across the pulmonary valve
-PA pressure is normal
When does double-chambered RV usually present?
-Infancy or childhood
-Can be diagnosed in adults
Double-chambered RV is frequently associated with what other form of congenital heart disease?
Perimembranous VSD (90% of cases)
*VSD may not be seen in a patient with isolated double chambered RV, but there may have been a VSD that closed spontaneously
What is often seen in association with a VSD and double-chambered RV?
Subaortic membrane
What other forms of CHD is double chambered RV associated with?
-Perimembranous VSD
-Subaortic membrane
-ToF
-Ebstein
-DORV
-Single ventricle variants
-Other forms of CHD
Describe the development of double chambered RV from a pathological perspective
-Progressive hypertrophy of anomalous RV muscle located below (proximal to) the infundibular septum
-Includes hypertrophy of the crista supraventricularis, trabecular tissue, or moderator band
What causes double chambered RV?
-Abnormal blood flow patterns within RV may lead to abnormal RV muscular hypertrophy
-Often develops as a perimembranous VSD decreases in size- possibly due to higher flow gradient across the VSD entering the RV body and anomalous RV muscle bundles
-Also may be that VSD becomes smaller or closes spontaneously as adjacent anomalous RV muscle bundles hypertrophy with increasing gradient/obstruction from the double chambered RV
-Can also develop in patients who have undergone surgery for VSD closure
What do the symptoms associated with double chambered RV depend upon?
Degree of obstruction and presence of associated congenital heart abnormalities
What are some of the possible symptoms associated with double chambered RV?
-Exercise intolerance
-Dyspnea
-Syncope
-Chest pain
-Arrhythmias
-Combination
*Most children are asymptomatic
What has been reported in patients with unrepaired double chambered RV that can lead to acute symptoms caused by a sudden increase in the obstruction?
Endocarditis
What are some of the physical exam findings seen in double chambered RV?
-SEM without a valve click (differentiates from RV obstruction from valvar PS)
-RV heave or thrill (if moderate to high gradient and if RV proximal to level of obstruction is significantly hypertrophied)
What is seen on ECG in double chambered RV?
RV hypertrophy
How is double chambered RV diagnosed?
-Children: Echo is usually sufficient (subcoastal or parasternal RV inflow-outflow imaging
-Adults: May need TEE, CT, MRI, cath or combination
What is done for surgical repair of double chambered RV?
-Resection of abnormal RV muscle, usually through the TV
-Presence of any associated cardiac abnormalities (VSD, etc. should be evaluated and addressed at the same time)
When is surgical repair of double chambered RV indicated?
-Peak pressure >40mmHg within RV body
-Increasing gradient
-Evidence of cardiac-related symptoms
True or False: Surgical repair of uncomplicated double chambered RV is highly successful with low morbidity and morality?
True- Reoperation for recurrent double chambered RV is unusual when there has been adequate surgical relief of RV obstruction
True or False: Transcatheter intervention via balloon angioplasty or stent placement is not usually successful as definitive repair of double chambered RV, but it has been performed in patients who are at high surgical risk?
True
Double chambered RV is most commonly seen in what patients?
Young patients in association with a restrictive perimembrnaous VSD
True or False: Most children with double chambered RV are asymptomatic?
True
When is surgical repair via resection of abnormal RV muscle bundles indicated for double chambered RV?
-Gradient greater than 40mmHg across the anomalous RV muscle bundles
-Presence of symptoms
-Associated anomalies that warrant surgical intervention
What is important as part of screening for adults with repaired CoA?
3D imaging
How often should an adult with repaired CoA have 3D imaging?
Every 5 years or less (depending on complexity of case)
Besides re-coarctation, what is a risk in patients who have undergone repair of coarctation?
Aneurysm at site of prior repair
Which patients with repaired CoA and are at increased risk for aneurysm at site fo repair?
Those who have undergone a polyethylene terephthalate (Dacron) graft repair
What is often required to diagnose an aneurysm in an adult with repaired CoA?
3D imaging via CT or MRI (echo can often miss large aneurysms)
Besides screening for aneurysm at the site of a CoA repair, what else is CTA or MRI helpful for in these patients?
Assessment of the size of the ascending aorta (especially if the patient has a bicuspid aortic valve)
Current guidelines suggest surgical intervention for aneurysm of the ascending aorta once it is above what measurement?
> 5-5.5cm
What surgical approach is an option for patients who have a large ascending aortic aneurysm, but a well- functioning aortic valve (even if bicuspid)?
Valve-sparing aortic root replacement
What is a big problem for patients who have undergone CoA repair (especially in those whose repair happens outside of infancy?
HTN
Persistent HTN may predispose someone with repaired CoA to what?
Early atherosclerotic heart disease
*Need to try to achieve goal directed medical therapy
All adults with repaired CoA should undergo what to evaluate for aneurysm or re-coarctation at least every 5 years?
3D imaging of aorta
What are options for 3D imaging of the aorta?
CT or MRI- Echo is helpful as a screening tool, but isn’t good to detect things like aneurysm (especially in repaired CoA patients)
What is a common problem in patients who have undergone repair of CoA?
HTN- Treatment needs to be aimed at goal-directed medical therapy
True or False: Routine stress tests are part of the follow-up assessment of patients who have CoA?
False
What is in the differential diagnosis for new-onset LV dilation and systolic dysfunction in a teenager?
-CHD
-Cardiomyopathy
-Myocarditis
-Athletes heart
What should be assessed during history for a teenager with new-onset LV dilation and systolic dysfunction?
-Recent viral illness (myocarditis)
-Palpitations (tachyarrhythmia-induced cardiomyopathy)
-Chest pain or syncope with exertion (coronary anomaly)
-Exercise intolerance
-Family history: Inherited forms of cardiomyopathy (dilated, arrhythmogenic, hypertrophic, LVNC) or CHD
In pediatrics, athlete’s heart is most often encountered in patients with what?
LVH and a questionable diagnosis of HCM
True or False; Athlete’s heart can overlap with other cardiomyopathies (DCM, arrhythmogenic cardiomyopathy, myocarditis)?
True
True or False: Exercise-induced cardiac remodeling manifests differently in athletes in endurance v. strength training?
True
Describe the exercise-induced cardiac remodeling seen in endurance athletes
-Volume overload during sustained high cardiac output
-Biventricular dilation
-Biatrial enlargement
-Low normal resting EF
-Mild-moderate eccentric LVH
What causes the eccentric hypertrophy seen in endurance athletes?
New sarcomeres are added in series to existing sarcomeres leading to volume overload-induced cardiac hypertrophy
*Distinct from pathologic hypertrophy in hypertrophic cardiomyopathy
True or False: There are dilation volume cutoffs for the LV and RV which reliably differentiate between physiologic v. pathologic heart dilation?
False- Unless the heart is markedly dilated
True or False: As little as 3-5 hours of exercise per week and >5 hours of exercise are associated with a high proportion of adults outside published normal ranges for both hypertrophy and dilation?
True
True or False: In athletes, EFs are often lower than one would expect at rest given dilation of the LV?
True
What is one way to distinguish a low-normal EF as being due to athletic status v. pathology?
Exercise test
-Athletes wouldn’t have exercise intolerance would probably have supranormal results on exercise testing without inducible arrhythmia
-Imaging at rest would show normal diastolic parameters
-Exercise imaging can show normalization of cardiac function
Athlete’s heart is a diagnosis of…
Exclusion (due to heightened awareness of SCD in young athletes)
*Need to consider athlete’s heart when factoring in exercise restriction… athletes with no pathologic disease can affect quality of life and economic opportunities
What can be done to distinguish between athletes heart and cardiomyopathy?
-Period of deconditioning (3-6 months) to see if parameters normalize
-If they don’t, findings are consistent with cardiomyopathy v. athlete’s heart
What are some forms of CHD that may be associated with ventricular dilation and decreased function over time?
-L-R shunt lesions (ASD, VSD, PDA, AVM)
-L obstructive lesions (CoA)
-LV volume overload (valvulopathy)
-Coronary anomalies
*These will often have associated PE findings except coronary anomalies
*Most picked up by echo, may need MRI or CT for something like sinus venosus ASD, coronary anomalies, aortic arch issues, etc
True or False: Findings of athlete’s heart can overlap with the various cardiomyopathies?
True- Dilated, hypertrophic, ARVC, myocarditis
Which form of heterotaxy has associated twin AV nodes and SVT
Right atrial isomerism
Which form of heterotaxy has associated complete heart block and bradyarrhythmias?
Left atrial isomterism
True or False: All patients with heterotaxy syndrome are at risk for both tachy and bradyarrhythmias?
True
What is the differential diagnosis when there is a change in QRS morphology on ECG?
-Intermittent preexcitation
-Aberrant conduction
-Ventricular rhythm
-Twin AV nodes
What is suggested when there is a change in QRS morphology always preceded by a change in the P-wave morphology?
Twin AV nodes
*When the atrial impulse occurs from one site, it conducts down the close AV node
*When the atrial stimulus occurs from a different site closer to the other AV node, conduction changes to that second AV node
What are clues that change in QRS morphology is due to intermittent preexcitation?
-Usually no change in P-wave morphology that precedes each change in QRS morphology
-Beats that are preexcited would have the characteristics of preexcitation (short PR, wide QRS, delta wave)
What can occur with premature atrial beats that come at a time when one of the bundles is refractory?
Aberrant conduction
What is rate-related aberrancy?
As the HR increases one of the bundles is refractory and not able to conduct
What situations can result in aberrancy?
Acidosis
Electrolyte abnormalities
*QRS complex would gradually change not be a beat to beat difference
True or False: There is usually not a change in P-wave morphology with aberrant conduction?
True
What is the differential diagnosis for a change in QRS morphology?
-Intermittent preexcitation
-Aberrant conduction
-Ventricular rhythm
-Twin AV nodes
What is the differential diagnosis of a wide QRS tachycardia?
-Ventricular rhythm (v-tach, torsades)
-Supraventricular rhythm with aberrancy (sinus tachycardia with underlying BBB or pre-excitation, SVT with aberrancy)
-Antidromic supraventricular tachycardia
-Artifact
How can you distinguish sinus rhythm with artifact?
-See if QRS complexes can be detected within the artifact recording… will see narrow QRS complexes marching through the time of the artifact at a rate similar to what was seen before/after artifact
-Can also look at other leads as well
What is considered a toxic digoxin level?
> 2ng/mL
Generalized ST segment depression, T-wave inversion, accelerated junctional rhythm with atrioventricular block, curved sagging of ST segments?
Digoxin overdose
True or False: Digoxin toxicity can cause nearly every possible arrhythmia?
True
What are some arrhythmias that are more suggestive of digoxin toxicity?
-New-onset AV block
-Accelerated junctional rhythm with or without high-degree AV block
-Nonparoxysmal atrial tachycardia with AV block
-Bidirectional ventricular tachycardia
What will happen if digoxin toxicity is not promptly recognized and treated?
-Ventricular fibrillation
-May not be responsive to defibrillation
What is lifesaving in cases of digoxin toxicity?
Digoxin-specific antibody fragements
What can be given for ventricular tachyarrhythmias due to digoxin toxicity?
Lidocaine or phenytoin (while awaiting digoxin antibodies)
What can be given for bradyarrhythmias due to digoxin toxicity?
Atropine (while awaiting digoxin antibodies)
What are common symptoms seen in digoxin toxicity?
GI- Diarrhea and vomiting
What lab abnormality is seen in digoxin toxicity?
Hyperkalemia (indicative of severe digoxin toxicity)
How does digoxin toxicity cause hyperkalemia?
-Blocks the sodium and potassium adenosine triphosphatase pump
-Results in increased extracellular potassium that causes hyperkalemia
What lab derangement can occur once antidigoxin antibodies are given for digoxin toxicity?
Hypokalemia- requires prompt correction
Coadministration of what results in an increase in serum digoxin levels?
Amiodarone
How is digoxin excreted?
Via kidneys through glomerular filtration and active tubular secretion
Why does amiodarone result in increased serum digoxin levels?
It likely inhibits renal tubular secretion of digoxin
What needs to be done to the digoxin dose in patients who are concomitantly using amiodarone?
Lower by 50%
*Need to monitor digoxin levels carefully
What can happen if amiodarone is started without lowering digoxin dose?
Digoxin toxicity
An increase in what lab value may result in increased digoxin levels?
Creatinine- Digoxin is excreted by the kidneys, reduced kidney function could increase levels
The ingestion of what dose of digoxin by a child without underlying heart disease can result in serious toxic effects?
0.3mg/kg
True or False: Measurement of serum digoxin concentrations in kids doesn’t always correlate with toxic effects?
True- Need a high index of suspicion and familiarity with the clinical signs and ECG changes
True or False: Once antidigoxin antibodies are administered, serum digoxin levels can’t be relied on and a 2nd dose may be needed after 12 hours based solely on clinical findings?
True
When should extracorporeal cardiopulmonary resuscitation be considered?
In refractory cardiac arrest for select populations (children with heart disease) with a witnessed in-hospital cardiac arrest in settings with adequate systems and resources to use ECPR effectively
True or False: On the basis of current studies, there is insufficient evidence to recommend consideration of extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest?
True
*Indications rapidly evolving and individual patients considerations should be discussed with the responsible ICU, ECMO and surgical teams before determining any specific patient’s eligibility
Can patients in the ICU for noncardiac conditions with witnessed arrest be considered for extracorporeal cardiopulmonary resuscitation?
Yes… but patients with things like septic shock are unlikely to receive adequate flow/supports through peripheral cannulation and would have less favorable outcomes (unless surgeon would do central cannulation)
What does extracorporeal cardiopulmonary resuscitation involve?
Adjunctive use of mechanical cardiopulmonary support to assist during or immediately after cardiopulmonary resuscitation
When should extracorporeal cardiopulmonary resuscitation be considered?
In refractory cardiac arrest for select populations (children with heart disease) with a witnessed in-hospital cardiac arrest in settings with adequate systems and resources to use ECPR effecitvely
What are commonly used benzodiazepines in pediatric cardiac patients?
-Lorazepam
-Diazepam
-Midazolam
How do benzodiazepines work?
Bind to the GABA (y-aminobutyric acid) A receptors, mostly in the CNS, and hyperpolarizing them to be more responsive to GABA inhibition
-Leads to sedation, anxiolysis and decreased excitability
What are the effects of benzodiazepines?
