Congenital Heart Disease USMLE Step 1 Practice Question
A 2-day-old male infant presents to the neonatal intensive care unit with cyanosis and poor feeding. The infant was born at term to an unvaccinated mother without prenatal care. Vital signs are: heart rate 162 bpm, respiratory rate 50/min, blood pressure 62/38 mmHg, oxygen saturation 76% on room air, and temperature 37.1°C. On examination, a single loud S2 is appreciated at the left upper sternal border. Echocardiography demonstrates right ventricular hypertrophy, a large ventricular septal defect with rightward deviation of the ventricular septum, overriding of the aorta, and severe pulmonary stenosis with reduced pulmonary blood flow. Chest radiograph reveals a characteristic "boot-shaped" (coeur en sabot) cardiac silhouette with decreased pulmonary vascular markings. Which of the following is the most likely diagnosis?
Answer choices
- ATetralogy of FallotCorrect answer
- BTransposition of the great arteries with ventricular septal defect
- CHypoplastic left heart syndrome
- DPulmonary atresia with intact ventricular septum
- ETotal anomalous pulmonary venous return with obstruction
- FTricuspid atresia with patent ductus arteriosus
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