PEDS CARDIO

PAS 5420 Clinical Pediatrics — Cardiology

50-Question PANCE-Style Clinical Vignette Practice Exam

South College Atlanta · ATL-2026 · Eva Willauer MMSc PA-C

Topics: Acyanotic CHD (VSD, ASD, AVSD, PDA, Coarctation) · Cyanotic CHD (TOF, TGA, HLHS) · Shunting & Eisenmenger · Murmur Evaluation · Fetal Circulation · CCHD Screening · SBE Prophylaxis · Late Sequelae · Pulmonary Hypertension

PART I — QUESTIONS

Question 1

A 6-week-old male infant is brought in for a well-child visit. His mother reports he sweats profusely during feedings, takes longer than 30 minutes to finish a bottle, and has had two respiratory infections in the past month. His weight is below the 3rd percentile. On exam, HR is 160, RR is 52, and you hear a Grade III/VI harsh pansystolic murmur loudest at the left lower sternal border (LLSB). CXR shows cardiomegaly with increased pulmonary vascularity. What is the most likely diagnosis and the most important long-term complication to prevent?

A. Small VSD; risk of endocarditis

B. Large VSD; pulmonary hypertension from long-standing left-to-right shunt

C. ASD; right ventricular hypertrophy

D. PDA; coarctation of the aorta

Question 2

A 2-day-old full-term newborn has a Grade II/VI medium-pitched pansystolic murmur noted at LLSB during routine nursery exam. She is otherwise asymptomatic — feeding well, pink, no respiratory distress, normal weight gain. Echocardiogram confirms a 2mm VSD. What is the most appropriate management?

A. Immediate surgical repair before discharge

B. Indomethacin to promote spontaneous closure

C. Watchful waiting; nearly all small VSDs close spontaneously

D. Diuretics and inotropes to prevent heart failure

Question 3

A 4-month-old infant with a large VSD is being managed medically pending surgical repair. The pediatric cardiologist explains that surgery should be completed before age 2. The mother asks why surgery cannot wait until the child is older. Which complication is the surgeon primarily trying to prevent?

A. Development of aortic stenosis

B. Pulmonary hypertension from irreversible vascular remodeling

C. Spontaneous closure of the defect

D. Development of an atrial septal defect

Question 4

A 7-year-old girl is referred to you after her school sports physical. The examining PA noted a Grade II/VI systolic ejection murmur in the pulmonic area (second left ICS). The child has no symptoms and exercises without difficulty. On exam you note a wide, fixed split S2. ECG shows right axis deviation. CXR shows mild cardiomegaly with increased pulmonary vascularity. What is the most likely diagnosis and the pathognomonic auscultatory finding?

A. VSD; harsh pansystolic murmur at LLSB

B. ASD; wide fixed split S2

C. PDA; continuous machinery murmur

D. Pulmonary stenosis; systolic ejection click

Question 5

An 8-month-old boy with Trisomy 21 is brought in for evaluation of failure to thrive, tachypnea, and diaphoresis with feeds. On exam you note a holosystolic murmur with a fixed wide split S2. ECG shows extreme left axis deviation and biventricular hypertrophy. CXR shows four-chamber cardiomegaly with increased pulmonary markings. What is the most likely diagnosis and its genetic association?

A. VSD; associated with Turner syndrome

B. PDA; associated with congenital rubella

C. Common atrioventricular canal (AVSD); strongly associated with Trisomy 21

D. Tetralogy of Fallot; associated with DiGeorge syndrome

Question 6

A 3-week-old premature infant (born at 29 weeks, now 36 weeks corrected age) has been difficult to wean from the ventilator. Nursing notes wide pulse pressure and bounding pulses. On auscultation you hear a rough continuous 'machinery-like' murmur below the left clavicle that peaks at S2 and decrescendos into diastole. What is the diagnosis and the first-line medical treatment?

A. VSD; furosemide and digoxin

B. ASD; watchful waiting

C. PDA; indomethacin (prostaglandin synthesis inhibitor)

D. Coarctation of aorta; prostaglandin E1

Question 7

A 6-week-old full-term female infant is noted to have a widened pulse pressure and bounding peripheral pulses on routine exam. A continuous machinery murmur is heard at the left second intercostal space. CXR shows cardiomegaly and increased pulmonary vasculature. What additional sign would be expected on cardiac exam?

A. Wide fixed split S2

B. Opening snap

C. Narrowly split S2

D. Pericardial friction rub

Question 8

A 14-year-old male is seen for a routine sports physical prior to joining the football team. He has no complaints. On exam, BP in the right arm is 148/92 and BP in the right leg is 98/70. Femoral pulses are absent. A systolic ejection murmur is heard in the left axilla and left back. CXR shows rib notching of the 4th–8th ribs bilaterally and a 'figure of 3' sign on the aortic knob. What is the diagnosis and what must be ruled out in female patients?

A. Hypertrophic cardiomyopathy; rule out Marfan syndrome

B. Coarctation of the aorta; rule out Turner syndrome (XO) in females

C. Aortic stenosis; rule out Williams syndrome

D. PDA; rule out congenital rubella

Question 9

A 5-day-old full-term male infant presents to the ED in cardiogenic shock. He was discharged from the nursery on day 2 appearing well. Now he is pale, cold, and lethargic with HR 180, BP 58/32, and femoral pulses are barely palpable. What is the diagnosis and immediate treatment?

A. Transposition of great arteries; balloon atrial septostomy

B. Coarctation of the aorta; prostaglandin E1 infusion to reopen the ductus

C. Hypoplastic left heart; immediate cardiac surgery

D. Sepsis; broad-spectrum antibiotics

Question 10

An 8-month-old male infant has had progressive cyanosis since age 4 months. He was described as 'pink' in the nursery. On exam, he has digital clubbing, cyanosis at rest, a systolic thrill along the left sternal border, and a Grade III/VI rough systolic murmur at the left sternal border. CXR shows a 'boot-shaped' heart with decreased pulmonary vascularity. ECG shows right axis deviation and RVH. What is the most likely diagnosis?

A. Transposition of the great arteries

B. Hypoplastic left heart syndrome

C. Tetralogy of Fallot

D. Total anomalous pulmonary venous return

Question 11

A 10-month-old girl with known Tetralogy of Fallot is brought in by EMS. Her mother reports she began crying inconsolably, then became deeply cyanotic, limp, and unresponsive. HR is 200. SpO2 is 62% on room air. What is the diagnosis and which INITIAL maneuver is correct?

A. VT; immediate defibrillation

B. Hypercyanotic 'Tet' spell; place the child in a knee-to-chest position and provide supplemental oxygen

C. Pulmonary embolism; anticoagulation

D. Breath-holding spell; reassurance only

Question 12

Which of the following correctly describes the management of Tetralogy of Fallot?

A. Medical management with diuretics and inotropes is first-line

B. Complete repair is NOT possible; only palliative surgery is available

C. Condition is NOT managed medically; diuretics and inotropes increase hypercyanotic spells. Definitive treatment is complete surgical repair between birth and age 2.