Sedation, anxiolysis, decreased excitability
What causes the cardiac effects of benzodiazepiens?
Combination of reduced sympathetic activity caused by sedation and reduced parasympathetic stimulation in response to GABA activation in the nucleus ambiguus and reduced vagal tone
What are the cardiac effects of benzodiazepines?
-Depends on dose
-Hypotension
-Bradycardia or tachycardia: Attributable to reduction in sympathetic stimulation or overinhibition of parasympathetic outflow and baroreceptor reflex stimulation by lowered BP
-Direct negative inotropic effect on myocardial contractility (due to Ca channel suppression in the SR)
True or False: Benzodiazepines are generally well tolerated at low doses?
True
True or False: Benzodiazepines have been directly implicated in acute CV collapse and cardiac arrest (mostly at high doses), in rapid IV bolus, or in neonates/patients with cyanotic CHD?
True- Use with caution
What is a benzodiazepine antagonist?
Flumazenil
How does flumazenil work?
Competitive inhibition at the benzodiazepine-binding site on GABA receptors
*Used as an antidote in benzodiazepine overdose
What causes the cardiac effects of flumazenil?
Increased sympathetic stimulation with benzodiazepine reversal
What are the cardiac effects of flumazenil?
-Tachycardia
-Ventricular ectopy
-SVT
*Older adults, can see complete heart block and spontaneous cardiac arrest, but not understood why this happens
What happens to patients that receive flumazenil?
-Transient increase in circulating epinephrine and norepinephrine
-Results in increased HR, BP, PA pressure, wedge pressure and LVEF
-No significant increase in CVP
What are the non-cardiac effects of flumazenil?
-Seizures or status epilepticus (can be fatal)
-Anxiety
-Agitation
Which patients have the most concerning side effects from flumazenil?
Those with longstanding benzodiazepine dependence (seizures and status epilepticus which can be fatal)
What can happen if a patient has had a large dose of benzodiazepine and was then given flumazenil?
Can develop rebound sedation after antagonistic effects of flumazenil wear off
What causes benzodiazepines effects on cardiac activity?
-Reduced parasympathetic outflow (reducing vagal tone)
-Reduced sympathetic stimulation
-Direct myocardial suppression
What are benzodiazepine antagonist effects on cardiac activity attributable to?
Increased sympathetic outflow causing a transient increase in circulating epinephrine and norepinephrine levels
True or False: Benzodiazepines and their antagonists must be used with extreme caution in patients with cyanotic CHD, neonates and those with abnormal cardiac function?
True
Grade 2/6 systolic murmur along the left sternal border that becomes louder when rising from a crouched position?
LVOT murmur (think HOCM)
What are some ECG findings consistent with HOCM?
-Sinus bradycardia
-Pronounced ventricular hypertrophy by voltage
-T-waves in precordial leads with a strain pattern
What is the Sokolow-Lyon criteria for ventricular hypertrophy?
Sum of the R wave in V6 and S wave in V1 >35mm
True or False: LVH on resting ECG has a low sensitivity/specificity and PPV for LVH?
True
What should you consider for an ECG with deep S wave in V6, tall R wave in V1 and t-wave inversion in the lateral leads?
-Pulmonary HTN
-PS
-Other pathologies involving RV and outflow tract
What is the modified Bernoulli equation?
Pressure Gradient (mmHg) = 4V2 (V = peak velocity)
In the modified Bernoulli equation, what is ingored?
The proximal velocity- ignored if it is <1 M/sec
*When a fixed or dynamic proximal gradient is present, the accelerated velocity must be factored into the equation
True or False: In the setting of severe multilevel obstruction, the presence of 2 stenoses in series may make it impossible to ascertain the precise individual contribution of each by echo?
True
Which tends to be higher, Doppler peak gradients or peak-to-peak cath gradients?
Doppler peak gradients
What constitutes mild pulmonary valve stenosis?
Peak velocity <3M/sec
Peak gradient <36mmHg
What constitutes moderate pulmonary valve stenosis?
Peak velocity 3-4M/sec
Peak gradient 36-64mmHg
What constitutes severe pulmonary valve stenosis?
Peak velocity >4M/sec
Peak gradient >64mmhg
An RV pressure of what % systemic is consistent with moderate pulmonary stenosis?
50-75%
True or False: Severity of PS using Doppler derived gradients has demonstrated a reasonable correlation between peak-to-peak gradients obtained by catheterization?
True
How can you calculate pressure decrease across a stenotic semilunar valve by echo?
Peak velocities obtained from CW Doppler signals across a stenotic semilunar valve are converted into a pressure gradient by the modified Bernoulli equation
What are other names for a doubly committed juxta-arterial VSD?
-Subpulmonary
-Supracristal
-Subarterial
Where is a double committed juxta-arterial VSD seen on a short axis view on echo?
-Proximal to the pulmonary valve and more distal from the tricuspid valve
*Perimembranous VSD are seen in close proximity to the tricuspid valve
What can be used to estimate the pressure gradient between the right and left ventricles in patients with VSDs?
CW Doppler
How do you estimate the pressure gradient between the RV and LV in a patient with a VSD?
*Doppler measurement of peak velocity across defect
*Convert to pressure gradient using modified Bernoulli equation (P = 4V2
*Subtract pressure gradient from patient’s SBP to estimate RVSP and PA pressure
True or False: In the absence of RVOTO, smaller VSDs are nearly always associated with restrictive hemodynamics?
True- High velocity and high peak trans-septal gradient with low estimated RV pressures
What type of VSDs tend to demonstrate unrestrictive hemodynamics?
Large VSD
*Low velocity and low peak trans-septal gradient with elevated estimated RV pressures
What causes a doubly committed juxta-arterial VSD?
Absence of the subpulmonary infundibulum (this normally serves to lift the pulmonary trunk away from the base of the heart)
*Results in fibrous continuity between the aortic and pulmonary valves
What can happen to the aortic valve in a doubly committed juxta-arterial VSD?
Risk for aortic valve leaflet prolapse (most commonly the right coronary cusp) due to deficiency of muscular support
What should be done for a small, restrictive, doubly committed juxta-arterial VSD?
-Supportive care
-Routine follow-up to assess for future evidence of aortic valve prolapse or AI
What information does Spectral Doppler provide about VSD hemodynamics?
Characterizes restrictive v. nonrestrictive based on the peak velocity by using the modified Bernoulli equation to estimate peak trans-septal pressure gradients
Why do doubly committed juxta-arterial VSDs need to be monitored so closely?
Risk for AV prolapse
What defines critical PS?
Ductal dependence to maintain adequate pulmonary blood flow
What is the treatment of choice for valvar PS?
Pulmonary balloon valvuloplasty
What might be needed following pulmonary balloon valvuloplasty?
PGE
Why might an infant need PGE following pulmonary balloon valvuloplasty?
RVH associated with poor compliance and a hyperdynamic infundibulum can result in preferential R-L atrial shunting of systemic venous return and a reduced RV output
What can be given after pulmonary balloon valvuloplasty to improve diastolic filling of the noncompliant, hypertrophied and potentially hypercontractile RV?
Beta blockade
How does beta blockade help after pulmonary balloon valvuloplasty?
-Reduces HR
-Reduces contractility
-Improves diastolic filling
*This can promote antegrade flow across the pulmonary valve
What kind of receptors are beta-adrenergic receptors and where are they located?
-Transmembrane guanine nucleotide (G) protein-coupled receptors
-Located on the cardiac sarcolemma
What activates B-adrenergic receptors?
-Norepinephrine
-Epinephrine
-Catecholamines
Stimulatory (Gs) proteins link G-protein coupled receptors to what, which then produces what?
-Adenylyl cyclase
-Cyclic adenosine monophosphate (cAMP) from adenosine triphosphate
How do inhibitory (Gi) protein receptors inhibit the production of cAMP?
Deactivate adenylyl cyclase
What does cAMP activate that results in an increase in the rate/force of myocardial contraction through the opening of Ca channels and increase in myocardial relaxation through increased reuptake of Ca?
Protein kinase A pathway
How does Gs protein receptor stimulation affect conduction?
-Accelerates rate of conduction
-Gs protein receptor stimulation within the conduction system increases the pacemaker current within the sinus node… accelerates rate of conduction
What interrupts the link between G-protein coupled receptors and adenylyl cyclase resulting in decreased contractility and HR?
Muscarinic stimulation of Gi protein receptors after vagal activation
What improves with a reduction in HR?
Filling time- there is an increase in the amount fo time spent in diastole during the cardiac cycle
Where are B1 adrenergic receptors found?
Heart
Where are B2 adrenergic receptors found?
Bronchial and vascular smooth muscle
What do B-blockers result in?
-Reduction in rate/force of myocardial contraction
-Reduction in pacemaker current and rate of conduction
What is the difference between first, second and thirs generation B-blockers?
-First generation are nonselective for B1/B2 blockade
-Second generation have a relative selectivity for B1
-Third are nonselective with additional benefits like alpha-blocking activity
Propranolol and nadolol are what generation B-blocker?
1st
Metoprolol, atenolol and esmolol are what generation B-blocker?
2nd
Carvedilol is what generation B-blocker?
3rd
What are 2 proposed mechanisms for Beta-blockers decreasing BP?
-Reduced CO
-Blockade of B-receptors within the renal juxtaglomerular complex (reduces circulation levels of renin)
What causes the reduction in myocardial O2 demand for patients taking a B-blocker?
-Reduction in HR and BP
-Limiting increases in contractility that result from exercise or agitation
What are the effects of B-blockers on the heart?
-Reduction in rate and force of myocardial contraction
-Reduction in pacemaker current and rate of conduction
Elevated partial pressure of PCO2 with proportionately low pH?
Acute respiratory acidosis without compensation
In acute onset respiratory acidosis, the pH decreases by 0.08 for every _mmHg increase in PCO2 above normal (40mmHg)?
10
In the case of chronic respiratory acidosis (>72 hours), metabolic compensation with an increase in serum bicarbonate is predicted by what formula?
3.5 * (change in PCO2/10)
What type of ventilation is optimal for Glenn circulation and why?
-Negative pressure
-Extubated
-Spontaneous breathing
-SVC blood return to the pulmonary vasculature is passive
What are the effects of mild hypercapnia (PCO2 45-55mmHg) on Glenn physiology?
-Leads to cerebral vasodilation
-Leads to increased cerebral blood flow
-May improve perfusion through the Glenn circulation
Giving what can improve metabolic acidosis or a pulmonary HTN crisis?
NaBicarb
If a patient doesn’t have adequate ventilatory capacity, giving what can worsen hypercapnia and acidosis, potentially leading to pulmonary vasoconstriction?
Bicarb
What should be done to the ventilator settings if the lungs are overinflated or there is inadequate exhalation (like in bronchospasm)?
Decrease PEEP
Worsening compliance can lead to what metabolic derangement?
Respiratory acidosis
What should always be considered in cases of respiratory acidosis?
Malpositioned ET tube
Permissive hypercapnia up to what improves pulmonary blood flow in the Glenn circulation?
55mmHg
*But hypercapnia leading to acidosis may also trigger pulmonary vasoconstriction
What defines tricuspid atresia?
-Cyanotic CHD
-Complete absence of tricuspid valve, obligate R-L atrial level shunting, hypoplasia of RV
What do the clinical features in tricuspid valve atresia largely depend on?
-Great artery relationship
-Presence or absence of obstruction to pulmonary blood flow or systemic flow
True or False: Most patients with tricuspid atresia have normally related great arteries?
True
What % of patients with tricuspid atresia have D-TGA?
12-25%
*Aorta comes from hypoplastic RV
In tricuspid atresia, what does a large VSD in the setting of normally related great arteries result in?
Overcirculation
In tricuspid atresia, what does a restrictive VSD, pulmonary stenosis or pulmonary atresia result in?
Reduced pulmonary flow and ductal dependency
Tricuspid atresia with D-TGA and restrictive VSD result in what?
Compromised systemic blood flow- may be associated with a hypoplastic aortic arch or CoA
True or False: All patients with tricuspid atresia are committed to the single ventricle pathway?
True
-Goal to transition from parallel systemic and pulmonary circulations to circulations that are in series
What will happen to a baby with time who has tricuspid atresia with normally related great vessels, a large VSD and no evidence of obstruction to pulmonary blood flow?
Will develop excessive pulmonary blood flow as PVR drops- may be tachypneic, etc
What should be done for an infant with tricuspid atresia with normally related great vessels, a large VSD and no evidence of obstruction to pulmonary blood flow?
-Begin diuretic therapy
-Consider MPA band to protect pulmonary vascular bed from excessive pulmonary blood flow/high pressure (this makes sure the patient will be a candidate for the bidirectional Glenn then Fontan)
Why do patients need to be monitored for cyanosis after PA band in the setting of tricuspid atresia with normally related great vessels?
-Ventricular hypertrophy can develop
-This can lead to restriction of the ventricular level shunt
What needs to be done for an infant with tricuspid atresia, normally related great arteries and reduced pulmonary blood flow due to a restrictive VSD, PS or PA?
-Need a L-R shunt
-PGE to maintain ductal patency
-Eventual systemic to PA shunt or ductal stent for stable source of pulmonary blood flow
A DKS (MPA to ascending aorta) with systemic to PA shunt is needed in tricuspid atresia with what?
D-TGA and restrictive VSD
-Will have restricted systemic blood flow from subaortic obstruction from VSD and pulmonary overcirculation from increased CO from LV to MPA
-May need ductal patency to ensure adequate systemic output until surgery
Patients with tricuspid atresia and what will experience pulmonary overcirculation and will benefit from PA banding?
-Normally related great vessels
-Large VSD
What type of tricuspid atresia patients are ductal dependent pending establishment of a stable source of pulmonary blood flow?
-Normally related great arteries
-Reduced pulmonary blood flow due to restrictive VSD, PS, or PA
What type of tricuspid atresia patient will have restrictive systemic blood flow and pulmonary overcirculation?
-D-TGA
-Restrictive VSD
What is needed for tricuspid atresia patients with D-TGA and restrictive VSD?
-DKS with systemic to PA shunt (ensures adequate systemic blood flow with reduced low pressure pulmonary flow)
*Hypoplastic arch or CoA can also be addressed
When does subaortic stenosis most often occur?
