Valvular Heart Disease USMLE Step 1 Practice Question
A 42-year-old woman presents to the emergency department with progressive dyspnea, orthopnea, and nocturnal cough for 3 weeks. She reports a history of acute rheumatic fever at age 12 that was treated with antibiotics but no long-term penicillin prophylaxis was given. Vital signs: BP 128/76 mmHg, HR 108 bpm, RR 24/min, SpO2 87% on room air. On cardiac examination, a high-pitched, low-pitched rumbling diastolic murmur is heard best at the apex with the patient in the left lateral decubitus position. Bilateral crackles are present at lung bases. Chest X-ray shows pulmonary edema and straightening of the left heart border. Echocardiography reveals a mitral valve area of 1.1 cm² with a peak transmitral gradient of 18 mmHg. Which of the following best explains the pathophysiology of this patient's current clinical presentation?
Answer choices
- AChronic aortic regurgitation leading to volume overload and eccentric left ventricular hypertrophy
- BAcute bacterial endocarditis with vegetation-induced tricuspid regurgitation
- CMitral stenosis causing impaired left ventricular filling and pulmonary venous congestionCorrect answer
- DPulmonary hypertension from chronic left-to-right shunting through an atrial septal defect
- EAortic stenosis with preserved ejection fraction causing diastolic dysfunction
- FRestrictive cardiomyopathy with biatrial enlargement and restrictive filling pattern
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