D. Medical management with propranolol alone provides adequate long-term control

Question 13

A male neonate is born at 39 weeks via C-section for non-reassuring fetal status. At 6 hours of life, he is deeply cyanotic with SpO2 of 52% on 100% oxygen. He has no respiratory distress and is not in obvious respiratory failure. A murmur may or may not be present. CXR shows an 'egg on a string' cardiac silhouette with increased pulmonary vascular markings. What is the diagnosis and immediate treatment?

A. Tetralogy of Fallot; knee-to-chest positioning

B. Transposition of the great arteries; prostaglandin E1 to maintain ductal patency, then arterial switch operation

C. Respiratory distress syndrome; surfactant therapy

D. Hypoplastic left heart; palliative surgery

Question 14

A neonatologist explains to the parents of a newborn with TGA why their baby 'turned blue' within hours of birth. The parents ask why the baby was alive at all given the heart defect. What fetal structure allowed survival until birth?

A. The mitral valve

B. The tricuspid valve

C. The ductus arteriosus and foramen ovale, which allow mixing between the parallel circulations

D. The ductus venosus

Question 15

A female neonate appears healthy at birth but on day 3 of life develops sudden cardiovascular collapse — pale, cold, acidotic, with no palpable femoral pulses and no detectable BP. She is non-responsive to initial resuscitation. Echocardiography shows near-absent left ventricular cavity, mitral valve atresia, and aortic valve atresia with a hypoplastic ascending aorta. What is the diagnosis, and what is the immediate life-saving medication?

A. Septic shock; broad-spectrum antibiotics

B. Coarctation of the aorta; balloon angioplasty

C. Hypoplastic left heart syndrome; prostaglandin E1 to keep the ductus arteriosus open

D. Transposition of the great arteries; arterial switch operation

Question 16

A 22-year-old woman with an unrepaired large VSD since infancy presents with worsening dyspnea, decreased exercise tolerance, and new-onset cyanosis. Echocardiography shows severe pulmonary hypertension with now right-to-left shunting across the VSD. Her pulmonary vascular resistance is now higher than systemic resistance. What is this condition and what is the treatment option?

A. Pulmonary embolism; anticoagulation and thrombolytics

B. Eisenmenger physiology; the defect is now INOPERABLE — palliation and pulmonary vasodilators

C. Congestive heart failure; diuretics and ACE inhibitors

D. Reactive airway disease; bronchodilators

Question 17

A 16-year-old boy with an unrepaired ASD is evaluated for worsening dyspnea. During evaluation, you learn that in an ASD, blood flows left-to-right across the defect. What drives this direction of flow?

A. Systemic blood pressure is higher than pulmonary pressure in the right atrium

B. Pulmonary vascular resistance is lower than systemic resistance, creating higher pressure in the left atrium than the right

C. The right atrium has a thicker wall and generates higher pressure

D. The mitral valve is open during all phases of the cardiac cycle

Question 18

A 3-year-old girl is brought in for a well-child visit. On auscultation, you hear a Grade II/VI musical or vibratory, high-pitched systolic murmur heard best at the LLSB and apex. The murmur decreases when the child sits up or takes a deep breath and is loudest when she is supine. She has no cyanosis, normal pulse oximetry, no cardiac symptoms, and normal ECG and CXR. What is the most likely diagnosis?

A. VSD — refer to cardiology urgently

B. ASD — order echocardiogram

C. Still's murmur — the most common functional murmur in children aged 2–8

D. PDA — begin indomethacin

Question 19

A 3-day-old full-term newborn has a soft, short, vibratory Grade I/II murmur at the LLSB noted on the first day of life. It does not radiate, and there are no other cardiac findings. The infant is feeding well, pink, and gaining weight appropriately. The murmur subsides when mild pressure is applied to the abdomen. By 3 weeks of age, it has disappeared. What was this murmur?

A. A VSD that spontaneously closed

B. A PDA that spontaneously closed

C. A newborn functional murmur — a benign physiologic murmur of the first days of life

D. Peripheral pulmonary stenosis

Question 20

A 5-year-old is referred by their pediatrician for evaluation of a murmur. Which of the following exam findings would be MOST concerning for underlying structural heart disease requiring urgent evaluation?

A. Grade I/II vibratory murmur that decreases when sitting, normal ECG and pulse ox

B. Murmur associated with syncope during exercise, cyanosis at rest, and absent femoral pulses

C. Musical murmur at LLSB loudest when supine that disappears when child sits up

D. Soft murmur noted only during febrile illness that resolves when afebrile

Question 21

A medical student asks you to explain why fetal circulation includes structures that close after birth. In the fetus, the ductus arteriosus connects the pulmonary artery to the aorta. Why is this shunt necessary in utero?

A. To prevent the right ventricle from pumping blood through high-resistance systemic circulation

B. To bypass the non-functional fetal lungs by allowing blood to flow from the pulmonary artery directly to the aorta, avoiding the high-resistance pulmonary vascular bed

C. To allow blood to flow from the left ventricle to the right ventricle

D. To connect the umbilical vein to the inferior vena cava

Question 22

A term neonate has pulse oximetry screening (CCHD screen) performed at 26 hours of life as required by Georgia state law. The result shows SpO2 of 91% in the right hand and 88% in the right foot. What is the significance of this result and what is the next step?

A. Normal result; discharge the infant

B. Failed CCHD screen (both readings below 95%, and differential >3%); requires further evaluation with echocardiography

C. Confirm with repeat in 24 hours and discharge if unchanged

D. This result indicates only peripheral circulatory immaturity; no further workup needed

Question 23

A 9-year-old girl with surgically repaired TOF 3 years ago has a routine dental cleaning scheduled. The dentist asks whether she needs subacute bacterial endocarditis (SBE) prophylaxis. Her most recent cardiology visit noted mild residual pulmonary valve regurgitation at the site of her prior repair. Is SBE prophylaxis indicated?

A. No — surgical repair more than 6 months ago means prophylaxis is never needed

B. Yes — residual valvular regurgitation adjacent to the site of a prosthetic patch or device warrants SBE prophylaxis

C. No — only patients with prosthetic heart valves require prophylaxis

D. Yes — all children with any history of congenital heart disease require lifelong SBE prophylaxis

Question 24

A 28-year-old woman with repaired Tetralogy of Fallot at age 2 presents to your office as a new patient. She reports decreased exercise tolerance over the past year. Which residual complication should be on your differential?

A. Development of new VSD from the original repair

B. Pulmonary stenosis, pulmonary insufficiency (most common), residual VSD, arrhythmias (RBBB), and risk of sudden cardiac death

C. The repair is curative — no follow-up is needed after surgical correction

D. Risk of Eisenmenger physiology — immediate surgical re-repair is indicated

Question 25

A full-term male neonate presents on day 5 of life with cardiovascular collapse — he appeared well in the nursery. Which two diagnoses should be at the TOP of your differential for a full-term neonate presenting in shock on days 3–10 of life as the ductus closes?