In association with other forms of CHD or after prior surgical repair of CHD (rare as an isolated defect)
What are the most common congenital cardiac anomalies associated with subaortic stenosis?
-VSD
-PDA
-Bicuspid aortic valve
-CoA
-IAA (especially with co-existing Shone syndrome
-AVCD
What can be seen years following repair of a posterior malalinged VSD and IAA?
LVOTO due to subaortic membrane
What is IAA usually associated with?
-Posterior malalignment of the infundibular ventricular septum with a VSD in that region
-Aortic valve hypoplasia (bicuspid)
-AS (can be significant)
What does neonatal repair of IAA typically include?
-VSD patch closure
-Aortic arch reconstruction
What are options for neonatal repair of IAA + VSD in patients where primary VSD closure may not address the LVOTO (or LVOT stenosis or AS are significant)?
-Resection of infundibular septum with VSD enlargement
-Single or staged repair via Norwood-Rastelli approach (depending on degree of LVOT narrowing and AV morphology)
-Single ventricle palliation (severe LVOTO)
True or False: Patients with interrupted aortic arch/VSD often have residual and/or recurrent LVOTO?
True- may need to be re-addressed surgically
True or False: It would be unusual for a neonate to require isolated AV canal repair?
True (usually done at a few months of age)
True or False: Subaortic membrane is not a common post-operative complication after TAPVR?
True
What is a common complication after IAA/VSD repair?
Subaortic stenosis
What infants are considered high-risk and should be referred to a neurodevelopmental follow-up program?
-Exposure to postnatal corticosteroids
-TPN use
-In utero alcohol, nicotine or controlled substances
-High-risk cyanotic lesions
-Prolonged critical illness
-Neonatal surgery with CPB
-Prematurity
-Developmental delay
-Suspected syndrome or genetic anomaly
-Mechanical circulatory support
-Transplant
-Cardiopulmonary resuscitation
-Seizures
-Abnormal neuroimaging
*Does not specifically list high-risk medications
What are the most commonly implicated neonatal medication exposures associated with neurodevelopmental disorders?
-Neuro-sedative agents
-Antiepileptics
-Glucocorticoids
What are some of the adverse effects of loop diuretics (furosemide and bumetanide)?
-Hypokalemia
-Hypochloremia
-Metabolic alkalosis
-Hypercalciuria (leads to bone loss/renal calcification with chronic use)
-Ototoxicity
What is the ototoxic effect of loop diuretics thought to be related to?
-Peak serum concentration reaching a toxic level
*Recent study reported complete elimination of sensorineural hearing loss in patients with single ventricle disease after QI slowing the infusion rate of IV loop diuretics (lower peak serum concentration at slower rates)
True or False: Bumetanide has significantly less ototoxicity than furosemide at equivalent diuretic doses?
True- even though it has a similar MOA on the cochlea
True or False: The ototoxic effects of loop diuretics may be delayed?
True
Why is it important for patients who have required loop diuretics to have good neurodevelopmental follow-up?
-Risk for ototoxicity and sensorineural hearing loss
-Ototoxic effects may be delayed
-Many patients discharged home on diuretics
-Need comprehensive neurodevelopmental follow-up including interval language development assessments
True or False: In-utero exposure to acetaminophen has been associated with autism and ADHD?
True
*But no data linking postnatal acetaminophen with neurodevelopmental disorders
True or False: No studies have independently associated prostaglandins or ranitidine with neurodevelopmental delays?
True
What patients should be referred to a comprehensive neurodevelopmental follow-up program?
-Complex CHD
-Risk factors for neurodevelopmental disorders: Exposures to antiepileptics, neurosedatives, high-dose loop diuretics, corticosteroids
What is the position of the MPA relative to the aorta in D-TGA?
Posterior and leftward to the aorta
A large LA, elevated E/A ratio and short MV deceleration time are all indicative of what?
Abnormal diastolic function
Chronic LA HTN due to restrictive physiology can result in what?
-Arrhythmias
-Pulmonary HTN
-Thromboembolic events (stasis or pooling of blood in atria
*Could all potentially result in a syncopal episode
What happens to patients with restrictive physiology during exercise?
-Increased HR can help increase CO up to a point
-These patients have a relatively fixed SV which decreases ability to compensate for increased demands of exercise (ventricles fill less well with elevated HR)
True or False: LAE in the absence of significant MR is a relatively good marker for diastolic dysfunction in children?
True
Describe the findings on mitral valve inflow Doppler that are consistent with restrictive physiology
-Tall, narrow mitral E wave
-Diminutive A wave
-E/A ratio >3
-E wave deceleration time short (<130ms)
What causes the short E-wave deceleration time on mitral inflow Doppler in restrictive physiology?
Rapid equalization of the LA filling pressure with the elevated LVEDP in a stiff, less compliant ventricle
True or False: No single echo parameter for diastolic function should be used in isolation as a determiner for the presence of diastolic dyusfunction?
True
True or False: The application of adult echo criteria for diastolic dysfunction has overall poor correlation in pediatric patients?
True
What are the more useful parameters in children for the assessment of diastolic dysfunction?
-LA volume/size
-Short mitral deceleration times
What gives the most accurate assessment of the ventricular filling pressures and quantification of diastolic abnormalities (including restrictive physiology)?
Direct measurement of LVEDP via cath
*Also gives PA pressures and PVR which can become significantly elevated with restrictive physiology
What are some of the risks associated with cardiac cath?
-Myocardial perforation
-Arrhythmia
-TV or vessel injury
What findings would you expect on cath for a patient with a tall, narrow mitral E wave, diminutive A wave, E/A ratio >3 and E wave deceleration time <130msec on echo?
Elevated LVEDP (restrictive physiology)
Despite preserved systolic function on echo, patients after aortic valve interventions are at risk for what?
Diastolic dysfunction (restrictive physiology being on severe end of spectrum)
True or False: All patients with CHD should be educated about their diagnosis and the reasons they will need lifelong cardiology care?
True
What are some of the life-long risks for patients with CoA who have undergone surgical or catheter-based repair?
-Recurrent CoA
-Aortic aneurysms
-Pseudoaneurysms
-Aortic dissection
-HTN
What % of patients with repaired CoA require reintervention in adulthood?
11%
What kind of imaging should all adults with repaired CoA have periodically?
3D imaging of the aorta via MRA or CTA
What are some of the Class I recommendations for adults with repaired CoA?
-3D imaging of aorta via MRA or CTA periodically
-Checking resting BP in upper/lower extremities to assess for recoarctation
-Surgical repair or catheter-based stenting in patients with recoarctation and HTN
-Goal-directed medical therapy for the management of HTN
When treating an adult s/p CoA repair for HTN, what do you have to be cautious about?
That degree of CoA isn’t so severe to acutely decrease LE perfusion with aggressive anti-hypertensives until recurrent CoA is managed appropriately
What are the Class II recommendations for adults with repaired CoA?
-Ambulatory BP monitoring to diagnose/manage HTN
-Screening for intracranial aneurysms
-Exercise testing to assess for exercise-induced HTN
-Balloon angioplasty in patients with CoA who are ineligible for stent placement or surgical repair
Intracranial aneurysms can occur in up to what % of patients with CoA?
10%- and can increase in frequency with age
True or False: In adults s/p CoA repair, TEE may be able to identify an area of recurrent CoA, but can’t profile the entire thoracic aorta and may be insufficient for identifying aneurysms, pseudoaneurysms, dissections or remotely located CoA?
True- why cross-sectional imaging is more appropriate (especially with incomplete history or gaps in follow-up)
What is the most common genetically inherited hyperlipidemia?
Familial hypercholesterolemia
Which is more common, heterozygous or homozygous familial hypercholesterolemia?
Heterozygous
-Heterozygous: 1/200-250
-Homozygous: 1/160,000-300,000
When should children be screened for hyperlipidemia regardless of risk factors or comorbidities?
9-11 and 17-21
Which children should have hyperlipidemia screening starting after age 2?
-CV Risk Factors: CHD, Kawasaki disease with persistent coronary artery aneurysms, heart transplants
-Non-CV Risk Factors: Chronic renal disease, DM, stem cell transplants
Familial hypercholesterolemia should be suspected in any pediatric patient with what findings?
-Fasting LDL >160mg/dL
-Family history of premature CAD or elevated LDL in a 1st degree relative
If an LDL level > what is detected in a patient <20 years, there is an 80% chance of familial hypercholesterolemia?
190
Mutations in what genes can be detected by genetic testing for familial hyperlipidemia?
-LDL receptor
-Apolipoprotein B
-Proprotein convertase subtilisin/kesin type 9 (PCSK9)
*Genetic testing isn’t routinely recommended
What are the first line of pharmacologic agents to treat familial hypercholesterolemia in children and adults?
Statins
How do statins work?
-Inhibition of the 3-hydroxy-3-methylglutaryl coenzyme A reductase (rate-limiting enzyme in cholesterol biosynthesis)
-Upregulates LDL receptors in the liver
Besides lowering LDL, what other effects do statins have?
-Modest effect on lowering triglyceride levels
-Modest effect on raising high-density lipoprotein cholesterol levels
What does the expected effect on LDL lowering with statin use depend on?
Dose and intensity of the statin
What are considered to be the more potent statins?
-Atorvastatin
-Rosuvastatin
Which 2 statins are approved for use in children as young as 8?
-Pitavastatin
-Pravastatin
Which statins are approved for use in children over 10?
-Atorvastatin
-Rosuvastatin
-Lovastatin
-Fluvastatin
*In addition to pitavastatin and pravastatin
How are statins started/titrated in children?
-Start with lowest possible dose
-Gradual up-titration to achieve desired LDL <130
What are some of the adverse effects of statins?
-Statin-associated muscle symptoms
-Increase in hepatic transaminases
-Transient GI upset
-Concern for teratogenicity
True or False: Multiple studies have found no adverse effects of statins on growth, development or sexual maturation?
True
What are clinically significant adverse effects of statins that require discontinuation of therapy?
-Severe myopathy
-Rhabdomyolysis
-Hepatic dysfunction
*Rare in children and adolescents
How often should LFTs be checked when starting a statin?
-Before initiation
-Repeat measurements at 4, 8 and 12 weeks after initiation
An elevation in hepatic transaminases above what is concerning and should prompt discontinuation of statin therapy?
> 3x upper limit of normal
*Should evaluate for alternative causes for the increase as well
True or False: If you stop a statin for elevated transaminases, you can re-initiate treatment with a statin at a lower dose (or different statin) with close monitoring of transamianses once the levels have normalized?
True
Besides LFTs, what other lab value should be measures before initiating a statin?
Creatinine kinase (CK)
When do repeat CK levels need to be checked when starting a statin?
Only if the patient has muscle symptoms
A CK level above what should prompt temporary discontinuation of a statin?
CK >10x the upper limit of normal
*or clinically significant statin-associated muscle symptoms- be sure to assess for alternative etiologies (exercise, hypothyroidism, trauma)
True or False: You can try to reinitiate statin therapy after it was discontinued due to elevated CK/muscle symptoms?
True- once levels/symptoms have normalized… re-start in controlled fashion at a lower dose
What do you need to counsel female patients about who are taking a statin?
Teratogenic effects of the drug
What can be given to patients with clinically significant elevations in TG levels to prevent acute episodes of pancreatitis?
Fenofibrate or bezafibrate (minimal effect on LDL)
What is a cholesterol absorption inhibitor that is used as an adjunct with statin for lowering LDL to reach the optimal levels?
Ezetimibe
What can be used as monotherapy for LDL control in patients with adverse effects to statins?
Ezetimibe (but this is rare)
How much does ezetimibe lower LDL?
By 15-20%
What age and what dose can you use ezetimibe?
> 10 years, 10mg/day
What supplements can be used to lower LDL levels up to 15%?
Phytosterol
What is the dose of phytoserol?
2g/day
When is phytosterol supplement no effective?
When a reduction LDL >50% or up to <130mg/dL is desired
*This is what’s needed in patients with familial hypercholesterolemia and why statins are used
What is the most common genetically inherited hyperlipidemia?
Familial hyoercholesterolemia
What is the most common hertiable chest wall abnormality?
Pectus excavatum
What is pectus excavatum?
Congenital anterior chest wall deformity in which the sternum and rib cage are shaped abnormally, leading to a funnel-shaped or caved-in appearance of the chest
When does pectus excavatum become most noticeable?
During adolescent growth spurts (but can be present from birth)
Pectus abnormalities are more common in which gender?
Males (by a factor of at least 2:1)
What testing is usually done as part of the evaluation for possible pectus?
TTE
Severe cases of pectus excavatum have been associated with what cardiac findings?
-RV distortion
-RV compression
-Impaired RV filling
*These are considered a rationale for surgical repair beyond cosmetic reasons
Pectus excavatum and carinatum are associated with what other findings?
Marfan syndrome and other connective tissue abnormalities (Loeys-Dietz and Ehlers-Danlos)
Isolated pectus excavatum is associated with an increased risk for what?
MVP- reported in 18-45% of patients with isolated pectus abnormalities
Besides MVP, what other finding is more common in patients with pectus excavatum than the general population?
Aortic root dilation
Patients who have a combination of pectus excavatum (or carinatum), MVP and aortic dilation should undergo a thorough investigation for what?
Other connective tissue abnormalities (even if other physical stigmata of a connective tissue disorder aren’t obvious)
True or False: Many genetic abnormalities can be associated with pectus chest wall abnormalities and cardiac abnormalities (like Noonan and Turner)?
True
True or False: Isolated pectus excavatum has been assocaited with abnormalities of teh RV including RV awll motion abnormalities due to compression or distortion, pulmonary hypertension and RV dysfunction?
False
*Yes to RV wall motion abnormalities due to compression or distortion
*No to pulmonary HTN or RV dysfunction
What is the most common surgical technique for repair of isolated pectus excavatum abnormality?
Nuss procedure
How is the Nuss procedure for repair of isolated pectus excavatum abnormality performed?
-Minimally invasive surgical thorascopy technique
-Position a bar (Lorenz or Nuss bar) below the sternum
-Then it is inverted to raise and reposition the sternum and ribcage
What is warranted before possible surgical intervention for pectus excavatum?
