Congenital Heart Disease USMLE Step 1 Practice Question
A 3-week-old male infant born at 28 weeks gestation presents with poor feeding and weight loss. On examination, he is tachypneic (RR 58/min), tachycardic (HR 172 bpm), and afebrile. A continuous 'machinery' murmur is heard at the left infraclavicular region. Hepatomegaly is noted on palpation. Chest X-ray demonstrates cardiomegaly with pulmonary edema and increased pulmonary vascular markings. Echocardiography confirms a patent ductus arteriosus (PDA) with significant left-to-right shunting and evidence of left atrial enlargement. The infant is currently on supplemental oxygen and mechanical ventilation. Which of the following is the most appropriate next step in management?
Answer choices
- AInitiate prostaglandin E1 infusion to maintain ductal patency
- BAdminister furosemide and fluid restriction while observing for spontaneous closure
- CStart indomethacin therapy to promote ductal closureCorrect answer
- DPerform immediate surgical ligation under emergency conditions
- EAdminister sildenafil to reduce pulmonary vascular resistance
- FInitiate milrinone infusion to improve cardiac contractility
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