Congenital Heart Disease USMLE Step 1 Practice Question
A cyanotic newborn presents with persistent SpO2 of 78% and HR 160 bpm. Echocardiography reveals tricuspid atresia with a hypoplastic right ventricle and an atrial septal defect allowing right-to-left shunting. Chest X-ray shows decreased pulmonary vascular markings. The infant has not received prostaglandin E1 therapy. Physical examination reveals no hepatomegaly. Which of the following additional findings is most likely present?
Answer choices
- ACompensatory patent ductus arteriosus or ventricular septal defect to permit pulmonary blood flowCorrect answer
- BLeft ventricular hypertrophy due to systemic outflow obstruction
- CVegetations on the pulmonic valve
- DComplete transposition without any septal communication
- ESevere aortic coarctation with upper extremity cyanosis only
- FPulmonary stenosis with right ventricular outflow tract obstruction limiting systemic blood flow
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