Cardiology clearance to assess for evidence of cardiac distortion or compression (RV) in addition to MVP, aortic dilation or other forms of CHD that may distort or complicate the surgical intervention
How long does a Nuss bar remain in place following repair of isolated pectus excavatum abnormality?
2-3 years, then removed
True or False: After the Nuss procedure, improvement in cardiopulmonary performance has been reported in patients with pectus excavatum?
True
Patients with pectus excavatum who are also found to have MVP, aortic root dilation or both should undergo what?
Genetic screening for possible associated connective tissue disorders such as Marfan
What is cor triatriatum sinister?
-Congenital cardiac lesion in which the LA is divided into 2 chambers by a fibromuscular diaphragm
-Diaphragm can result in obstruction of the pulmonary venous return depending on the presence and number of fenestrations in the diaphragm
-Rare- 0.4% of patients with CHD
What are the most commonly associated lesions with cor triatriatum sinister?
-ASD
-Anomalous pulmonary venous connection
When do symptoms with cor triatriatum sinister develop?
Usually infancy, but has been reported to be incidentally found in adulthood
What are the symptoms of cor triatriatum sinister?
-Similar to MS
-Dyspnea, poor weight gain, poor feeding
When is surgery indicated for cor triatriatum sinister?
When there is obstruction at the membrane
-Also repair any associated lesions
True or False: Surgery for cor triatriatum sinister is considered safe, with a very low risk of recurrent obstruction?
True
What is it called when there is cor triatriatum in the right atrium?
Cor triatriatum dexter
What is caused by a fibromuscular diaphragm that separates the LA into 2 chambers?
Cor triatriatum sinister
What are symptoms in cor triatriatum sinister related to?
Presence and degree of obstruction at fenestrations in the diaphragm
What are symptoms of cor triatriatum sinister similar to?
MS- Tachypnea, poor growth, poor feeding
How do you identify the location of an accessory pathway?
Find the earliest atrial activation during tachycardia
For an EP study, the distal CS (CS1) is located where?
Most leftward (v. proximal CS (CS9) which is closer to the atrial septum)
In patients with a right lateral accessory pathway, where would you expect the earliest atrial activation to be?
Around the high right atrium catheter
For a patient with SVT using a septal accessory pathway, the earliest retrograde atrial activation would be where?
Around CS9 (proximal CS) or close to the His catheter
Describe the circuit for SVT with an accessory pathway?
-Antegrade via AV node
-Retrograde via AP
Describe the circuit for SVT with typical AVNRT
-Down the slow
-Up the fast
For an accessory pathway, the tachycardia has what pattern of activation?
His-Ventricle-Atria
For AVNRT, the tachycardia usually has what pattern of activation?
His-Atria-Ventricle… see simultaneous activation of A and V
*Can be H-V-A
For AVNRT with a His-Ventricle-Atrial pattern, where would the earliest atrial activation be?
Along the septum- His and CS9 (proximal CS)
Accessory pathway-mediated SVT will have what pattern of activation?
H-V-A
The earliest site of atrial activation during accessory pathway-mediated tachycardia will be where?
At the site where the AP is located
A patient with D-TGA s/p atrial switch is at high risk for what type of arrhythmias?
Atrial arrhythmias (fibrillation, flutter, etc)
Patients with recurrent or chronic atrial fibrillation/flutter require what?
Anticoagulation for thomrboprophylaxis
How does an anti-factor Xa level work?
-Functional assay
-Mix patients blood with known amount of active factor Xa
-Depending on the level of active factor Xa after blood has been mixed (based on established nomograms), the level (and effect) of anti-factor Xa can be calculated
An anti-factor Xa level can be used to monitor what?
Levels of heparin, LMWH, and direct factor Xa inhibitors (like rivaroxaban)
What type of drug is rivaroxaban?
Direct factor Xa inhibitor
What type of functional assay is a heparin test?
One that detects the anti-factor Xa level
Results of a heparin test (functional assay that detects the anti-factor Xa level) will be positive for patients taking what?
Novel oral anticoagulants (NOACs)
What are the 2 classes of anticoagulants commonly used in ambulatory settings?
-Vitamin K antagonists (warfarin)
-Factor Xa inhibitors (LMWH and direct factor Xa inhibitors like edoxaban, rivaroxaban, apixaban)
How are vitamin K antagonists administered?
Warfarin- PO
True or False: Vitamin K antagonists need frequent lab monitoring and have a narrow therapeutic range?
True- Warfarin
How is LMWH given?
Injection BID
*Needs lab monitoring to maintain a safe range
How is LMWH eliminated?
Renal- will need renal adjustment of dosing if creatine clearance decreases below 30mL/min
What are some of the benefits of direct factor Xa inhibitors?
-Novel oral anticoagulants or direct-acting oral anticoagulants)
-PO administration
-Less frequent lab monitoring
-Used in patients with creatinine clearance as low was 15-30mL/min without adjustment
How are the direct factor Xa inhibitors cleared?
Renally- they can build up in the setting of an acute kidney injury
What is an antiplatelet agent (platelet inhibitor) that may be used for thromboprophylaxis in patients with heart failure?
ASA
True or False: At antiplatelet dosing, ASA is unlikely to cause AKI?
True
Acetaminophen toxicity causes what?
Elevated transaminase levels
How is enoxaparin given?
Injections
What is a direct thrombin inhibitor used in patients with contraindications to heparin (like HIT)?
Dabigatran
True or False: Dabigatran causes elevated anti-factor Xa levels on lab testing?
False
What are 2 novel oral anticoagulants that are direct factor Xa inhibitors?
Apixaban
Rivaroxaban
True or False: The novel oral anticoagulants apixaban and rivaroxaban have a wide therapeutic window and don’t need frequent dose titration?
True
True or False: The novel oral anticoagulants apixaban and rivaroxaban will have a positive result on a heparin test or an anti-factor Xa test?
True
True or False: ASA has no impact on heparin or anti-factor Xa test results?
True
What should be done immediately for a patient s/p cavopulmonary anastomosis with significant hypoxia?
-CXR: Rule out any intrathoracic process like hemo/pneumothoraces, significant atelectasis, enlarging cardiomediastinal silhouette, or pulmonary edema
-TTE: Often limited in assessing for obstruction in the cavopulmonary pathway or branch PAs, or baffle leak (for Hemi-Fontans), but should be attempted
*If no cause found, do these things while arranging for cath
For a post-operative cavopulmonary anastomosis with significant hypoxemia, what needs to be diagnosed and how once any intrathoracic or pulmonary processes are ruled out with CXR?
Cath- Need to assess for any post-operative complications like an obstruction in the cavopulmonary circuit or baffle leak
*May need the surgeon to re-explore the patient surgically without further diagnostic testing
True or False: The use of a transjugular Swan-Ganz catheter is not often used in PICU because of the risk of pulmonary artery perforation?
True- Also less likely to be diagnostic without bedside fluoroscopy and angiography
Hypoxic patients who have undergone the bidirectional Glenn procedure or cavopulmonary anastomosis require evaluation for what?
-Intrathoracic processes
-Pulmonary dysfunction
-Cardiac dysfunction
-Interrogation of the cavopulmonary circuit- Obstruction or baffle leaks
Patients with ToF and moderate to severe _ deviation of the subpulmonary infundibulum can be prone to dynamic subpulmonary narrowing and worsening RVOTO
Anterior and superior
What causes a hypercyanotic (“tet”) spell?
Abrupt change in ratio of pulmonary to systemic blood flow
What can precipitate a hypercyanotic spell?
Dehydration
Agitation
The degree of cyanosis in ToF is dictated by what?
-Severity of fixed and dynamic PS
-Ratio of SVR to PVR
*Increased subpulmonary stenosis and increased PVR promote more desaturated blood to shunt R-L across the VSD and out the aorta
The mechanism of a hypercyanotic spell in ToF patients is often secondary to what?
-Changes in RV contractility
-Endogenous catecholamines
-Hypovolemia
Describe the cycle of a hypercyanotic spell
-Changes in RV contractility, endogenous catecholamines, hypovolemia
-Severe dynamic subpulmonary obstruction
-Increased R-L shunting across the VSD
-Leads to hypoxia and increases PVR
-Leads to a vicious cycle of worsening hypoxia and increased R-L shunting of desaturated blood across the VSD
Why is there diminished murmur intensity in a hypercyanotic spell?
Dynamic subpulmonary stenosis leads to decreased blood flow across the RVOT… this results in diminished murmur intensity
What are things that can aggravate a hypercyanotic spell?
-Hyperpnea (often a response to acute hypoxia and secondary metabolic acidosis)
-Crying
-Agitation
-Exertion
True or False: Hypercyanotic spells may lead to hypoxia, syncope, seizures and even death?
True
What are the clinical treatments for a hypercyanotic spell directed at?
Increasing the amount of pulmonary blood flow by increasing SVR and decreasing resistance to pulmonary blood flow
What are some options for management of a hypercyanotic spell?
-Knees to chest (compresses femoral vessels and increases SVR)
-Fluid resuscitation (increases preload)
-O2 (decreases PVR and increases O2 content)
-Phenylephrine (increases SVR)
-Sedation (reduces O2 demands)
-IV B-blocker (slow HR to decrease dynamic subpulmonary obstruction by promoting ventricular diastolic filling)
*If refractory to medical therapies, may need ECMO or emergent sugery
What is the risk of a hypercyanotic spell in ToF largely determined by?
Degree of anterosuperior deviation of the subpulmonary infundibulum causing subpulmonary narrowing
What is treatment of a hypercyanotic spell directed at?
Increasing the amount of pulmonary blood flow by increasing SVR, reducing dynamic obstruction and decreasing PVR
Antracycline doses above what put patients in a high-risk category for cardiotoxicity?
250mg/M2- although any exposure can cause myocardial injury
Radiation exposure at levels above what places a patient at risk for developing cardiovascular side effects?
35Gy
What is one of the side effects associated with radiation exposure?
Constrictive pericarditis
What findings can be seen on ECG in constrictive pericarditis?
Low-voltage QRS
What are some findings on echo that are consistent with constrictive pericarditis?
-Bright pericardial border
-No significant pericardial effusion
-Normal systolic biventricular function
-Abnormal ventricular septal bounce
-Elevated mitral e’ on TDI
-Mitral valve inflow variation with respiration
-Hepatic vein a-wave reversal with respiration
What findings on cath are consistent with constrictive pericarditis?
-Equalization of pressures in the cardiac chambers
-Square-root sign appearance of the diastolic pressure tracings
What is seen on CMR or CT in constrictive pericarditis?
Thickening of the pericardium
What is a concern giving lasix to someone with constrictive pericarditis?
-Potential to volume deplete the patient
-Reduces preload
-Can result in circulatory collapse
If PE findings are consistent with pericardial effusion in an oncology patient, but there is no pericardial effusion on echo, what diagnosis should you consider?
Constrictive pericarditis (especially if they received radiation)
Why should fluids be given cautiously to someone with constrictive epricarditis?
-May make them symptomatic (tachypneic, etc)
-Equal/elevated end diastolic and atrial pressures, can’t handle more volume above a certain point
What is definitive treatment for constrictive pericarditis?
Pericardiectomy or “pericardial stripping”
-Removal of the thickened, fibrotic layer that develops after radiation exposure can be a definitive therapy to normalize the elevated end diastolic ventricular pressures and constrictive physiology
What can happen to the pericardium after radiation therapy?
It can become thickened and fibrotic
What is the pericardium?
Double-layer sac that provides lubrication for the heart
True or False: Pericardiectomy doesn’t always eliminate symptoms of constrictive pericarditis due to the difficulty completely removing an adherent pericardium
True
Radiation therapy can lead to what?
Constrictive pericarditis
*May manifest similarly to other sequelae of treatments for pediatric cancers
What do you need to be cautious about in someone with constrictive pericarditis?
Fluid management… need to be cautious with fluids and diuretics
What is the definitive therapy for constrictive pericarditis?
Pericardiectomy
*Symptom relief is variable
What are other names for left posterior fascicular (LPF) ventricular tachycardia?
-Verapamil sensitive VT
-Belhassen VT
Describe verapamil sensitive VT
-RBBB pattern (rsR’)
-LAD
-Discrete Q waves in I and aVL
What is the most common type of VT originating from the LV in young patients with a structurally normal heart?
Verapamil sensitive VT
Describe patients who develop verapamil sensitive VT?
-Young and healthy
-Often experience first episode during adolescence
What can precipitate episodes of verapamil sensitive VT?
-Exercise
-Excitement
-Infection
What are typical presenting symptoms of verapamil sensitive VT?
Palpitations
Dizziness
Fatigue
Shortness of breath
True or False: Verapamil sensitive VT episodes are usually well tolerated and the patients are often hemodynamically stable?
True
What medication is effective for left posterior fascicular ventricular tachycardia or Belhassen tachycardia?
Verapamil- why called verapamil sensitive VT
What is the typical ventricular rate in verapamil sensitive ventricular tachycardia?
150-220bpm
What is verapamil sensitive ventricular tachycardia often misdiagnosed as?
SVT with aberrancy
True or False: The incidence of syncope and sudden death is rare in verapamil sensitive ventricular tachycardia?
True
For patients with verapamil sensitive ventricular tachycardia who have frequent episodes or are averse to long-term medical therapy, what is a good option?
Catheter ablation
What is the mechanism for verapamil sensitive ventricular tachycardia?
-Re-entry involving the left posterior fascicle, abnormal Purkinje system and part of the adjoining myocardium in the LV with slow/decremental conduction properties
-The abnormal Purkinje system is verapamil sensitive
Where is ablation needed for verapamil sensitive ventricular tachycardia?
Apical third of LV septum
True or False: Left posterior fascicular ventricular tachycardia generally doesn’t respond to adenosine?
True (rare case reports of rate responsiveness to adenosine)
Describe the QRS morphology in RVOT VT?
LBBB with inferior axis
A rate around what is commonly seen in atrial flutter with 2:1 conduction?
150bpm
If there is VA dissociation during a tachycardia, which 2 diagnoses are unlikely?
SVT
Atrial flutter
What are 2 medications which can be used to help with atrial flutter?
-Beta-blocker for rate control
-Ibutilide for chemical cardioversion
What is the most common type of VT originating in the LV in young patients with structurally normal hearts?