A. VSD and ASD

B. Coarctation of the aorta and hypoplastic left heart syndrome — both are duct-dependent for systemic perfusion

C. Tetralogy of Fallot and pulmonary stenosis

D. Transposition of the great arteries and PDA

Question 26

A pediatrician notices a soft heart murmur in a full-term 1-week-old during a routine newborn visit. The infant is pink, feeding well, and gaining weight. What is the most appropriate next step?

A. Immediate referral to the ED for echocardiogram

B. Order an ECG and CXR, and refer to a pediatric cardiologist for evaluation

C. Reassure the family — all newborns have murmurs that resolve

D. Prescribe furosemide empirically for presumed congenital heart disease

Question 27

A medical student asks you to explain the fundamental hemodynamic difference between acyanotic and cyanotic congenital heart disease. Which statement is most accurate?

A. Acyanotic lesions always involve valve stenosis; cyanotic lesions always involve septal defects

B. Acyanotic lesions: left-to-right shunting → increased pulmonary blood flow, no cyanosis. Cyanotic lesions: right-to-left shunting → deoxygenated blood bypasses lungs → cyanosis

C. Acyanotic lesions are always repaired surgically; cyanotic lesions are managed medically

D. Acyanotic lesions present in the first hour of life; cyanotic lesions present in adulthood

Question 28

Which of the following physical exam findings is MOST specific for cyanotic congenital heart disease rather than a primary pulmonary cause of cyanosis?

A. Tachypnea and use of accessory muscles

B. Bilateral rales on auscultation

C. Failure to improve SpO2 with supplemental 100% oxygen (hyperoxia test)

D. Fever and productive cough

Question 29

A parent asks why their 3-month-old with a large VSD needs surgery 'so soon.' The pediatric cardiologist uses the term 'irreversible pulmonary vascular remodeling.' What is the correct explanation for why this occurs?

A. The VSD causes direct damage to the pulmonary valve over time

B. The left-to-right shunt increases pulmonary blood flow, causing vasoactive substance release, vascular remodeling, and progressive obliteration of pulmonary vasculature — eventually becoming fixed and irreversible

C. The increased pulmonary blood flow causes pericardial effusion that compresses the pulmonary vessels

D. The VSD itself directly narrows the pulmonary arteries

Question 30

A 19-year-old woman with known Eisenmenger physiology from an unrepaired large VSD since childhood presents for counseling about pregnancy. What must she be informed?

A. Pregnancy is safe as long as she takes diuretics throughout

B. Surgical repair can now be performed to correct the underlying defect before she becomes pregnant

C. Pregnancy carries extremely high maternal mortality in Eisenmenger physiology and is contraindicated

D. Heart transplantation is required before pregnancy can be considered

Question 31

A pediatrician is listening to a 6-month-old's heart and hears a Grade II/VI systolic ejection murmur heard equally well in both axillae and in the back, with no associated symptoms. The infant is pink, thriving, and has normal oxygen saturation. The murmur gradually disappears by 6 months of age. What is the most likely diagnosis?

A. VSD — refer urgently

B. PDA — start indomethacin

C. Peripheral pulmonary stenosis — a functional murmur of infancy that resolves spontaneously

D. Aortic stenosis — obtain echocardiogram urgently

Question 32

The parents of a 9-year-old boy bring him in after his school nurse noted a murmur on a routine exam. You hear a continuous low-pitched hum in the right infraclavicular area that disappears when the child turns his head to the right or when he lies down. What is this murmur?

A. PDA — refer to cardiology immediately

B. Venous hum — a normal functional murmur caused by turbulent flow in the jugular venous system

C. ASD — refer for echocardiogram

D. Coarctation — measure BP in all four extremities

Question 33

A 2-year-old girl is brought in for evaluation of a murmur. Her mother reports she plays normally but sometimes squats down after running. On exam, you notice mild cyanosis and digital clubbing. SpO2 is 88%. Which diagnosis and which behavior is this child demonstrating?

A. ASD; the child is demonstrating orthopnea

B. VSD; the child is demonstrating compensatory tachypnea

C. Tetralogy of Fallot; squatting increases systemic vascular resistance, decreasing right-to-left shunting and improving oxygenation

D. PDA; the child is demonstrating normal toddler behavior

Question 34

A 3-month-old male with Down syndrome (Trisomy 21) has failure to thrive, tachypnea, and diaphoresis with feeds. Echocardiography confirms a complete atrioventricular septal defect. ECG shows extreme left axis deviation and biventricular hypertrophy. CXR shows four-chamber cardiomegaly. What is the expected time frame and goal of surgical management?

A. Defer surgery until after age 5 to allow spontaneous closure

B. Surgical repair in the FIRST YEAR OF LIFE to prevent pulmonary hypertension

C. Medical management with diuretics alone is sufficient long-term

D. No surgical repair is available — palliative care only

Question 35

A 16-year-old female with Turner syndrome (45,XO) is referred for evaluation of hypertension discovered at her gynecologist's office. BP is 152/94 in both arms but 88/62 in both legs. She has diminished femoral pulses and a systolic murmur in her left axilla and left back. Which associated cardiac finding should also be investigated?

A. Patent ductus arteriosus — check for machinery murmur

B. Bicuspid aortic valve — present in up to 85% of coarctation patients

C. Mitral valve prolapse — most common cardiac anomaly in Turner syndrome

D. Supravalvular aortic stenosis — associated with Williams syndrome, not Turner

Question 36

A 4-year-old boy has been seen multiple times for 'recurrent pneumonias.' Review of records shows bilateral lower lobe infiltrates that clear and recur. He is slightly underweight. On exam, HR is 134, RR is 40, and you hear a Grade IV/VI harsh pansystolic murmur at LLSB with a systolic thrill. CXR shows cardiomegaly and increased pulmonary vascularity. What is the most likely cause of his recurrent infections and the diagnosis?

A. Primary immunodeficiency; refer for immunology workup

B. Cystic fibrosis; sweat chloride test

C. Large VSD causing increased pulmonary blood flow and pulmonary congestion, predisposing to recurrent chest infections

D. Asthma; begin inhaled corticosteroids

Question 37

A premature infant (28 weeks, now 3 weeks old) remains on the ventilator in the NICU. The team notes that vent requirements have increased. You hear a new continuous murmur. CXR shows worsening cardiomegaly and pulmonary edema. Echo confirms a large PDA with left-to-right shunting. Indomethacin is contraindicated because the infant is thrombocytopenic. What is the next treatment option?

A. Ibuprofen (COX inhibitor, similar mechanism to indomethacin, another option for medical PDA closure)

B. Furosemide alone is definitive treatment for PDA in premature infants

C. PGE1 to maintain the ductus

D. Immediate surgical ligation is the only remaining option

Question 38

A 2-day-old female is noted to be mildly cyanotic with SpO2 82%. She is feeding slowly but not in significant distress. On auscultation, a Grade I/II systolic murmur is heard. The pediatrician orders a hyperoxia test — SpO2 improves only minimally (to 86%) despite 100% FiO2. What does this result indicate?

