Coronary Artery Disease USMLE Step 1 Practice Question
A 57-year-old woman with myxomatous mitral valve degeneration presents with dyspnea on exertion. Vital signs show BP 138/72 mmHg, HR 88/min, RR 18/min, SpO2 98% on room air. Echocardiography reveals severe mitral regurgitation with left ventricular enlargement and ejection fraction of 50%. She denies chest pain. She takes lisinopril and metoprolol. Compared with a normal heart, which of the following changes would most likely be seen on her left ventricular pressure-volume loop?
Answer choices
- ANo change in end systolic volume or diastolic filling
- BLoss of isovolumetric phases with increased end diastolic volumeCorrect answer
- CLeftward shift due to reduced preload
- DIncreased isovolumetric contraction and reduced end diastolic volume
- EMarkedly increased afterload with reduced stroke volume only
- FRightward shift of the loop with decreased stroke volume and reduced ejection fraction
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