Congenital Heart Disease USMLE Step 1 Practice Question
A 6-year-old boy with Down syndrome presents to the clinic with progressive dyspnea on exertion over the past 6 months. His mother reports he can no longer keep up with peers during play. Vital signs: HR 115 bpm, RR 30, BP 92/58, SpO2 91% on room air. Physical examination reveals a hyperdynamic precordium with prominent right ventricular heave, single loud S2 with accentuated pulmonary component, and a holosystolic murmur best heard at the left lower sternal border. No cyanosis is noted. Chest X-ray shows increased pulmonary vascular markings, pulmonary artery prominence, and right atrial enlargement. Which of the following is the most likely diagnosis?
Answer choices
- AAtrioventricular septal defect with early pulmonary hypertensionCorrect answer
- BTetralogy of Fallot with progressive right ventricular outflow tract obstruction
- CAtrioventricular septal defect with established Eisenmenger syndrome
- DPartial anomalous pulmonary venous return to the superior vena cava
- EPatent foramen ovale with secundum-type atrial septal defect
- FHypoplastic left heart syndrome with atrial septal communication
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