A. Normal finding — premature infants need more oxygen time

B. Primary pulmonary hypertension — begin iNO

C. Cardiac (right-to-left) shunt is likely — the shunt bypasses the lungs, so supplemental O2 cannot reach the shunted blood

D. The pulse oximeter probe was placed incorrectly

Question 39

An adolescent with known repaired ASD presents for follow-up. She is now 18 years old and planning to go to college. She asks if she still needs to follow up with cardiology. Which statement is most accurate?

A. Repaired ASDs never require follow-up after surgical closure

B. She needs follow-up only if she develops symptoms

C. Adults with congenital heart disease require ongoing cardiology follow-up; the number of adults with complex CHD is now 1.4 million in the US and mean age is rising

D. She can transfer to internal medicine and no longer needs cardiology

Question 40

A first-year PA student is asked by an attending to list the four components of Tetralogy of Fallot. Which of the following is the correct complete list?

A. ASD, VSD, PDA, pulmonary stenosis

B. VSD, overriding aorta, pulmonary stenosis, right ventricular hypertrophy

C. VSD, ASD, pulmonary atresia, left ventricular hypertrophy

D. Aortic stenosis, VSD, coarctation, pulmonary stenosis

Question 41

A cardiologist explains to a family that their newborn with TGA needs an 'arterial switch operation' within the first week of life. The parents ask why surgery must happen so soon. What is the primary reason for this timing?

A. The immune system is least likely to reject the procedure in the first week

B. The left ventricle is still capable of sustaining systemic pressures in the first week, before it becomes 'de-trained' by pumping against the low-resistance pulmonary bed

C. Bleeding risk is lowest in the first week of life

D. The ductus arteriosus is easiest to close surgically in the first week

Question 42

A 5-year-old with previously undiagnosed coarctation of the aorta is found to have rib notching on CXR. What causes this finding?

A. Repeated pulmonary infections have eroded the rib cortex

B. Enlarged collateral intercostal arteries bypass the coarctation and erode the inferior border of ribs 4–8

C. Right ventricular hypertrophy causes the ribs to remodel

D. Calcium deposition from pulmonary hypertension

Question 43

Parents of a neonate with hypoplastic left heart syndrome (HLHS) ask about long-term outcomes. Which of the following is the most accurate statement?

A. HLHS is surgically correctable and the child will have a structurally normal heart after repair

B. HLHS has palliative surgical options with 72% survival at 5 years; no corrective surgery exists — cardiac transplantation is the only curative option

C. HLHS is managed medically with prostaglandin E1 long-term

D. HLHS typically resolves spontaneously in the first year of life

Question 44

A 6-month-old male with a known large ASD presents for follow-up. He is mildly symptomatic with decreased exercise tolerance noted by his parents (he tires easily during tummy time). ECG shows right axis deviation. ECHO shows a dilated right atrium and RV. What is the appropriate management?

A. Watchful waiting only — ASDs always resolve spontaneously

B. Indomethacin to promote spontaneous closure

C. Closure via cardiac catheterization or surgical repair for symptomatic patients; watchful waiting for truly asymptomatic patients

D. Diuretics and inotropes are sufficient long-term management

Question 45

An intern asks which cyanotic congenital heart lesion is most commonly FIRST DIAGNOSED in adults as opposed to being caught in infancy or childhood. What is the correct answer?

A. Hypoplastic left heart syndrome

B. Transposition of the great arteries

C. Tetralogy of Fallot — the most common cyanotic congenital anomaly seen in adults

D. Truncus arteriosus

Question 46

A 4-day-old male infant has a continuous Grade III/VI 'machinery' murmur heard below the left clavicle. Echocardiography confirms a large PDA with significant left-to-right shunting. He has no contraindications to NSAIDs. What is the mechanism by which indomethacin promotes ductal closure?

A. Indomethacin blocks calcium channels in the ductal smooth muscle

B. Indomethacin inhibits prostaglandin synthesis (COX inhibitor), reducing prostaglandin E2 and E1 levels — prostaglandins keep the ductus open

C. Indomethacin directly stimulates ductal smooth muscle to contract

D. Indomethacin increases oxygen tension, which is the primary trigger for ductal closure

Question 47

A 10-year-old is seen for a sports physical. He is completely asymptomatic. On auscultation you hear a Grade III/IV harsh systolic ejection murmur at the right upper sternal border (aortic area) that radiates to the carotids. There is no change with positional maneuvers. Which finding on this exam would MOST indicate a pathologic rather than functional murmur?

A. Grade III intensity

B. Systolic timing

C. Right upper sternal border location with carotid radiation, associated with a systolic click or thrill

D. Disappearance with deep inspiration

Question 48

A 2-month-old infant is admitted with respiratory distress, poor feeding, and HR of 180. A large VSD was identified on echocardiogram. The attending orders furosemide and explains they will also begin feeding the baby in an upright position. Why is positioning important in VSD management?

A. Upright positioning reduces cardiac output and lowers heart rate

B. Upright positioning reduces gastroesophageal reflux risk only

C. Upright positioning reduces the effort of breathing against gravity-dependent pulmonary edema, making feeds less metabolically demanding for a baby in heart failure

D. Upright positioning increases systemic vascular resistance and reduces left-to-right shunting

Question 49

Which of the following correctly matches a congenital heart lesion with its characteristic CXR finding?

A. VSD — 'egg on a string'; ASD — rib notching

B. Tetralogy of Fallot — 'boot-shaped heart' with decreased pulmonary vascularity; TGA — 'egg on a string' with increased pulmonary markings; coarctation — 'figure of 3' sign with rib notching

C. PDA — 'boot-shaped heart'; TOF — 'egg on a string'

D. Coarctation — cardiomegaly only; ASD — 'figure of 3' sign

Question 50

A PA student is asked to counsel a family about the incidence and genetic causes of congenital heart disease. Which statement is most accurate based on the lecture content?

A. CHD affects 1 per 1000 live births; most cases have a purely genetic cause

B. CHD affects 8 per 1000 live births (40,000 diagnoses per year); 90% are due to multifactorial genetics and 5–10% to primary genetic factors

C. CHD affects 1 in 100 live births; most are due to chromosomal abnormalities alone

D. CHD affects 8 per 1000 live births; 100% are due to identifiable single-gene mutations

PART II — ANSWER KEY WITH CLINICAL RATIONALES

Q1.  Answer: B

Large VSDs (6–10 mm) typically present around 3 months of age with signs of congestive heart failure: tachypnea, diaphoresis with feeds, poor weight gain, and recurrent chest infections. The harsh pansystolic murmur at LLSB is classic. The most critical long-term complication to prevent is pulmonary hypertension from the long-standing left-to-right shunt. If pulmonary vascular resistance becomes fixed and exceeds systemic resistance, the shunt reverses (Eisenmenger physiology) and the defect becomes inoperable. Surgical repair is performed in infancy or before age 2 to prevent this.

