Exercise left ventricular performance in patients with mitral valve prolapse.

Patients with mitral valve prolapse may, even in the absence of associated coronary artery disease or significant mitral regurgitation, have abnormality in exercise left ventricular function. The precise reason for this abnormality, which appears to be age and sex related, is not clear. Abnormal ejection fraction response to exercise cannot be predicted by the nature of symptoms, electrocardiographic changes, arrhythmias, or by extent and severity of mitral valve prolapse by echocardiography. Caution should therefore be exercised in diagnosing associated coronary artery disease based on the ejection fraction response to exercise per se or even on exercise-induced wall motion abnormality. Patients with prolapse, have reduced exercise tolerance, which has been ascribed to reduced left ventricular filling and smaller left ventricular end-diastolic volume in the upright position. Patients with mitral valve prolapse and associated coronary artery disease or significant mitral regurgitation often have, as expected, abnormal left ventricular function during exercise.