Congenital Heart Disease USMLE Step 1 Practice Question
A term newborn male presents with cyanosis and ashen appearance at 6 hours of life. Vital signs show BP 60/40 mmHg, HR 165/min, RR 48/min, SpO2 78% on room air. Echocardiography reveals severe hypoplasia of the left ventricle with retrograde aortic flow; ascending aorta measures 4 mm. Chest X-ray shows normal pulmonary vascularity. He has not received prostaglandin therapy. Which intervention is most critical to maintain systemic perfusion before surgical management?
Answer choices
- AStart high dose beta blockade
- BAdminister inhaled nitric oxide only
- CInfuse prostaglandin E1 to maintain ductal patencyCorrect answer
- DGive adenosine to slow the heart rate
- EAdminister indomethacin to close the ductus arteriosus
- FPerform immediate balloon atrial septostomy to increase left ventricular preload
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