Q2.  Answer: C

Small VSDs (<3mm) account for 80–85% of all VSDs. They are often asymptomatic, and the murmur may be noted at 4–10 days on routine exam as pulmonary vascular resistance falls. Nearly all small VSDs close spontaneously without intervention. Watchful waiting with periodic follow-up is appropriate. Indomethacin is used for PDA closure, not VSDs. Surgical repair and diuretics are reserved for large, symptomatic VSDs with signs of heart failure.

Q3.  Answer: B

The primary goal of timely VSD repair is prevention of pulmonary hypertension. The chronic left-to-right shunt increases pulmonary blood flow, causing vasoactive mediator release, vascular remodeling, and progressive pulmonary vascular obstruction. Once pulmonary vascular resistance becomes fixed and irreversible (Eisenmenger physiology — right-to-left shunt), surgical repair is no longer possible. Surgical mortality for VSD closure is <2%. Endocarditis prophylaxis is required for 6 months after repair.

Q4.  Answer: B

ASD presents with a wide, fixed split S2 — this is pathognomonic. The split is fixed (does not vary with respiration) because the right ventricle always has excess volume from the left-to-right shunt at the atrial level, equalizing RV filling regardless of respiratory phase. The murmur is a systolic ejection murmur in the pulmonic area from increased flow across the pulmonary valve (not from flow through the ASD itself). ECG shows right axis deviation; ECHO shows dilated RA and RV. ASD accounts for 30–40% of congenital heart disease in adults and often goes undiagnosed until adulthood.

Q5.  Answer: C

Common atrioventricular septal defect (AVSD, also called common AV canal defect) is strongly associated with Trisomy 21 (Down syndrome). The AV septum fails to form properly, creating both atrial and ventricular level shunts plus abnormal AV valve formation. Signs include FTT, tachypnea, and diaphoresis with feeds. The ECG hallmark is extreme left axis deviation. CXR shows four-chamber enlargement. Pulmonary hypertension develops over time due to the combined ASD + VSD shunting. Surgical repair is required in the first year of life.

Q6.  Answer: C

Patent ductus arteriosus (PDA): the ductus arteriosus should close within 1–5 days of birth (up to 10 days). Incidence is higher in premature neonates. The classic murmur is a continuous 'machinery-like' murmur heard below the LEFT CLAVICLE at the left 2nd ICS, beginning just after S1, peaking at S2, and decrescendoing into diastole. Widened pulse pressure and bounding pulses result from aortic runoff into the pulmonary artery during diastole. First-line medical treatment in premature infants is INDOMETHACIN (inhibits prostaglandin synthesis, promoting ductal closure). Surgical ligation or coil closure by 1 year if medical management fails.

Q7.  Answer: C

PDA is associated with a NARROWLY SPLIT S2 — the increased left ventricular stroke volume and aortic runoff increase the aortic component of S2 and narrow the split. The murmur is continuous (systolic AND diastolic), beginning after S1, peaking at S2, and decrescendoing into diastole. This distinguishes PDA from VSD (pansystolic only). Treatment in a full-term infant who fails medical management is surgical ligation or catheter-based coil placement by 1 year of age.

Q8.  Answer: B

Coarctation of the aorta: 60% of patients present in later childhood or adolescence with insidious hypertension in the upper extremities and diminished/absent femoral pulses (pulse discrepancy between UE and LE is the hallmark). CXR shows rib notching from collateral intercostal arteries and the 'figure of 3' sign from the coarctation and dilated vessels. In FEMALE patients, Turner syndrome (45,XO) must be ruled out — coarctation is a common cardiac manifestation. Male:Female ratio is 3:1. Up to 85% have an associated bicuspid aortic valve. Treatment: balloon angioplasty or surgical repair before age 5.

Q9.  Answer: B

Neonatal coarctation presents on days 4–10 as the ductus arteriosus closes. The infant appears well at birth but deteriorates rapidly when ductal closure occurs, eliminating the bypass flow around the obstruction. This produces cardiogenic shock. IMMEDIATE TREATMENT: PROSTAGLANDIN E1 (PGE1) infusion to reopen the ductus and restore systemic perfusion. This is a temporizing measure before surgical correction. 40% of coarctation patients present this way in infancy. Without treatment, mortality is high.

Q10.  Answer: C

Tetralogy of Fallot (TOF) is the MOST COMMON cyanotic congenital malformation (10% of all CHD). The 4 components are: pulmonic stenosis, VSD, overriding aorta, and right ventricular hypertrophy. Classic findings: infants are often PINK at birth, then develop progressive cyanosis over months as pulmonary stenosis worsens. CXR shows 'boot-shaped' heart (elevated cardiac apex from RVH) with DECREASED pulmonary vascularity (distinguishes from most other CHD which increases pulmonary flow). Digital clubbing and decreased exercise tolerance develop over time.

Q11.  Answer: B

Hypercyanotic 'Tet' spells are medical emergencies. Crying or exercise triggers infundibular spasm → increased right-to-left shunting → profound cyanosis and hypoxia → altered consciousness. FIRST STEP: CALM THE CHILD + KNEE-TO-CHEST POSITION (increases systemic vascular resistance, reducing right-to-left shunt) + supplemental oxygen. Pharmacologic options if non-invasive measures fail: morphine (decreases infundibular spasm), ketamine (increases SVR), volume expansion. Diuretics and inotropes are CONTRAINDICATED — they worsen tet spells by decreasing preload and increasing heart rate. Surgical repair or palliation is the definitive treatment.

Q12.  Answer: C

TOF is NOT managed medically long-term. Diuretics decrease preload and inotropes increase infundibular spasm — both worsen hypercyanotic tet spells. Palliative surgery (Blalock-Taussig shunt — creates a conduit between the subclavian artery and pulmonary artery to increase pulmonary blood flow) may be done first. Complete repair involves patch closure of the VSD and enlargement of the pulmonary outflow tract, typically performed between birth and 2 years of age. Survival at 10 years is 90–95% after corrective surgery. Without surgery: 50% mortality in first few years.

Q13.  Answer: B

Transposition of the Great Arteries (TGA) is the MOST COMMON cyanotic CHD presenting in the NEONATAL PERIOD. The aorta arises from the RV and the pulmonary artery from the LV — two parallel, non-communicating circuits incompatible with life. Key features: severe cyanosis from birth, NO respiratory distress (distinguishes from respiratory causes of cyanosis), cyanosis persists despite 100% O2. CXR: 'egg on a string' (narrow mediastinum). IMMEDIATE TREATMENT: PGE1 to keep the ductus open. Balloon atrial septostomy for mixing. Definitive: arterial switch operation at 4–7 days of life (95% survival).

Q14.  Answer: C

In TGA, the pulmonary and systemic circulations are in parallel rather than in series — incompatible with life postnatally. During fetal life, survival is possible because the foramen ovale (FO) and ductus arteriosus (DA) allow mixing between the right-sided (oxygenated in utero) and left-sided circulations. After birth, as FO and DA close, mixing becomes inadequate and severe hypoxemia ensues. This is why PGE1 (to keep the ductus open) and balloon atrial septostomy (to create/enlarge an atrial level communication) are critical temporizing measures before arterial switch surgery.

