NBE Pediatric Echocardiography 3 — Questions and Answers
Question 1: A 2-year-old child with Down syndrome has an atrioventricular septal defect (AVSD). Which component is essential for classifying it as a complete AVSD?
- Presence of a common AV valve with primum ASD and inlet VSD (Correct answer)
- Presence of separate mitral and tricuspid valves with a large secundum ASD
- Presence of a muscular VSD only
- Absence of the coronary sinus
Correct answer: Presence of a common AV valve with primum ASD and inlet VSD
Complete AVSD is defined by a common AV valve orifice combined with a primum ASD and an inlet VSD, all resulting from deficiency of the atrioventricular septum.
Question 2: In pediatric echocardiography, which formula is used to estimate right ventricular systolic pressure (RVSP) from tricuspid regurgitation?
- RVSP = 4V² + RAP, where V is the TR peak velocity (Correct answer)
- RVSP = 4V² − RAP, where V is the TR peak velocity
- RVSP = 2V + RAP, where V is the TR mean velocity
- RVSP = V² + RAP, where V is the TR peak velocity
Correct answer: RVSP = 4V² + RAP, where V is the TR peak velocity
Using the simplified Bernoulli equation, RVSP = 4 × (peak TR velocity)² + estimated right atrial pressure.
Question 3: Which echocardiographic finding in a neonate is most characteristic of critical pulmonary stenosis with intact ventricular septum?
- Severely thickened, doming pulmonary valve with high-velocity antegrade flow and right-to-left ductal shunting (Correct answer)
- Dilated pulmonary artery with absent valve leaflets
- Large VSD with bidirectional shunting
- Retrograde aortic arch flow
Correct answer: Severely thickened, doming pulmonary valve with high-velocity antegrade flow and right-to-left ductal shunting
Critical pulmonary stenosis presents with a severely thickened doming pulmonary valve, high antegrade velocity, right ventricular hypertrophy, and right-to-left shunting at the ductus arteriosus due to ductal dependency.
Question 4: In a child with coarctation of the aorta, which Doppler pattern in the descending aorta is most diagnostic?
- High-velocity systolic flow with a normal diastolic runoff
- High-velocity flow with diastolic runoff (sawtooth pattern) and increased velocity proximal to the coarctation
- Low-velocity blunted systolic flow with diastolic reversal
- High-velocity flow with prolonged pressure half-time and diastolic tail (Correct answer)
Correct answer: High-velocity flow with prolonged pressure half-time and diastolic tail
Coarctation produces a high-velocity jet at the narrowing with a diastolic tail (prolonged pressure half-time and continued forward diastolic flow) due to persistent pressure gradient throughout the cardiac cycle.
Question 5: A newborn with cyanosis has a chest X-ray showing a 'snowman' or 'figure-of-8' heart silhouette. Which echocardiographic finding confirms the likely diagnosis?
- Pulmonary veins draining into a vertical vein connecting to the innominate vein and SVC (supracardiac TAPVR) (Correct answer)
- Large ostium secundum ASD with left-to-right shunting
- Aorta anterior to the pulmonary artery
- Hypoplastic right ventricle with tricuspid atresia
Correct answer: Pulmonary veins draining into a vertical vein connecting to the innominate vein and SVC (supracardiac TAPVR)
The 'snowman' silhouette on chest X-ray is classic for supracardiac total anomalous pulmonary venous return (TAPVR), where pulmonary veins drain via a vertical vein to the innominate vein and SVC.
Question 6: Which structure separates the left atrium from the right atrium and, when absent or deficient, results in a secundum atrial septal defect?
- Septum primum
- Septum secundum (fossa ovalis region) (Correct answer)
- Atrioventricular septum
- Sinus venosus septum
Correct answer: Septum secundum (fossa ovalis region)
Secundum ASDs occur due to deficiency of the septum secundum (or excessive resorption of septum primum) in the region of the fossa ovalis.
Question 7: In a 10-year-old child, the echocardiogram shows a dilated coronary sinus. Which condition should be suspected first?
- Total anomalous pulmonary venous return
- Persistent left superior vena cava draining into the coronary sinus (Correct answer)
- Coronary artery fistula
- Pulmonary arteriovenous malformation
Correct answer: Persistent left superior vena cava draining into the coronary sinus
A dilated coronary sinus in a child most commonly indicates a persistent left superior vena cava (PLSVC) draining into the coronary sinus, confirmed by injection of agitated saline into the left arm.
NBE Pediatric Echocardiography 3
A 2-year-old child with Down syndrome has an atrioventricular septal defect (AVSD).
Which component is essential for classifying it as a complete AVSD?