Prior to the strict criteria for the diagnosis of<unk> , as described above, the incidence of<unk>  in the general population varied greatly. Some studies estimated the incidence of<unk>  at 5 to 15 percent or even higher. One 1985 study suggested<unk>  in up to 35% of healthy teenagers. Recent elucidation of mitral valve anatomy and the development of three-dimensional echocardiography have resulted in improved diagnostic criteria, and the true prevalence of<unk>  based on these criteria is estimated at 2-3%. As a part of the Framingham Heart Study, for example, the prevalence of<unk>  in Framingham, MA was estimated at 2.4%. There was a near-even split between classic and nonclassic<unk> , with no significant age or sex discrimination.<unk>  is observed in 7% of autopsies in the United States. In a Taiwanese CHIEF heart study of Asian adult military personnel, it was estimated that out of 2442 people in Hualien aged 18 to 39,<unk>  occurred in 3.36%. People with<unk>  had lower body mass index, somatic symptoms related to exercise (chest pain, dyspnea, palpitations during exercise) and systolic click in auscultation. 7 out of 82 participants with<unk>  had mild pectus excavatum.
Mitral valve prolapse
Da Costa's syndrome  Da Costa's syndrome  1
Mitral regurgitation
Aortic regurgitation
Mitral stenosis
Tricuspid regurgitation
Tricuspid valve stenosis
Pulmonary valve stenosis