Q15.  Answer: C

Hypoplastic left heart syndrome (HLHS): the left ventricle, mitral valve, and aortic valve are severely underdeveloped. Systemic circulation is entirely duct-dependent — the right ventricle pumps through the ductus arteriosus to reach the descending aorta. When the ductus closes on day 3–7, the infant collapses rapidly with shock, acidosis, and cyanosis. IMMEDIATE LIFE-SAVING TREATMENT: PGE1 to reopen the ductus. HLHS is often diagnosed prenatally with fetal echocardiography. No corrective surgery is available — only complex palliative surgery (72% survival at 5 years) or cardiac transplantation.

Q16.  Answer: B

Eisenmenger physiology: when long-standing left-to-right shunting (from VSD, ASD, or PDA) causes progressive pulmonary vascular remodeling until pulmonary vascular resistance exceeds systemic resistance, the shunt REVERSES to right-to-left, producing cyanosis. At this stage, SURGICAL REPAIR IS NO LONGER POSSIBLE (closing the defect would cause acute right heart failure). Management: palliative — pulmonary vasodilators (sildenafil, bosentan), oxygen, phlebotomy for polycythemia. This is why early surgical repair of large VSDs before age 2 is critical.

Q17.  Answer: B

In ASD, blood flows from left to right atrium because left atrial pressure exceeds right atrial pressure. This pressure gradient exists because pulmonary vascular resistance is much lower than systemic vascular resistance (approximately 1/8 of systemic). Left atrial pressure is higher because the left ventricle works against higher systemic resistance. The increased flow through the tricuspid and pulmonary valves from the L→R shunt is what generates the systolic ejection murmur heard in the pulmonary area and the wide fixed split S2 from the volume-overloaded right ventricle.

Q18.  Answer: C

Still's murmur is the most common functional (innocent) murmur in children. Key features: musical or vibratory quality, grade I–III, early to midsystolic, heard best at LLSB and apex, DECREASES when sitting or with inspiration (postural change is a hallmark of innocent murmurs), LOUDEST when supine. Cause: vibrations from normal left ventricular flow. Ages 2–8 are most common. No cardiac symptoms, normal ECG, normal CXR, and normal pulse oximetry confirm the benign nature. Echocardiogram is not routinely needed for classic Still's murmur.

Q19.  Answer: C

Newborn functional murmur: a benign physiologic murmur heard in the first few days of life. It is soft, short, and vibratory (Grade 1–2), heard at LLSB without radiation, and often subsides with mild abdominal pressure. It disappears by 2–3 weeks of age. This is distinct from peripheral pulmonary stenosis (another neonatal murmur heard at the axillae and back that resolves by 6 months) and from pathologic causes. An infant who is pink, feeding well, and growing normally with this murmur pattern does not require urgent cardiology referral.

Q20.  Answer: B

RED FLAGS suggesting structural heart disease in a child with a murmur: syncope during exercise, cyanosis, absent femoral pulses (suggesting coarctation), palpitations, dyspnea on exertion, and family history of sudden cardiac death. Any of these warrant urgent evaluation including ECG, CXR, and echocardiogram — referral to ED if the patient is in extremis. Innocent murmurs: vibratory, grade I–III, systolic only, decrease with sitting/inspiration, no associated symptoms, normal vital signs, normal pulse oximetry. A murmur that worsens with fever or exercise may simply be physiologic increased cardiac output.

Q21.  Answer: B

In fetal circulation, the lungs are non-functional and have high vascular resistance. The ductus arteriosus allows blood to bypass the pulmonary vasculature by connecting the pulmonary artery directly to the aorta, letting blood reach the systemic circulation without passing through the lungs. After birth, the lungs expand, pulmonary vascular resistance drops dramatically, and the ductus closes within 1–5 days (stimulated by increased O2 tension and decreased prostaglandins). The ductus venosus connects the umbilical vein to the IVC (bypasses liver). The foramen ovale allows right-to-left atrial mixing.

Q22.  Answer: B

Georgia enacted CCHD screening legislation in May 2014, requiring pulse oximetry screening at ≥24 hours of life. A FAILED screen triggers further workup including echocardiography. Criteria for a failed screen: SpO2 <90% in either site, or SpO2 <95% in both sites on three separate occasions, or >3% absolute difference between the right hand (pre-ductal) and foot (post-ductal) readings on three separate occasions. This patient's 91% right hand and 88% foot with a 3% differential is a failed screen and cannot be dismissed as peripheral immaturity. CCHD screen results must be recorded in the birth chart and reported to the Department of Public Health.

Q23.  Answer: B

SBE prophylaxis is indicated for highest-risk patients including: prosthetic valves, prior history of infective endocarditis, valve regurgitation in a transplanted heart, unrepaired cyanotic CHD, and REPAIRED CHD with residual shunts or valvular regurgitation adjacent to the site of a prosthetic patch or device. This patient has residual pulmonary regurgitation at the repair site — this qualifies for prophylaxis. Note: repaired CHD defects without residual defects MORE THAN 6 months after surgery do NOT require prophylaxis (endothelialization of the patch is complete). Prophylaxis is given before dental procedures causing bacteremia.

Q24.  Answer: B

Residual effects after TOF repair include: pulmonary stenosis (residual obstruction), pulmonary INSUFFICIENCY (most common — from enlargement of the outflow tract during repair), residual VSD, arrhythmias (RBBB is classic on ECG, which can cause sudden cardiac death), and RV dilatation from chronic pulmonary regurgitation. TOF is the most common cyanotic congenital anomaly in adults. Indications for re-referral: decreased exercise tolerance, angina, evidence of heart failure, arrhythmia, syncope, and increased RV pressure. Lifelong cardiology follow-up is mandatory. Survival at 10 years = 90–95%; at 30 years = ~85%.

Q25.  Answer: B

The classic 'duct-dependent' lesions presenting in the first week of life as the DA closes: (1) COARCTATION OF THE AORTA — severe cases depend on the ductus to bypass the obstruction. (2) HYPOPLASTIC LEFT HEART SYNDROME — entirely duct-dependent for systemic circulation. Both present on days 3–10 with cardiovascular collapse as the ductus closes. BOTH require PGE1 as immediate treatment to reopen the ductus. TGA presents with cyanosis within hours but typically without shock. VSD and ASD present weeks to months later as pulmonary vascular resistance falls.

Q26.  Answer: B

A murmur in a newborn requires investigation even if the infant appears well. The appropriate initial workup in the office includes ECG and CXR. These can help identify chamber hypertrophy, cardiomegaly, and pulmonary vascular changes. Echocardiogram (preferably at a pediatric center) is the definitive study. Cardiac catheterization and MRI are at the discretion of cardiology. The family should NOT be dismissed with reassurance alone. Refer to the ED only if the patient is in extremis (cyanosis, cardiovascular collapse, severe respiratory distress).

