Prevalence of mitral valve prolapse in presumably healthy young men.

We determined the prevalence of mitral valve prolapse (MVP) in presumably healthy young men by studying 107 male house officers and medical students with cardiac auscultation in the supine, sitting and standing positions. Echocardiograms were performed at rest in the supine position before and after amyl nitrite inhalation and were obtainable in 101 subjects. Eleven of the 101 subjects had abnormal findings on auscultation: four had an isolated click and seven had a click and late systolic murmur. Correlation of the independent auscultatory and echocardiographic data in the 101 subjects showed that all seven of the subjects with a click and a murmur had echocardiographic evidence of prolapse. None of the 90 subjects with normal auscultation or the four with an isolated click had an abnormal echocardiogram. All seven subjects with MVP had thoracic skeletal abnormalities, but only one was symptomatic. These data suggest that the prevalence of MVP in healthy young males is similar to the reported 6-10% prevalence in healthy young females.