In this study we reevaluated whether the sole cause of mitral valve prolapse (MVP) and aortic valve prolapse (AVP) is myxomatous degeneration. Forty-two surgical cases of prolapsed valves with mitral and/or aortic regurgitation were reviewed (AVP in nine, MVP in 27, and combined AVP and MVP [CVP]
MethodsForty-two consecutive surgical cases of regurgitant prolapsed valves and congestive heart failure at the University of Tokyo between 1978 and 1983 were reviewed. Twenty-five patients were men and 17 were women. Their ages ranged from 20 to 67 years (mean 43). Seven patients had a history suggestive of rheumatic fever. All patients had severe mitral (n = 27), aortic (n = 9), or combined mitral and aortic regurgitation (n = 6), and none had clinical valvular stenosis. The duration of symptoms ranged from 1 to 44 years (mean 12.8). The NYHA functional capacity was more than grade II in all patients. Atrial fibrillation was seen in 17 patients (63%) with mitral regurgitation, six (56%) with aortic regurgitation, and four (66%) with combined mitral and aortic regurgitation. This study did not include patients with atrial septal defect, ventricular septal defect, Marfan's syndrome, or other disease that may accompany mitral or aortic valve prolapse. The diagnosis of valve prolapse was made by two-dimensional echocardiographic and surgical findings.On two-dimensional echocardiography, mitral valve prolapse (MVP) was diagnosed when the mitral cusps protruded into the left atrium crossing the plane of the mitral anulus. During surgery, MVP was diagnosed by one surgeon when the intact valves protruded beyond the optimal position into the left atri-