Q27.  Answer: B

Acyanotic CHD: left-to-right shunts move oxygenated blood back into the pulmonary circulation → excess pulmonary blood flow → no cyanosis (blood reaching the periphery is oxygenated). Over time, increased pulmonary flow can cause pulmonary hypertension and eventually Eisenmenger physiology with shunt reversal. Cyanotic CHD: right-to-left shunts send deoxygenated blood directly into the systemic circulation → cyanosis, clubbing, polycythemia. The 'T's of cyanotic CHD: Tetralogy of Fallot, Transposition, Truncus, TAPVR, Tricuspid atresia.

Q28.  Answer: C

The hyperoxia test (also called the nitrogen washout test) is used to differentiate cardiac from pulmonary causes of cyanosis. Administer 100% O2 for 10 minutes. PULMONARY cause: SpO2 rises significantly (oxygen can enter the alveoli and correct V/Q mismatch). CARDIAC cause (right-to-left shunt): SpO2 does NOT improve significantly with 100% O2, because deoxygenated blood is bypassing the lungs entirely and entering the systemic circulation directly. This is especially relevant in TGA (severely cyanotic despite 100% O2). Tachypnea, rales, and fever suggest primary pulmonary disease.

Q29.  Answer: B

Large left-to-right shunts (VSD, ASD, PDA) increase pulmonary blood flow. This triggers release of vasoactive substances from the pulmonary endothelium, causing vascular remodeling and progressive obliteration of the pulmonary vascular bed. Pulmonary vascular resistance rises progressively. Once it reaches systemic resistance, the shunt reverses (Eisenmenger physiology) and becomes fixed and irreversible. At that point surgical repair is no longer feasible (closing the VSD would eliminate the right ventricle's only outlet). This is why large VSDs require repair before age 2.

Q30.  Answer: C

Eisenmenger physiology with pregnancy carries maternal mortality of up to 30–50%. The systemic vasodilation of pregnancy reduces systemic vascular resistance, worsening the right-to-left shunt and causing dangerous hypoxemia. Surgical repair is NO LONGER POSSIBLE once Eisenmenger physiology is established — closing the VSD would cause fatal acute right heart failure. Pregnancy is CONTRAINDICATED. Patients should be counseled extensively about contraception. Pulmonary vasodilators (sildenafil, bosentan) can help symptoms but do not reverse the pathology.

Q31.  Answer: C

Peripheral pulmonary stenosis (PPS) is a normal physiologic murmur of early infancy (first weeks to 6 months). It is caused by relative narrowing at the junction of the main and branch pulmonary arteries — the branch arteries are small at birth relative to the main pulmonary artery. Features: Grade I–II systolic ejection murmur heard equally well in the AXILLAE and BACK (distinguishing feature from other functional murmurs) as well as the anterior chest. It resolves spontaneously by 6 months as the arteries grow. No treatment is required.

Q32.  Answer: B

Venous hum is a normal, functional, continuous murmur caused by turbulent flow in the jugular venous system. It is heard in the right infraclavicular area (or neck), is continuous (systolic AND diastolic), and is distinguished from PDA by: (1) it disappears when the child LIES DOWN (increased venous return equalizes pressure), (2) it disappears when the child turns the head to the RIGHT (compresses the jugular vein), and (3) it can be made to disappear with gentle compression of the neck veins. No treatment is required. Venous hum is most common in ages 3–8.

Q33.  Answer: C

Squatting is characteristic of Tetralogy of Fallot. Squatting compresses the femoral arteries and increases systemic vascular resistance. This increases left-sided pressures and reduces the right-to-left shunt across the VSD, improving pulmonary blood flow and oxygenation temporarily. This is the compensatory behavior children with TOF use instinctively. It is the physiology exploited therapeutically in the 'knee-to-chest' position used during hypercyanotic tet spells. Digital clubbing and cyanosis at SpO2 88% confirm significant right-to-left shunting.

Q34.  Answer: B

AVSD (complete AV canal defect) has a strong association with Trisomy 21. Due to the combined ASD + VSD level shunting, there is a very high risk of early pulmonary hypertension — children with Down syndrome are at particularly high risk for early pulmonary vascular changes. Surgical repair in the FIRST YEAR OF LIFE is required to prevent irreversible pulmonary hypertension. Medical management with diuretics may help with symptoms temporarily, but is not definitive. Extreme left axis deviation on ECG is the hallmark ECG finding of AVSD (unlike most other CHD which shows right axis deviation or right ventricular hypertrophy).

Q35.  Answer: B

Coarctation of the aorta is the most common cardiac finding in Turner syndrome (45,XO). Up to 85% of patients with coarctation also have a BICUSPID AORTIC VALVE, which requires separate evaluation and long-term monitoring. Rib notching on CXR (from collateral intercostal arteries) and the 'figure of 3' sign are radiographic clues. The upper-lower extremity BP discrepancy and diminished femoral pulses are the clinical hallmarks. Aortic stent placement is an option for adults; balloon angioplasty or surgery is performed in children before age 5. Re-coarctation rate is 10–15%.

Q36.  Answer: C

Large VSDs cause dramatically increased pulmonary blood flow, leading to pulmonary congestion and predisposition to recurrent lower respiratory tract infections. This is one of the hallmark features of large VSD: recurrent chest infections + tachypnea + poor weight gain + harsh pansystolic murmur at LLSB with thrill + cardiomegaly on CXR. The child's failure to thrive, tachycardia, and tachypnea further support heart failure from large VSD. Surgical repair is indicated and should be performed before age 2 to prevent pulmonary hypertension. Recurrent pneumonias resolving after cardiac repair confirms the etiology.

Q37.  Answer: A

In premature infants with a hemodynamically significant PDA, medical closure is attempted first. INDOMETHACIN and IBUPROFEN (both COX inhibitors that reduce prostaglandin synthesis) are the pharmacologic options. If indomethacin is contraindicated (thrombocytopenia, renal insufficiency, GI bleeding), ibuprofen is the alternative. If both fail or are contraindicated, surgical ligation or transcatheter coil/device closure are performed. PGE1 is the OPPOSITE — it OPENS the ductus (used for duct-dependent lesions). Furosemide alone manages symptoms but does not close the ductus.

Q38.  Answer: C

The hyperoxia test: if SpO2 fails to improve significantly with 100% O2, it indicates a CARDIAC cause (right-to-left shunt) rather than a pulmonary cause. In right-to-left shunts (cyanotic CHD), deoxygenated blood bypasses the lungs and enters the systemic circulation directly — supplemental O2 in the alveoli cannot reach blood that never passes through the alveoli. Pulmonary causes of cyanosis (V/Q mismatch, RDS) respond to O2 because the blood does pass through the lungs. This infant requires urgent echocardiography to define the cardiac anatomy.

Q39.  Answer: C

The number of adults living with complex congenital heart disease has grown dramatically — approximately 1.4 million adults in the US, exceeding the number of children with CHD. Medical complications in adults with CHD include: pulmonary hypertension, hypoxemia, hyperviscosity/erythrocytosis/iron deficiency, headaches, stroke, gout, and hypertrophic osteoarthropathy. Exercise testing before athletic participation is required for many patients. Lifelong cardiology follow-up at a center specializing in adult congenital heart disease (ACHD) is the standard of care.

