Heart Failure USMLE Step 1 Practice Question
A 9-month-old male presents with cyanotic episodes triggered by crying during venipuncture. The mother reports the infant assumes a characteristic squatting position that relieves the cyanosis. Vital signs show HR 165/min, RR 48/min, SpO2 78% during crying, BP 95/60 mmHg, temp 37.2°C. Cardiac examination reveals a harsh systolic ejection murmur at the left upper sternal border. Chest X-ray demonstrates a "boot-shaped" heart with decreased pulmonary vascularity. The infant has never received digoxin. Which of the following is the most likely diagnosis?
Answer choices
- ATetralogy of FallotCorrect answer
- BCoarctation of the aorta
- CPatent ductus arteriosus
- DAtrial septal defect
- EVentricular septal defect
- FPulmonary stenosis with intact ventricular septum
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