Left posterior fascicular ventricular tachycardia
Belhassen VT
What are the ECG findings consistent with left posterior fascicular ventricular tachycardia?
Wide-complex tachycardia with a RBBB morphology and superior axis
Left posterior fascicular ventricular tachycardia is very responsive to what?
Verapamil
For SVT, if the atrial activation occurs in the 1st half of the RR interval, it is defined as what?
Short RP tachycardia
What represents the most distal electrode on a CS catheter?
CS1
Where is CS1 located for an EP study?
Close to the left lateral MV annulus in the LAO fluoroscopic view
The LAO view shows what view of the AV valves?
En face
CS1 and CS2 during an EP study will be closest to what?
Left lateral MV annulus (4 o’clock position on MV annulus)
If there is earliest atrial activation at CS1 during SVT, where is the pathway?
Left lateral AP
Describe the circuit in a left lateral accessory pathway mediated tachycardia
-Antegrade conduction over the AV node (results in a narrow QRS complex)
-Eccentric retrograde conduction over the left lateral accessory pathway (results in earliest atrial depolarization on CS1/CS2 electrode pair what is closest to the AP)
If you have a left lateral accessory pathway, what is required for mapping and ablation?
A transseptal puncture to access the LA
*In the past, used to use a retrograde approach from the femoral artery, but now most EP use transseptal approach
The risk of AV block during an AP ablation is increased if the ablation target is where?
-Anteroseptal/parahisian
-Midseptal
Why are right-sided APs on the lateral tricuspid valve annulus more likely to recur?
Stability of the ablation catheter is difficult to achieve
What is the recurrence risk of left lateral accessory pathways?
<5%
Occasionally, APs in the epicardial posteroseptal and left posterior locations are associated with what?
Presence of a diverticulum of the CS
If there is a diverticulum of the coronary sinus, where is it located?
Between the origin of the middle and posterior cardiac vein
With an AP in the epicardial posteroseptal or left posterior location associated with a diverticulum of the CS, what may be needed to assess for the approximation to the coronary arteries to the potential ablation site in the CS diverticulum?
CS venogram and coronary artery angiogram
*Given proximity of the coronary artery in this location, the EP may use cryoablation for these APs
True or False: With a left lateral AP, a venogram is required prior to ablation because of the risk of damage to a coronary artery?
False- Left lateral MV annulus isn’t the typical location of the CS diverticulum (situation where you may need a venogram due to risk for proximity to and injury of the coronary arteries… these are the APs in the epicardial posteroseptal and left posterior locations)
What is the ablation target in accessory pathway mediated orthodromic SVT?
Earliest site of retrograde atrial activation
If atrial activation falls in the first half of the RR interval, it is defined as what type of tachycardia?
Short RP
What should be included in the differential diagnosis for a patient with HF symptoms and a severely enlarged cardiac silhouette on CXR in infancy?
-ALCAPA
-Critical CoA
-Critical AS
-Myocarditis
-Tachycardia induced cardiomyopathy
-Idiopathic DCM
-Metabolic abnormalities (Pompe)
Deep Q waves in I and aVL?
ALCAPA
Describe the pathophysiology of ALCAPA
-Based on anomalous origin of the coronary artery and normal drop in PVR over time
-Initially, the LV myocardium is perfused with PA blood (lower O2 content), but relative normal perfusion pressure due to elevated PVR after birth
-As PVR falls, perfusion pressure diminishes causing ischemia to LV and consequent deep Q waves in I and aVL
-Eventually can result in reversal of flow into the PA via collateral arteries between the right and left coronary systems
-Ischemic environment can lead to LV systolic dysfunction, infarction of the papillary muscles, significant MR and death
How do the coronary arteries develop embryologically?
-Do not arise from the aortic root and grow out
-Form through a process of coalescence of endothelial progenitor cells and then grow into the aortic wall (likely through the guidance of vascular endothelial growth factor and periaortic cardiomyocytes)
What is the incidence of ALCAPA?
Low- 1/300,000
When does ALCAPA present?
Bimodal- 90% in infancy, 10% in childhood or adulthood
What leads to a later presentation of ALCAPA?
Extensive collateralization between the right and left coronary systems (may limit ischemia and heart failure)
*Adolescent patients may experience sudden cardiac arrest
How should ACLAPA be imaged on echo?
2D and Color Doppler in PSSA/PSLA and subcostal short axis
*Imaging without color may lead to a missed ALCAPA diagnosis because the left coronary artery may be very close to the left coronary cusp
What can be seen on echo in an infant with ALCAPA after the PVR has decreased?
Flow from the coronary artery into the PA
Besides the actual coronary, what are other clues on echo to a diagnosis of ALCAPA?
-Echobright papillary muscles
-Significant MR
What is required if echo can’t confirm a diagnosis of ALCAPA?
-Cath
-CTA
What should be considered in an infant with heart failure symptoms and ECG with deep Q waves in I and aVL?
ALCAPA
How do the coronary arteries form?
-Process of coalescence of endothelial progentior cells
-Grow into the aortic wall
Echo imaging of the left coronary artery without color Doppler may lead to a missed diagnosis of what?
ALCAPA
What is a lysosomal transport disorder classified as a glycogen storage disease (type IIb) without the metabolic components classically associated with glycogen storage diseases?
Danon disease
What causes Danon disease?
Mutation in the lysosomal-associated membrane protein-2 (LAMP-2)
*Impairs the process of transporting cellular material into the lysosome
Which gender is more significantly affected by Danon disease?
Males (childhood or adolesnce) and more severely than females
Describe the cardiac findings seen in Danon disease?
-Cardiomyopathy (most often HCM, but DCM has bee described)
-WPW/pre-excitation
-Pseudo-preexcitation
-Risk for arrhythmia
Describe the non-cardiac findings seen in Danon disease?
-Proximal skeletal myoathy: Upper arms, shoulders, neck, upper thighs
-Possible elevated creatine kinase levels
-Most (but not all) male patients have mild intellectual disability (can be overlooked)
Describe the presentation of Danon disease in a female?
-Affected in early adulthood
-Develop cardiomyopathy (50% HCM, 50% DCM)
-Less likely to have skeletal myopathy or intellectual disabilities
True or False: Children with Danon disease can get a heart transplant?
True
*Some case reports suggest that steroids may exacerbate skeletal myopathy
What is a progressive X-linked lysosomal disorder of glycosphingolipid metabolism as a result a deficient or absent lysosomal a-galactosidase A activity?
Fabry disease
What is another name for Fabry disease?
Anderson-Fabry disease
What are some of the symptoms in childhood associated with Fabry disease?
-Pain: Episodic crises with agonizing, burning pain that originates in the extremities and radiates inwards and chronic pain with burning or tingling paresthesia triggered by or accompanied by fever
-GI symptoms
-Anhidrosis/hypohidrosis
-Skin lesions
-Eye exam findings
-Kidney involvement
-Cardiac disease
What are the cardiac manifestations of Fabry disease?
-Presents in adolescence
-LVH
-Shortened PR interval
-Arrhythmias
-Valvular insufficiency
*With age, progressive myocardial fibrosis that leads to systolic dysfunction and malignant arrhythmias
Which gender manifests symptoms earlier and in a more severe form with Fabry dsiease?
Males (as compared to female heterozygotes)
True or False: There is a cardiac variant of Fabry disease without overt systemic involvement that has been shown to account for up to 4% of cases of HCM?
True
What can be done to halt disease progression in Fabry disease?
Enzyme replacement therapy
True or False: Fabry disease is associated with intellectual disabilities?
True
What is an AR disorder that prevents the body from converting certain fats to energy during periods of stress?
Long-chain L-3 hydroxyacyl-CoA dehydrogenase deficiency (LCHAD)
What mutation causes LCHAD?
HADHA gene- Affects production of an enzyme complex (mitochondrial trifunctional protein)
What are the signs and symptoms of LCHAD?
-Appear during infancy or early childhood
-Feeding difficulties
-Lethargy
-Hypoglycemia
-Hypotonia
-Liver problems
-Eye problems
-Cardiomyopathy
What is important in the management of LCHAD?
Early recognition… dietary change can be beneficial
True or False: LCHAD would be in the differential of a late-onset cardiomyopathy?
False
What is a glycogen storage disease with abnormal production and function of the acid alpha-glucosidase enzyme?
Pompe disease
A mutation in what causes Pompe?
GAA gene
What are the 3 forms of Pompe?
-Classic infantile onset
-Non-classic infantile onset
-Late-onset
Describe classic infantile onset Pompe
-Begins within first 3 months of life
-Muscle weakness
-Hypotonia
-Hepatomegaly
-HCM
Describe the non-classic infantile onset Pompe?
-Appears by age 1
-Delayed motor skills
-Progressive muscle weakness
-May have HCM, but less likely to present with heart failure
Describe late-onset Pompe
-May present in adolescence or adulthood with progressive muscle weakness in legs and trunk
-May have CV abnormalities on baseline ECG or Echo (including pre-excitation), but unlikely to have significant hypertrophy as classically seen in infantile Pompe
What is a lysosomal transport disorder secondary to a mutation in the LAMP2 gene that causes HCM in young males and HCM/DCM in adult females?
Danon
Danon, Fabry and Pompe disease can have what findings on ECG?
-Pre-excitation or WPW
-LVH
-Short PR interval
True or False: Late-onset cardiomyopathy can be associated with metabolic disorders?
True
*Metabolic diseases are in the differential for infantile cardiomyopathies
What is one of the more rare causes of myocarditis?
Giant cell myocarditis
True or False: Giant cell myocarditis is only seen in adults?
False- can be seen in children and adults
True or False: Giant cell myocarditis can be refractory to treatment in many cases?
True
What problem is giant cell myocarditis associated with?
Development of complete heart block (5%)
What is seen on histology for giant cell myocarditis?
-Mixed infiltrate of mononuclear cells, eosinophils, histiocytes, and multinucleated giant cells with extensive myocyte necrosis
In terms of function and dilation, what is seen in fulminant myocarditis?
Depressed biventricular function without ventricular dilation (indicative of an acute process)
True or False: Patients with giant cell myocarditis often have acute fulminant myocarditis and may need intensive care, including PPV?
True
There is an association between giant cell myocarditis and what?
Immune disorders
Giant cell myocarditis is in a group of causes of myocarditis that response to what?
Immunosuppression (especially steroid-based regimens)
True or False: Patients who go on to develop chronic heart failure symptoms after myocarditis may need to be listed for heart transplant?
True
True or False: Treating a patients with immunomodulatory and immunosuppressive therapies may treat the inflammatory process and help with myocardial recovery in giant cell myocarditis?
True- try this before listing for transplant
Why are transplant outcomes for patients with giant cell myocarditis less favorable than for those with other forms of cardiomyopathy?
-Giant cell infiltration of the donor heart has been reported
*Heart transplant is still a potential therapeutic option
Compared with viral myocarditis, there is a wider consensus to use what in giant cell myocarditis?
Combination immunomodulatory therapeutics
What has been shown to ameliorate the effects of giant cell myocarditis such that it can potentially go into clinical remission and allow for recovery from heart failure in approximately 2/3 of those affected?
Corticosteroids + Immunosuppressants (cyclosporine or azathioprine)
What medication is used in recurrent or refractory cases of giant cell myocarditis?
Rituximab- not a first-line agent for the treatment of myocarditis (GCM or any other type)
What is rituximab?
Monoclonal antibody therapy directed to the CD20 antigens on B-cells
*Used in recurrent or refractory cases of giant cell myocarditis
What is anakinra?
IL-1 receptor antagonist
When is anakinra used in myocarditis?
For atypical or refractory cases- not considered 1st line therapy
True or False: Giant cell myocarditis represents a rare etiology for myocarditis and one that is associated with a poor prgonsis?
True
What is often used as 1st line therapy for giant cell myocarditis?
Immunomodulatory and immunosuppressive agents (differentiates from more routine viral myocarditis
What are some of the etiologies of myocarditis?
-Viral
-Inflammatory
-Toxin
-Drug
Describe an outflow tract PVC
-PVC axis positive in inferior leads (focus from more superior portion of heart- outflow)
-LBBB morphology with transition at V3-V4 (suggests coming from RVOT)
What does a transition earlier than V3-V4 suggest as origin of a PVC with LBBB morphology?
Coronary cusps
True or False: PVCs can be frequently encountered in pediatric patients and tend to have a good overall prognosis in asymptomatic patients who have uniform PVCs and a structurally normal heart with no concerning family history?
True
True or False: It is unlikely for patients with uniform PVCs and no cardiac abnormalities to have worsening of their clinical status over time?
True
What is usually required in patients with PVCs?
Observation
A PVC burden over what % on a 24 hour Holter monitor increases the risk of developing ventricular dysfunction and warrants longitudinal observation?
10-20%
What needs to be considered as an underlying diagnosis in a patients with PVCs that arise from the RVOT?
ARVC- PVCs could be an early manifestation
If a patient is having >500 ectopic beats in a 24 hour period that are RVOT in origin and a concerning personal/family history or echo findings suggestive of ARVC, what should be considered?
CMR
Medical or catheter treatments in patients with frequent PVCs is usually reserved for who?
-Symptomatic
-Ventricular dysfunction
-Hemodynamically significant ventricular arrhythmias
What are the most common used first line medications for PVCs that warrant treatment?
-B-blockers
-CCB (if >1 year)
True or False: Outflow tract PVCs overall tend to have a benign course?
True
What is considered mild-moderate hypertriglyceridemia?
150-500
What are some things that can cause mild-moderate hypertriglyceridemia?
-Obesity
-Type 2DM
-Thyroid dysfunction
-Renal or hepatic disease
-Drugs: PO retinoids, thiazides, B-blockers, estrogens, glucocorticoids, HIV medications (protease inhibitors), antipsychotics
-Alcohol
True or False: Lifestyle changes will often normalize triglyceride levels in most patients with mild-moderate elevation?
True
What is considered severe elevation in triglyceride levels?
> 1000
Severe elevations in TG over 1000 is a clue to what?
Underlying monogenic or polygenic inheritance
A small subset of patients with severe hypertriglyceridemia have what?
Familial chylomicronemia syndrome
What is the breakdown of inheritance types in familial chylomicronemia syndrome?
80% AR
20% genetic defects in APOC2, APOA5, LMF1, GP1HBP1
What causes AR familial chylomicronemia?
