Congenital Heart Disease USMLE Step 1 Practice Question
A 2-week-old male infant born to a mother with untreated systemic lupus erythematosus presents with poor feeding and hepatomegaly. Vital signs show heart rate of 55 bpm, blood pressure 65/40 mmHg, respiratory rate 32/min, temperature 37.2°C, and SpO2 98% on room air. Electrocardiography demonstrates a prolonged PR interval progressing to complete heart block. Maternal anti-Ro/SSA antibodies are positive. The infant denies cyanosis. Which of the following is the most likely diagnosis?
Answer choices
- ACongenital heart block from maternal anti-Ro/SSA antibodiesCorrect answer
- BMyocarditis from viral infection
- CCongenital syphilis
- DLyme disease from in utero transmission
- EAtrioventricular canal defect
- FDilated cardiomyopathy from maternal enterovirus transmission
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