Congenital Heart Disease USMLE Step 1 Practice Question
A 4-year-old boy with Down syndrome presents to clinic with progressive exertional dyspnea and fatigue over the past 6 months. His mother reports he tires easily compared to his siblings and has difficulty keeping up during play. Physical examination reveals a systolic murmur best heard at the left lower sternal border, a fixed split S2, and mild hepatomegaly. Chest X-ray demonstrates cardiomegaly with increased pulmonary vascular markings. Echocardiography shows an ostium primum atrial septal defect (ASD) with a left-to-right shunt and signs of pulmonary overcirculation. Which of the following complications is this patient at highest risk of developing if the defect is not closed?
Answer choices
- AMitral stenosis from rheumatic heart disease
- BAcute bacterial endocarditis affecting the mitral valve
- CSpontaneous closure of the defect leading to normalization of pulmonary pressures
- DProgressive pulmonary hypertension with eventual reversal of shunt flow (Eisenmenger syndrome)Correct answer
- EAortic root dilation and acute aortic dissection
- FDextrocardia with situs inversus totalis
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