Genetically mediated deficiency of lipoprotein lipase (LPL) enzyme resulting in poor catabolism of triglyceride-rick lipoproteins such as chylomicrons
Genetic defects in APOC2, APOA5, LMF1, GP1HBP1 cause what?
Familial chylomirconemia syndrome- these genes encode cofactors or binding proteins required for efficient functioning of the LPL enzyme
How do patients with familial chylomicronemia syndrome present?
Childhood or adolescence with recurrent bouts of acute pancreatitis secondary to clogging of the pancreatic capillaries with TG-rich plasma
What is seen on physical exam in familial chylomirconemia?
-TG-laden yellowish papules on the extremities, torso and back (eruptive xanthomas)
-Lipemia retinalis
-Hepatosplenomegaly
What is the hallmark of familial chylomicronemia?
Milky/turbid plasma due to excess chylomicrons
What is seen on lipid profile in familial chylomicronemia?
-Serum triglyceride levels are markedly elevated
-Normal to subnormal levels of remaining lipoproteins
How is familial chylomicronemia diagnosed?
-Clinical history
-Lipid profile (elevated TG levels, normal to subnormal levels of remaining lipoproteins)
*Genetic testing can be done for a definitive diagnosis, but isn’t widely available
What is the treatment for familial chylomicronemia?
-Restricting fat intake to <10-15% caloric intake (15-20g/day)
-Avoid alcohol
-Limit simple, refined carbohydrates
*Despite strict adherence, patients will have breakthrough episodes of pancreatitis
In familial chylomicronemia, what is needed in terms of dietary considerations?
-Restricting fat intake to <10-15% caloric intake (15-20g/day)
-Avoid alcohol
-Limit simple, refined carbohydrates
-Work with RD/nutritionist
-Monitor levels of fat-soluble vitamins
-Consider MCT oil (metabolized via a chylomicron independent pathway)
What is used in mild-moderate hypertriglyceridemia, but is unlikely to be beneficial in patients with familial chylomicronemia?
Fibrates and omega-3 fatty acids
What is Volanesorsen?
Antisense oligonucleotide inhibitor (ASO) of apo C3 which reduces rates of pancreatitis and TG levels in familial chylomicronemia
*Conditionally approved in Europe
*Limited by high cost
True or False: There are currently no medications approved by the FDA to treat familial chylomicronemia?
True
What are the first-line agents to treat familial hypercholesterolemia?
Statins
What is the MOA of a statin?
Inhibition of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase)
-Rate limiting enzyme in cholesterol biosynthesis
-Upregulates LDL receptors in the liver
Besides lowering LDL, what else do statins do?
-Modest effect on lowering TG levels
-Raise HDL levels
What is the expected effect on the LDL cholesterol lowering with a statin dependent on?
-Dose
-Intensity
What is the mainstay of treatment in familial chylomicronemia?
-Fat restricted diet
-Can use statin or fibrate as an adjunct to lower TG levels
What is an AR condition characterized by severe hypertriglyceridemia with serum TG levels >1000?
Familial chylomicronemia
Patients with familial chylomicronemia have a genetically mediated deficiency of what?
Lipoprotein lipase
What is recommended to prevent pancreatitis and is the mainstay of therapy for familial chylomicronemia?
-Strict adherence to a diet regimen limiting fat intake to <10-15% of total caloric intake (15-20g/day)
-Avoidance of alcohol
-Limiting simple, refined carbohydrates
What are the effects of NSAIDs on PGE?
NSAIDs reduce the production of PGE2- this is necessary to maintain patency of the fetal ductus arteriosus
MOA of NSAIDs?
Cyclooxygenase inhibitor
Where does the fetal ductus arteriosus connect?
From the PA to the descending aorta
Describe the purpose of the fetal ductus arteriosus?
-Lack of gas exchange in the lungs in utero leads to a consequently elevated PVR
-Ductus arteriosus provides egress from the right heart into the systemic circulation (where RV output can be sent to placenta for gas exchange)
What % of the combined cardiac output is ejected by the RV?
60%
-Majority is directed through the ductus arteriosus and a small volume goes to the branch PAs with that volume increasing over gestation
True or False: Restriction of the ductus arteriosus in utero can have serious and potentially deadly hemodynamic consequencyes?
True
True or False: Constriction of the ductus arteriosus is likely more common than complete closure?
True
What causes constriction or complete closure of the ductus arteriosus?
-Extrinsic agents that have been ingested by Mom
-Most well-known are NSAIDs (ibuprofen, indomethacin, ASA)
-Less well known: Sympathomimetic drugs like pseudoephedrine, yerba mate tea, various herbal remedies
*Sometimes etiology is unknown
What are the effects of constriction or complete premature closure of the ductus arteriosus?
-Increased afterload to the RV
-Results in dilation and hypertrophy of the RV and TR
-Most concerning- these changes can result in right sided ventricular systolic dysfunction and right sided heart failure leading to hydrops and fetal death
-Increased volume delivered to PAs can cause muscularization of pulmonary vasculature with long-term elevation of PVR and PPHN
-Changes can reduce volume of blood ejected via RV and increase in R-L atrial shunting (In some patients, this can cause RV hypoplasia and PS or PA)
What is seen on fetal echo in ductal construction?
-Dilated RV
-TR
-Narrowed ductus arteriosus with increased systolic/diastolic velocities and Doppler pattern similar to what is seen in CoA
What should be done for fetal patients with ductal constriction?
-Detailed history to identify causative agent and stop its ingestion
-Monitoring for hydrops
-Consider early delivery- will decrease PVR and relieve afterload on right heart
How is postnatal diagnosis of ductal constriction suggested?
No visualization of a ductus arteriosus in the 1st 24 hours in the above clinical settings
True or False: Lamotrigine is a new antiepileptic drug that has a low teratogenicity profile?
True
True or False: In general, antiepileptic drugs are throught to increase risk for major birth defects, but the specific increased risk for CHD is low?
True
Fetal exposure to ACEi (like lisinopril) in the 2nd and 3rd trimester is associated with what?
Fetal renal failure, oligohydramnios and death
What does prenatal exposure to lithium increase the risk of?
Right heart disease, specifically Ebstein anomaly of the tricuspid valve
Constriction of the fetal ductus arteriosus is most often caused by what?
Ingestion of an extrinsic agent such as an NSAID (ibuprofen or indomethacin), pseudoephedrine and herbal agents
Fetal ductal arteriosus constriction can result in what prenatal problems?
-TR
-RV dilation and failure
-Hydrops
-Fetal death
What are the postnatal effects of a constricted fetal ductus arteriosus due to?
Muscularization of the pulmonary vascular bed resulting in persistently elevated PVR
What is the differential diagnosis for a narrow complex short RP tachycardia?
-SVT (AVRT or typical AVNRT)
-Junctional tachycardia
If there is a tachycardia in a neonate that terminates abruptly with vagal maneuvers, what type is most likely to be?
SVT
In infants, what is the most common mechanism of SVT?
AVRT caused by an accessory pathway (concealed or manifest)
True or False: AVNRT is less commonly the cause of SVT in an infant?
True
True or False: Junctional tachycardia is unlikely to convert with vagal maneuvers?
True
In cases of junctional tachycardia, what is true about the arrhythmia?
Tends to be recalcitrant
Why is there an increased concern that infants might not receive care for SVT until they have developed cardiac dysfunction?
They can’t communicate when they are having SVT
*Can have a higher morbidity and mortality compared with older children and adults with SVT
What is the consensus among pediatric cardiologists for the management of SVT in infants?
Medically treat infants with documented SVT to prevent arrhythmia recurrence
What are the most common antiarrhythmics used in infants with SVT?
-B-Blockers
-Digoxin (in absence of preexcitation)
Besides beta blockers and digoxin, what medication can also be considered as a first-line agent for older patients with SVT?
CCB
When is amiodarone used in the management of SVT?
As a 2nd or 3rd line agent… carries a significant potential for adverse effects
Why is an EP study and ablation not a first line option in infants with SVT?
Most infants with SVT will have spontaneous resolution of their tachycardia during their first year after birth
Which infants with SVT be require an ablation to be considered?
Those with recalcitrant SVT that fails multiple drug management and is hemodynamically significant
The risks of ablation are significantly higher in patients who weight < what?
15kg
What are some of the risks with ablation in a patient <15kg?
-Perforation
-AV node injury
What are causes of a short RP tachycardia?
-AVRT
-Typical AVNRT
What are the most common first-line agents for the management of SVT in infants?
-B-blockers
-Digoxin (if no preexcitation)
EP studies and ablation can be considered as 1st line treatment for SVT once patients weight > what?
15kg
True or False: Cardiac abnormalities in Turner syndrome (XO and mosaic variants) are common affecting more than half of all girls and women with Turner syndrome?
True
When is echo done for patients with Turner’s?
At time of diagnosis (usually in childhood)
What things might echo miss for a patients with Turner’s?
-PAPVR
-Aortic dilation or elongation
What testing facilitates anatomical and physiologic assessment of cardiothoracic structures that may be abnormal in girls with Turner syndrome, but missed on screening echo?
MRI/MRA (no ionizing radiation
Besides echo, what imaging is recommended for girls and young women with Turner syndrome to under?
Cardiac MRI once they reach the age they will no longer require sedation
PAPVR has been reported in what % of girls with Tuner syndrome?
3-16%
*But because it is rare otherwise, the RR of PAPVR in Turner v. the normal population is high (300:1)
Besides visualization of PAPVR, what are some other signs by MRI that there is PAPVR?
-Increased flows in the low SVC v. high SVC
-Increased flow across the TV compared to MV
-Increased flow across the PV compared with the AV
-Increased Qp:Qs
-RV SV that is twice the LV SV
-RV dilation
An ASD is seen in what % of girls with Turner syndrome?
2-5%
In an isolated PDA, is there higher flow across the MV v. TV on MRI?
Mitral
In an isolated PDA, is there higher flow across the AV or PV?
AV
In a VSD, is there higher flow across the MV v. TV on MRI?
Mitral
In a VSD, is there higher flow across the AV or PV?
PV
In young teens with Turner syndrome, what is recommended to assess for occult CHD like pulmonary venous anomalies and aortic dilation, even in those previously reported to have had normal echo findings?
MRI
True or False: CMR with phase-contrast flow techniques can be used to quantify cardiac shunt without the need for cardiac cath?
True
What are the most prevalent types of CHD in Turners?
-Bicuspid AoV
-CoA
-PAPVR
-VSD
-ASD
Describe the location of the conduction system in Ebstein
-Normal conduction system had normal location and structure of the AV node, bundle of His and LBBB
-Compact AV node may be displaced towards the coronary sinus os in the Koch triangle
Most patients with Ebstein hearts will have what on their ECG in the absence of preexcitation?
RBBB (71-94%)
What causes the RBBB seen on many Ebstein patients ECGs?
-Multiple congenital abnormalities of the RBB (atresia, short length, narrow caliber, fibrosis)
-Electrically abnormal tissue of the atrialized RV
Besides RBBB, what else can be seen on ECG in Ebstein patients in the absence of preexcitation?
First-degree AB block
What causes first degree AV block in Ebstein patients?
Long interatrial conduction time secondary to RA enlargement
Patients with Ebstein anomaly are predisposed to what?
-Supraventricular and ventricular arrhythmias
-Risk of SVD
What are the most common type of arrhythmias in Ebstein patients?
Supraventricular due to AP pathways (10-38%)
Almost all AP in Ebstein patients are on what side?
Right
True or False: Nearly half of the patients with Ebstein anomaly with AP have multiple APs
True
More than 75% of the APs in Ebstein anomaly are capable of what?
Antegrade conduction- Manifest as preexcitation on ECG (suggestive of WPW)
What happens in a patient with Ebstein who has a right sided AP that fuses with an underlying RBBB?
QRS complex can become pseudonormalized, preexcitation may be subtle and RBBB may not be as evidence
Absence of RBBB in a patient with Ebstein anomaly should raise suspicion for what?
Preexcitation
Successful ablation of a right sided accessory pathway with antegrade conduction should show what?
Underlying RBBB
True or False: Catheter ablation of accessory pathways in patients with Ebstein anomaly is challenging with recurrence rates as high as 20-40%
True
-Fractionated ow amplitude ventricular ECGs from the atrialized RV
-Presence of multiple APs
-Dilated RA
-Difficulty identifying the true AV groove making catheter navigation difficult (this is thin which increases risk of RCA injury and may also have ridge tissue)
Besides AP-mediated SVT (orthodromic and antidromic), Ebstein patients may also have SVT mediated by what?
-Atriofascicular (Mahaim) fibers (5%)
-AVNRT (8-13%)
What is a potential substrate for ventricular tachycardia in Ebstein patients?
Abnormal atrialized RV tissue
Besides the intrinsic rhythm abnormalities in Ebstein patients, they are also prone to develop what after surgery?
Atrial macro reentry tachycardia, focal atrial tachycardia, atrial fibrillation, polymorphic VT
Most patients with Ebstein anomaly have what on their baseline ECG in the absence of preexcitation?
RBBB
Of all the CHD, what has the highest incidence of APs
Ebstein
75% of APs in Ebstein are what type?
Manifest (WPW) and almost always right sided
The absence of RBBB in patients with an Ebstein anomaly should raise suspicion for what?
Preexcitation
A successful ablation of a right-sided AP with antegrade conduction in a patient with Ebstein exposes what?
Underlying RBBB
What are the differences between a true positive, true negative, false positive and false negative?
-True Positive: Tests positive, has disease
-True Negative: Tests negative, doesn’t have disease
-False Positive: Tests positive, doesn’t have disease
-False Negative: Tests negative, has disease
What is the proportion of patients who truly have the disease who test positive?
Sensitivity
What does sensitivity represent?
Chance of accurately ruling in a disease using the test
How is sensitivity calculated?
Proportion of true disease + patients (T+ and F-) that have a positive result on the screening test
What is the equation for sensitivity?
TP/(TP+FN) * 100
What is the proportion of subjects who truly don’t have the disease who test negative?
Specificity
What does specificity represent?
Chance of accurately ruling out a disease using a negative result on a screening test
How is specificity calculated?
Proportion of true disease-negative patients (true negatives and false positives) that have a negative result on the screening test)
What is the equation for specificity?
