Congenital Heart Disease USMLE Step 1 Practice Question
A 2-day-old newborn presents with cyanosis (SpO2 82%), tachypnea (RR 58/min), and tachycardia (HR 165/min). Echocardiography confirms all four pulmonary veins drain anomalously into the right atrium instead of the left atrium. Chest X-ray shows a normal cardiac silhouette without pulmonary edema. The infant has not received prostaglandin E1 infusion. Which of the following additional anatomic findings is required for survival in this patient?
Answer choices
- AComplete closure of the ductus arteriosus
- BAn intact ventricular septum
- CA route for blood to reach the left side of the heart such as an atrial septal defectCorrect answer
- DCalcification of the mitral valve
- ESevere left ventricular outflow obstruction
- FPatent foramen ovale with right-to-left shunting through the interventricular septum
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