Q40.  Answer: B

Tetralogy of Fallot — 4 components (mnemonic: PROVE): Pulmonic Stenosis, Right Ventricular Hypertrophy, Overriding Aorta, VSD. The pulmonary stenosis (right ventricular outflow tract obstruction) is the primary determinant of severity — the degree of obstruction determines how much blood bypasses the lungs and how cyanotic the infant becomes. The overriding aorta sits directly above the VSD and receives blood from both ventricles. RVH is a consequence of the pulmonary stenosis. Together these four components produce the 'boot-shaped' heart on CXR with decreased pulmonary vascularity.

Q41.  Answer: B

In TGA, the left ventricle pumps against the low-resistance pulmonary bed (because the pulmonary artery arises from the LV). After a few weeks, the LV loses its muscular mass ('de-trains') because it only needs to generate low pressure. The arterial switch must be performed at 4–7 days of life — before the LV loses its ability to support the systemic circulation. If delayed beyond 2–3 weeks, the LV may be too underpowered to take over systemic circulation after the switch. This is why TGA requires urgent diagnosis and immediate stabilization with PGE1 + balloon atrial septostomy + prompt surgical planning.

Q42.  Answer: B

Rib notching in coarctation of the aorta is caused by enlarged COLLATERAL INTERCOSTAL ARTERIES. Blood bypasses the obstructed aortic segment by flowing through collateral vessels (subclavian → internal mammary → intercostal arteries → descending aorta). These intercostal arteries enlarge markedly over time and erode the INFERIOR BORDER of ribs 4–8 (sparing ribs 1–3 which arise above the collateral network). It typically takes several years to develop, which is why it is seen in older children and adolescents with undiagnosed coarctation but NOT in neonates presenting in shock. The 'figure of 3' sign on CXR is from the dilated aorta above and below the coarctation.

Q43.  Answer: B

HLHS has no CORRECTIVE surgery — the left ventricle cannot be reconstructed. PALLIATIVE surgery (Norwood procedure series — three operations over the first 3 years of life) allows the right ventricle to take over as the systemic pump. 5-year survival with palliation is approximately 72%. Cardiac transplantation is the only truly corrective option but is limited by donor availability and carries its own long-term complications (rejection, immunosuppression). PGE1 is only used acutely to maintain ductal patency — it is not a long-term medication. HLHS is often diagnosed prenatally on fetal echocardiography.

Q44.  Answer: C

ASD management depends on symptoms and size. SYMPTOMATIC patients require closure — this can be done via cardiac catheterization (device closure) or surgical repair. ASYMPTOMATIC patients can be observed. Unlike most VSDs, ASDs rarely close spontaneously in symptomatic patients with significant shunts. This infant has symptoms (fatigability), RV dilation on ECHO, and RAD on ECG — these are indications for repair. ASD accounts for 30–40% of congenital heart disease first diagnosed in ADULTS — many are missed in childhood due to subtlety of symptoms. The wide fixed split S2 remains the hallmark auscultatory finding.

Q45.  Answer: C

Tetralogy of Fallot is the most common cyanotic congenital malformation that is seen in adults. TGA is diagnosed within hours of birth (severely cyanotic neonate). HLHS is diagnosed within days (shock when ductus closes). Truncus arteriosus presents early in infancy. TOF, with its variable degree of pulmonic stenosis, can present anywhere from immediate cyanosis to very mild cyanosis discovered later in childhood or even adulthood. With improved surgical outcomes (10-year survival 90–95%, 30-year survival ~85%), the population of adults living with repaired TOF is substantial. It is the most common cyanotic CHD seen in adult congenital heart disease clinics.

Q46.  Answer: B

The ductus arteriosus is maintained open in utero by PROSTAGLANDINS (PGE1 and PGE2) produced by the placenta and ductus itself. After birth, prostaglandin levels fall and oxygen tension rises — both stimulate ductal closure. INDOMETHACIN (and ibuprofen) inhibit cyclooxygenase (COX), reducing prostaglandin synthesis and promoting ductal constriction and closure. This is why PGE1 is given to OPEN the ductus in duct-dependent lesions (TOF, coarctation, HLHS, TGA), and why indomethacin is given to CLOSE an unwanted PDA.

Q47.  Answer: C

Red flags distinguishing PATHOLOGIC from innocent murmurs: (1) DIASTOLIC component (all diastolic murmurs are pathologic), (2) Grade IV or higher with a THRILL, (3) Harsh quality, (4) Location at RIGHT UPPER STERNAL BORDER (aortic stenosis), (5) RADIATION (to carotids = aortic stenosis, to axillae and back = coarctation or pulmonary stenosis), (6) Associated symptoms (syncope, chest pain, dyspnea), (7) Does NOT change with position. Innocent murmurs are always systolic, grade I–III, decrease with sitting/inspiration, have no radiation, and are associated with no symptoms. Right upper sternal border location with carotid radiation and a thrill suggests aortic stenosis.

Q48.  Answer: C

Medical management of large VSD includes: inotropes, diuretics (furosemide — to reduce volume overload and pulmonary edema), and feeding modifications. Feeding in an UPRIGHT POSITION is recommended because: (1) it reduces the work of breathing against gravity-dependent pulmonary edema, (2) reduces aspiration risk, and (3) makes the metabolically demanding process of feeding less exhausting for an infant in heart failure. Feeds are often given via nasogastric tube in severe cases because the energy expenditure of sucking may exceed the caloric intake. Goal caloric density may be increased. Surgical repair is the definitive treatment.

Q49.  Answer: B

High-yield CXR findings in CHD: (1) TOF = 'BOOT-SHAPED HEART' (elevated cardiac apex from RVH) with DECREASED pulmonary vascularity (from pulmonary stenosis reducing pulmonary flow). (2) TGA = 'EGG ON A STRING' (narrow superior mediastinum from the parallel great vessels) with INCREASED pulmonary markings. (3) Coarctation = 'FIGURE OF 3' sign (from the dilated aortic knob, coarctation indentation, and post-stenotic dilation) + RIB NOTCHING (collateral vessels). (4) VSD/ASD/PDA = cardiomegaly + increased pulmonary vascularity (from left-to-right shunting increasing pulmonary flow).

Q50.  Answer: B

CHD epidemiology from the lecture: incidence is 8 per 1000 live births, accounting for approximately 40,000 diagnoses per year. CAUSES: 90% of lesions are due to MULTIFACTORIAL genetics (combination of polygenic susceptibility + environmental factors). Only 5–10% are due to primary genetic factors (chromosomal abnormalities like Trisomy 21/AVSD, Turner/coarctation, DiGeorge/22q11 deletion/TOF, or single-gene mutations). This multifactorial nature makes precise genetic counseling challenging. CHD is the most common form of congenital malformation in huma