TN/(TN + FP) * 100
What is the chance of a patient with a positive result truly having disease?
PPV
What is the equation for PPV?
TP/(TP + FP) * 100
What is the chance of a patient with a negative result truly not having the disease?
NPV
What is the equation for NPV?
TN/(TN + FN) * 100
In a 2x2 table, what goes on the X and Y axis?
-X: Disease +/-
-Y: Test +/-
In an umbilical artery Doppler on fetal echo, what does systolic pulsatile flow above the baseline represent?
Fetal HR
An estimated _% of CO is sent to the placenta for gas exchange?
30
True or False: A UA Doppler in which diastolic flow briefly reverses is normal?
False
What type of resistor is a healthy placenta?
Low- should easily receive fetal blood flow (continuous antegrade flow in the UA)
What should be seen on UA Doppler?
Continuous antegrade flow
What accounts for the normal low fetal SVR?
Placental being a low resistor and easily receiving fetal blood flow
What happens to the SVR after birth?
Arises abruptly once umbilical cord is clamped
Absent or reversed end diastolic flow velocity in the umbilical artery is a sign of what?
Increased impedance in the placenta vascular bed
Absent or reversed end diastolic flow velocity in the umbilical artery is a sign of what?
Placental insufficiency related to vascular maldevelopment
True or False: Absent or reversed end diastolic flow velocity in the UA is associated with an increased risk of perinatal mortality?
True
Absent or reversed end-diastolic flow velocity is a frequent finding in what?
Fetal growth restriction- This has important implications for pregnancy management including consideration and timing of premature delivery
True or False: Abnormal UA Doppler has increased prevalence in fetal chromosomal abnormalities and some congenital malformations?
True
If a fetus is measuring <10th percentile, what should you consider?
Fetal growth restriction
True or False: Noninvasive prenatal testing (NIPT) has a high sensitivity for aneuploidies (T21, T13, T18)
True- A negative screen is reassuring regarding these abnormalities
What has been described on fetal echo in severe Ebstein anomaly/tricuspid valve dysplasia and fetal complete heart block?
-Abnormalities in UA Doppler- physiological explanations include circular shunt physiology (Ebstein) and prolongation of the diastolic phase of the cardiac cycle (heart block)
-Presence of abnormal UA Doppler is associated with poor outcome
What extracardiac Doppler assessments are important for the evaluation of fetal hemodynamics?
-UA
-UV
-Ductus venosus
-MCA
-Abnormal patterns alert to derangements in the fetal circulation that may be of diagnostic and prognostic significance
UA Doppler patterns provide insight into what?
Fetal circulation and well-being
Describe a normal UA Doppler
-Systolic pulsatile upstrokes
-Continuous antegrade diastolic flow
Absent end-diastolic or reversed end-diastolic flow velocity in the UA are consistent with what?
Placental insufficiency (predict adverse perinatal outcomes)
What are abnormal features of a ductus venosus Doppler?
A wave absence or reversal
What are abnormal features of an umbilical vein Doppler?
-UV pulsations
-Lower velocity
What are abnormal features of an umbilical artery Doppler?
-Absent/reversed end diastolic flow
-Elevated pulsatility index
What is the relationship of the aorta and pulmonary artery in d-TGA?
-Aorta is anterior and rightward
-Pulmonary artery is posterior and leftward
What defines TGA?
Connection of the great arteries to their respective ventricles (not solely on the arrangement of the great arteries in space)
What is it called when the connections of the great arteries result in the systemic and pulmonary circulations being in parallel rather than in series?
d-TGA
Patients with d-TGA are dependent on what for survival?
-Mixing and shunting (either at atrial or ventricular level)
-Shunting (through PDA or bronchial collaterals)
Besides PGE and possible BAS, what should also be considered for newborns with d-TGA and cardiorespiratory impairment or severe hypoxemia in babies with d-TGA and IVS?
-Intubation
-Correction of metabolic derangements and acidosis
-Administer O2
What is the benefit of PGE in d-TGA?
Keep the PDA open to promote volume loading of the LA and atrial level mixing
What is a good starting dose for PGE in d-TGA?
-0.0125ug/kg/min
-Low dose allows for ducal patency, but minimizing the risk of PGE associated apnea and need for intubation
-Higher doses may be needed if PDA is small
Why is a PDA bidirectional in the newborn period?
High PVR
In a patient with d-TGA, what might need done to ensure proper mixing?
BAS (especially if there is a restrictive atrial level communication)
True or False: For infants with d-TGA, performing a BAS will allow the PGE to be stopped
True, but for some infants even if the BAS is technically effective, they may still require PGE to improve effective pulmonary blood flow
True or False: In patients with d-TGA and VSD, adequate mixing may not occur at the ventricular level and a BAS may still be required?
True
What characterizes d-TGA?
Parallel circulation (patients are dependent on adequate mixing for survival
What is needed soon after diagnosis in order for adequate mixing to occur in patients with d-TGA with a restrictive atrial level communication?
BAS
What is the most common cardiomyopathy seen in children?
DCM
What is characterized by left ventricular dilation and systolic dysfunction?
DCM
How does DCM present?
Varies widely: Some patients are asymptomatic (detected after screening due to family history), other may be in acute decompensated heart failure
What are the two ways to classify patients in acute heart failure based on symptoms?
-Congestion (wet or dry)
-Adequacy of perfusion (warm or old)
What is the classification of a patient presenting in acute decompensated heart failure who has elevated atrial pressure (high CVP), tachypnea, hepatomegaly, CXR with cardiomegaly, pulmonary edema, pleural effusions, hypotension and cool extremities?
Wet and cold
What are the overall goals of management for someone presenting in “wet and cold” acute decompensated heart failure?
-Symptomatic relief
-Prevention of end-organ dysfunction (optimize fluid status and CO)
What is important therapy to reduce right and left ventricular filling pressure in the setting of pulmonary edema?
Diuresis
Under what circumstance do you need to use diuretics cautiously in a patient with heart failure?
Concomitant low CO- diuretics have the potential to reduce preload and worsen end-organ perfusion
Besides diuretics, what can be done for patients with respiratory symptoms from pulmonary edema?
-O2
-Noninvasive or invasive PPV
How can mechanical ventilatory support help a patient in decompensated heart failure?
-Decrease work of breathing
-Decrease LV afterload
What is a risk of mechanical ventilatory support in patients with acute decompensated heart failure?
Significant hemodynamic instability with the sedation needed to intubate
What medications have a clear role in the stabilization of patients with circulatory compromise, but should be used with caution given proarrhythmic effects?
Inotropes
What medications result in a reduction in the rate and force of myocardial contraction, heart and BP and are thus contradicted in the setting of acute decompensated heart failure?
B-blockers
When should B-blockers be used in heart failure?
Chronic management, they are contradicted in the setting of acute decompensated heart failure
Why is neurohumoral modulation an important tenet of therapy for chronic heart failure?
There is activation of the sympathetic nervous system ad upregulation of the renin-angiotensin-aldosterone system (RAAS) that results in myocardial dysfunction and adverse cardiac remodeling
Once acute symptomatic relief and adequate CO are achieved for patients in acute heart failure, what should be initiated as part of chronic management for neurohumoral modulation of the RAAS?
ACEi or ARB
What medication is used in chronic heart failure management to mitigate the effects of sympathetic nervous system activation in heart failure?
B-blocker
What type of B-blockers have a relative selectivity for B1 adrenergic receptors found in the heart?
2nd generation- metoprolol
What type of B-blockers are nonselective for B-receptors with additional a-adrenergic blocking activity that results in cardiac reverse remodeling effects?
3rd generation- carvedilol
What medication used in chronic heart failure therapy has the ability to oppose adrenergic stimulation at multiple sites?
Carvedilol
What are adverse effects from B-blockers in pediatric patients with heart failure?
Fatigue, hypotension, dizziness, headaches, depression, mood disorder
What are some contraindications to B-blockers?
Severe bradycardia, high-grade heart block, hypotension, acute decompensated heart failure, bronchospasm/asthma history (relative contraindication- 2nd generation agents with a relative selectivity for B1-adrenergic receptors may be cautiously considered when the history of asthma is mild)
Which patients are at risk for hypoglycemia caused by a reduction in hepatic gluconeogenesis when B-blockers are used and should be monitored accordingly?
Infants with poor enteral intake
What medication is contraindicated in the setting of acute decompensated heart failure?
B-blockers
What makes B-blockers useful in the management of chronic heart failure?
Antagonism of the adverse neurohumoral modulation seen in heart failure
Why is carvedilol a useful medication in chronic heart failure therapy?
Oppose adrenergic stimulation at multiple sites in addition to its B-receptor blockade
Irregularly irregular narrow complex tachycardia?
Atrial fibrillation
What is the Ashman phenomenon?
-Aberrant conduction secondary to a change in the tachycardia cycle length
-Reason for the aberrancy is because the refractory period in cardiac cells is related to the preceding R-R interval
-Usually occurs when there is a short R-R interval that follows a long R-R interval
Atrial fibrillation most commonly occurs in pediatric patients who have what?
-Associated structural heart disease
-WPW
In patients without structural heart disease, some of the most common causes of atrial fibrillation include what?
-Thyroid abnormalities
-Use of drugs of abuse
Prevalence of atrial fibrillation in the young has been shown to be higher in which patients?
-Male
-Obese
Some patients that are classified as having “lone atrial fibrillation” have been found to have what as the precipitating cause of their atrial fibrillation?
SVT (AVNRT or concealed accessory pathways)
What is the mechanism for SVT being the precipitating cause for atrial fibrillation?
-SVT degenerates into atrial fibrillation
-Ablation of the underlying arrhythmia substrate has been shown to decrease risk of recurrence of atrial fibrillation
What is the risk of recurrence in atrial fibrillation?
39% over 2 year follow-up period
What features are associated with a higher risk of recurrence of atrial fibrillation?
-Family history of atrial fibrillation in a first degree relative
-Prolonged PR interval at baseline
Patients presenting with atrial fibrillation should be evaluated for what?
-Thyroid abnormalities
-Drugs of abuse
-Structural heart disease
What can be the cause of atrial fibrillation in a subset of patients?
SVT (AVNRT or concealed accessory pathways)
What increases the risk of recurrent atrial fibrillation?
-1st degree relative with atrial fibrillation
-Prolonged PR interval at baseline
A persistent PDA after birth is more common in what neonates?
Premature (v. those born at term)
A persistent PDA can result in what?
Significant L-R shunt
What determines the clinical significance of a PDA?
Volume of blood shunting across the PDA and degree of pressure restriction provided by the PDA between the aorta and PA over time
What are the effects of a significant ductal shunt?
-Volume load on the pulmonary vascular bed and left heart
-CHF with progressive dilation of LA/LV
Why is increased pulmonary blood flow from a PDA a problem in a premature infant
-Increased pulmonary blood flow particularly deleterious to the immature pulmonary vascular bed
-Results in pulmonary edema, reduced lung compliance, ineffective gas exchange
-Often results in need for high ventilator settings and risk of further lung damage
What is the recommendation for a hemodynamically significant PDA?
Can try medical therapy with diuretics, but definitive therapy with PDA closure is often indicated
What are options for closure of a PDA?
-Pharmacologic: Indomethacin, ibuprofen, acetaminophen
-Procedural: Percutaneous, surgical ligation
What are some of the potential adverse effects of pharmacologic closure of a PDA?
-NEC
-Kidney injury
What is considered the standard of care for PDA that doesn’t close with pharmacologic intervention?
Percutaneous PDA device closure
What is commonly seen after percutaneous closure of a PDA or surgical ligation of a PDA?
-Post-ligation cardiac syndrome
-Dilated LA/LV with mildly depressed systolic function
-Patients at risk for low CO (can occur quickly after intervention)
-Develop hypotension and circulatory insufficiency
What are risk factors for post-ligation cardiac syndrome?
-Large PDA
-Earlier age at ligation
-Lower estimated gestational age
-Lower birth weight
-Significant degree of pre-intervention cardiorespiratory support
What causes post-ligation cardiac syndrome?
-Myocardial dysfunction and a dysregulation of vascular tone because of a sudden increase in LV afterload and decrease in LV preload
-Decrease of excessive volume preload and reduction in LA filling pressure results in ventricular contractility (Frank-Starling)
-Major culprit is sudden increase in afterload because LV is no longer exposed to low-resistance pulmonary vascular bed
Why are premature infants at increased risk for post-ligation cardiac syndrome after PDA closure?
Premature myocardium is unable to tolerate increase in SVR from PDA closure, get resultant increase in LV systolic wall stress and decrease in LV shortening fraction and velocity of circumferential fiber shortening
True or False: Although echo post-PDA closure can show LV systolic dysfunction, clinically relevant post-ligation cardiac syndrome is uncommon
True
Why is there a reduced likelihood of post-ligation cardiac syndrome in patients who undergo percutaneous PDA closure?
Typically older and larger than those undergoing surgical ligation
True or False: There is a lower incidence of post-ligation cardiac syndrome after percutaneous PDA closure in infants with extremely low birth weight compared with surgical ligation?
True- Percutaneous less invasive procedure likely has specific benefit itself
What are the risks associated with transcatheter PDA device closure?
-Vascular damage (loss of femoral artery pulse in small infants)
-Device embolization
-Obstruction across the LPA or descending Ao by device
A PDA results in what that is deleterious to the immature pulmonary vascular bed of a premature infant?
Increased pulmonary blood flow
What is well described after PDA ligation surgery resulting in systemic hypotension and circulatory insufficiency?
Post-ligation cardiac syndrome
What is post-ligation cardiac syndrome?
Involves myocardial dysfunction and a dysregulation of vascular tone because of a sudden increase in LV afterload and decrease in LV preload after ligation- particularly poorly tolerated by premature myocardium
What has largely replaced surgical ligation as the definitive therapy for PDA closure and can be considered standard of care when nonpharmacologic intervention is required, even in very small infants?
Percutaneous PDA device closure
True or False: Clinically relevant post-ligation cardiac syndrome is less common in infants with extremely low birth weights after device closure compared with surgical ligation?
True
What accounts for 80-85% of cases of LVOTO?
Valvular aortic stenosis
Describe the mature aortic valve
3 cusps/leaflets, 3 commissures
What is the most common abnormality of the aortic valve leading to aortic stenosis?
