Congenital Heart Disease USMLE Step 1 Practice Question
A 5-year-old girl with a history of uncorrected cyanotic heart disease now presents with dyspnea, syncope, and severe cyanosis. Physical examination reveals clubbing of the digits, polycythemia on CBC, and a loud single S2. Cardiac catheterization shows equal systemic and pulmonary artery pressures with bidirectional shunting. Which pathophysiologic consequence is most directly responsible for her current symptoms?
Answer choices
- ADecreased systemic vascular resistance
- BMitral stenosis progression
- CPulmonary vascular disease and increased pulmonary vascular resistanceCorrect answer
- DCoronary artery disease
- ELeft ventricular hypertrophy
- FRight atrial myxoma obstructing tricuspid valve flow
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