Partial or complete fusion of the valve cusps
List in order from most common to least fusion patterns of the aortic valve?
-Most: Left and right
-Middle: Right and non
-Least: Left and non
Doppler gradients provide accurate estimates of the severity of valvular stenosis except in what situations?
-Decreased CO
-Multiple levels of obstruction
-Pop-off like a VSD
*All can result in a lower Doppler gradient despite the presence of a significant stenosis
What is considered the gold standard to measure the gradient across the aortic valve?
Cath
Describe the difference between peak to peak gradients measured in the cath lab, peak instantaneous pressure gradients measured by spectral Doppler and mean Doppler gradients
-Measurements reflect different physiologic parameters
-Peak instantaneous pressure gradient measured by spectral Doppler is higher than the peak-peak gradient measured in the cath lab
-Mean Doppler gradients on echo correlate more closely with the peak-peak gradients measured in the cath lab
What are the guidelines for treatment of AS based upon?
-Cath derived peak to peak gradients
-Clinical symptoms
-ECG changes
A cath peak to peak gradient > what (even if asymptomatic) meets the criteria for balloon aortic valvuloplasty?
50
In symptomatic patients (angina or syncope), patients with resting or exercise-induced ECG changes (ST-T changes), or in patients planning to become pregnant or participate in competitive sports, a gradient > what is recommended as the cutoff for balloon aortic valvuloplasty?
40
Under what circumstance is balloon aortic valvuloplasty indicated regardless of measured pressure gradients?
Infants with valvular AS and depressed LV function or with critical valvar stenosis (requiring patency of the PDA for adequate systemic perfusion)
What is often used in adults to guide decisions about aortic valvuloplasty when baseline gradients are low due to low cardiac output?
Drug challenge using dobutamine- but this challenge is not required in infants and children
Balloon aortic valvuloplasty is indicated regardless of pressure gradients in what situations?
-Valvar AS and depressed LV systolic function
-Critical valvar stenosis (requiring the patency of the ductus arteriosus for adequate systemic perfusion)
Which is higher, peak instantaneous gradient on the echo evaluation or peak-peak gradient obtained in the cath lab?
Peak instantaneous gradient on echo
What does a peak to peak gradient in the cath lab correlate more closely with on echo in valvular AS, mean gradient or peak instantaneous gradient?
Mean gradient
What are skin lesions caused by abnormal deposition of lipids in the subcutaneous tissue and tendons?
Xanthomas
Where are tendinous xanthomas usually located?
Extensor aspects of joints
Where are subcutaneous xanthomas often found?
-Palmar aspects
-Interdigital spaces
-Around the eyes
What are corneal arcus?
Lipid deposit in the cornea
What is seen on skin biopsy of xanthomas?
Cholesterol crystals in the center surrounded by fibrosis and foamy macrophages
The presence of cutaneous or tendinous xanthomas in a young child or adolescent should raise suspicion for what?
Inherited hyperlipidemia
A mutation in LDL receptor gene causes what?
Familial hypercholesterolemia
What is the typical lipid profile of a patient with familial hypercholesterolemia?
-Markedly elevated LFL
-Mildly elevated TG
-Normal HDL
What are some of the genes associated with familial hypercholesterolemia?
-LDLR (LDL receptor)
-Apo-B (apolipoprotein-b)
-PCSK9 (pro-protein convertase subtilisin/kexin type 9
-LDLRAP1 (LDL receptor adapter protein 1)
How can patients with familial hypercholesterolemia categorized?
-Receptor defective (2-25% residual activity)
-LDL receptor deficient (<2% residual activity)
What are the criterial for the clinical diagnosis of familial hypercholesterolemia?
-Genetic confirmation of 2 mutant alleles at the LDR, APOB, PCSK9 or LDLRAP1 gene loci
-Untreated LDLC level >500mg/dL (13.0mmol/L) or a treated LDLC level >300mg/dL (7.8mmol/L)
-In the presence of cutaneous or tendon xanthomas before the age of 10 years -Untreated elevated LDL levels in both the parents
True or False: The usual lipid-lowering agents like statins, ezetimibe and bile acid-binding resins are ineffective in obtaining a significant reduction in the LDL-C levels
True
What are 3 drugs are approved by the FDA for management of familial hypercholesterolemia (homozygous) in children >12 and adults?
-Lomitapide (microsomal transport protein inhibitor)
-Mipomersen (antisense oligonucleotide against the apo(B) MRI
-Evinacumab (monoclonal antibody that inhibits angiopoietin-like protein 3 (ANGPTL3)
What is one medication approved by the FDA for management of familial hypercholesterolemia (homozygous) in children >10 and adults?
Evolocumab (PCSK9 inhibitor)
Besides lomitapide, mipomersen, evolocumab and evinacumab what are some drugs currently being studied for use in pediatrics in familial hypercholesterolemia?
Inclisiran (small interfering RNA molectule (siRNA) which inhibits PCSK9 mRNA translation- FDA approved in adults, pediatric trials underway)
What is sitosterolemia?
Disorder of lipid metabolism that can present with cutaneous and tendinous xanthomas in youth
How does sitosterolemia differ from familial hyperlipidemia?
-AR with mutations in the ABCG5 and ABCG8 genes
-Typically have normal LDL cholesterol levels
-Characterized by markedly elevated levels of plant sterols in the blood with poor response to statins
What is a first-line drug for sitosterolemia?
Ezetimibe (followed by bile acid binding resins and avoidance of plant sterols
What causes neurofibromatosis?
Mutation in the tumor suppressor NF1 gene
Neurofibromas + Axillary/Inguinal freckling?
Neurofibromatosis (mutation in tumor suppressor NF1 gene)
What type of CHD is seen in neurofibromatosis?
-Pulmonary valve stenosis
-Mitral valve prolapse
-Septal defects
-HCM
Mutations in TSC1 or TSC2 genes cause what?
Tuberous sclerosis complex
What findings are seen in tuberous sclerosis complex?
-Angiofibromas
-Shagreen patch
-Multiple café-au-lait spots
-Cardiac rhabdomyomas
What causes Fabry disease?
Mutation in alpha galactosidase A
What is Fabry disease?
X-lined recessive lysosomal storage disorder (gene mutation causes accumulation of glycosphingolipids in the vascular endothelium, smooth muscle, heart and other organs)
Angiokeratomas (1-2mm red papules) on trunk, perineal area and oral mucosa
Fabry disease
What are the heart findings seen in Fabry disease?
-LVH (myocardial accumulation of the sphingolipids)
-Valvular abnormalities
-Systemic HTN
-Atherosclerotic disease of coronary and cerebral arteries
The presence of cutaneous or tendinous xanthomas in a young child or adolescent should raise suspicion for what?
Inherited hyperlipidemia
What are the most common genetic mutations in patients with familial hypercholesterolemia?
-LDL receptor gene
-apo-B
-PCSK9
-LDLRAP1
True or False: The usual lipid lowering agents like statins, ezetimibe, and bile acid binding resin are ineffective in obtaining a significant reduction in the LDL cholesterol levels in homozygous familial hypercholesterolemia?
True
What are some of the promising new agents in lipid lowering in homozygous familial hypercholesterolemia?
-PCSK9 inhibitors, ANGPTL3 inhibitors, Inclisiran
In a patient with single ventricle physiology immediately after stage I palliation with a systemic to pulmonary shunt, what governs the balance of pulmonary v. systemic blood flow (Qp:Qs)?
PVR and SVR
What is the goal for a stage I single ventricle patient and how is this achieved?
-Balanced circulation with an equal distribution of blood flow between the pulmonary and systemic vascular beds
-Manipulation in pulmonary or systemic vascular resistance
What is needed to calculate a patient’s Qp:Qs?
-Systemic venous saturation
-Systemic arterial saturation
-Pulmonary artery saturation
-Pulmonary venous saturation
In a patient with stage I single ventricle heart disease, what assumptions can be made regarding Qp:Qs?
-Only source of pulmonary blood flow is shunt which receives blood flow from systemic circulation so the saturation in the PA is the same as the systemic artery
-For a patient on 21% FiO2 with normal CXR, can assume that the pulmonary veins are fully saturated at close to 100%
Equation for Qp/Qs?
(Systemic artery saturation – Systemic vein saturation) / (Pulmonary vein saturation – Pulmonary artery saturation)
What are some ways you can get a sense of a patient’s cardiac output?
-Exam: Is patients warm/well perfused, good capillary refill, bounding pulses
-AV saturation difference
-Lactate level
In a post-op cardiac patient, what can cause vasodilation leading to low SVR?
Rapid rewarming after CPB or peripheral vasodilators (like low-dose epinephrine and milrinone)
How does vasopressin work?
Neurohypophysial hormone that directly stimulates smooth muscle V1 receptors resulting in vasoconstriction
What is the half life of vasopressin?
10-20 minutes
After starting vasopressin, you get a steady state of infusion in how long?
15-20 minutes
What are the main effects of vasopressin?
Vasoconstriction and increased SVR
What would be the effect of increased SVR in a stage 1 single ventricle patient?
Increased pulmonary blood flow through the shunt
True or False: If you increase in SVR in a hypoxic stage 1 single ventricle, you would expect to see fairly immediate rise in O2 saturation, PaO2 and BP?
True
What are the overall effects of milrinone on SVR?
Increase
What is the half-life of milrinone in an infant?
2 hours- would take 2-4 hours before you would see an effect
True or False: Epinephrine at 0.05ug/kg/min would increase BP if the main issue was decreased CO?
True
What effects of epinephrine predominate at 0.05ug/kg/min?
B-agonist effects
What effects of epinephrine would help to increase SVR?
Alpha-agonist
What are the effects of lower dose v. higher dose epinephrine on SVR?
-Lower dose (0.05ug/kg/min), B-agonist effects predominant, not likely to increase SVR
-Higher doses, alpha-agonist effects predominate, increase SVR
Effect of iNO on PVR?
Decrease
In addition to lowering PVR, what other effect does sildenafil have?
Decreases SVR- can cause hypotension (need to be cautious with use in single ventricles especially if trying to augment Qp:Qs)
In a stage 1 single ventricle with low SpO2 and normal CO, what could be the underlying pathophysiology?
Low SVR
In a stage 1 single ventricle with increased SpO2 and poor perfusion/CO, what could be the underlying pathophysiology?
Decreased PVR
How can prolonged low CO after CPB lead to AKI?
Suboptimal hemodynamics lead to a low renal perfusion pressure, decreased GFR and decreased urine output
What are the goals in the ICU for a patient in low CO state after CPB?
Preserve end-organ function and perfusion to prevent injury and promote recovery as the myocardial function recovers
What is stage 2 AKI by pediatric kidney disease improving global outcomes criteria?
<0.5mL/kg/hr of UOP over 12 hours
What are some of the categories to evaluate to diagnose AKI?
-Urine output
-Rise in creatinine above baseline
-Emerging biomarkers (Neutrophil gelatinase associated lipocalin (NGAL) or cystatin-C)
What should be done to promote a higher renal perfusion pressure in a patient with high venous pressures and low urine output?
Reduce CVP- fluid removal
What can help to augment fluid removal when a patient is diuretic resistant?
Advanced renal replacement therapies
Why is post-op fluid removal associated with better outcomes?
-Improve end organ perfusion pressure
-Improve cardiac function by improving the Starling curve mechanics
What are risk factors for cardiac surgery-associated AKI?
-Neonatal age
-Lower weight
-Exposure to CPB
-Exposure to nephrotoxic agents
-Low CO syndrome
-Higher preoperative illness severity
What is often the first-line renal replacement therapy when other medical therapies have failed in neonates with cardiac surgery associated AKI?
Peritoneal dialysis (some center empirically place a PD drain in certain neonates in OR)
What are 2 ways a PD drain can be used?
-Passive drain for fluid removal
-Dialysate fluid instilled and dwelled prior to draining to perform dialysis
True or False: In many cases, a patient will only require a few says of peritoneal dialysis before AKI resolves in cardiac surgery associated AKI?
True
What can be used to augment vasoactive therapies in the post-op patient (particularly in catecholamine-resistant vasoplegic shock)?
Corticosteroids
True or False: Fluid overload should be avoided and corrected in the context of a patient’s underlying disease to avoid complications and need for increased resource utilization
True
In neonates with diuretic refractory fluid overload in the setting of AKI, what is often a first-line therapy for fluid removal?
Peritoneal dialysis
True or False: A RAA with an aberrant left subclavian artery and a left-sided ductus is an anatomic substrate for vascular ring
True
What is a vascular ring?
Anomaly where the trachea and esophagus are encircled by vascular structures
What are the effects of a vascular ring?
External compression with variable respiratory or GI symptoms depending on the degree of compression
What is the clinical evaluation for a vascular ring driven by?
Patients symptom burden- Majority of postnatally discovered rings are diagnosed in symptomatic patients
In surgical series, what type of vascular ring comprises the largest proportion of cases and why?
Double aortic arch- ring is tighter and compression is more severe (as compared to right aortic arch with an anomalous left subclavian)
What is the most common type of vascular ring seen in prenatal studies?
Right aortic arch with anomalous left subclavian artery (80% v. 20% double aortic arch)
True or False: Patients with right aortic arch and anomalous left subclavian artery are less likely to be symptomatic than double aortic arch?
True- surgical series show more double aortic arch, but prenatal series show more RAA-ALSCA (more people with RAA-ALSCA, but less likely to cause problems and need surgery, lack of significant symptoms postnatally)
*Recent study showed 33% of RAA-ALSCA patients diagnosed in utero had symptoms versus 75% of patients diagnosed in utero with DAA
True or False: Symptom onset is earlier and more severe in double aortic arch than right aortic arch with anomalous left subclavian artery
True
Which type of symptoms, respiratory (stridor, wheezing) or GI (reflux, vomiting, swallowing-related), are more common in double aortic arch?
Respiratory (ratio of 2-4:1)
Surgical repair is indicated for which patients with vascular ring?
Symptomatic (asymptomatic patients can be followed expectantly)
What 2 things does the natural history of vascular ring vary by?
-Anatomic substrate
-Timing of diagnosis (prenatal or postnatal
True or False: A patient with a fetal diagnosis of isolated right aortic arch with an aberrant left subclavian artery is likely to be asymptomatic
True
