Mitral valve prolapse (MVP) is a common cause of mitral regurgitation (MR). Although most patients with MVP have mild, trivial, or no MR , it is the most common cause of surgical MR in developed countries . Other potential complications include infective endocarditis and arrhythmias. The diagnosis of MVP is suspected on physical examination and confirmed by echocardiography.
The definition, classification, etiology, pathology, and diagnosis of MVP will be reviewed here. Other aspects of MVP and associated MR are discussed separately. (See "Nonarrhythmic complications of mitral valve prolapse" and "Arrhythmic complications of mitral valve prolapse" and "Natural history of chronic mitral regurgitation in mitral valve prolapse and flail mitral leaflet" and "Mitral valve prolapse syndrome".)
The prevalence of mitral valve prolapse (MVP) in the general population varies among studies, mostly due to variable criteria used for diagnosis. Reports published early in the development of echocardiography suggested high MVP prevalence, 4 to 10 percent [3-5] and even close to 20 percent in selected populations. These early reports are now considered inaccurate because echocardiographic criteria for diagnosis were not yet fully developed and lacked specificity.
Using currently accepted definition of MVP, the Framingham Heart Study reported an overall prevalence of 2.4 percent . Individuals with classic MVP (leaflet thickness ≥5 mm; 1.3 percent) and non-classic MVP (leaflet thickness <5mm; 1.1 percent) had similar age and sex distributions. In another population-based study (Cardia), the prevalence of MVP in 4136 young adults was only 0.6 percent . In a Canadian study of 972 patients, MVP prevalence was similar in three ethnic groups (2.7 percent in South Asian, 3.1 percent in European, and 2.2 percent in Chinese) . MVP patients were leaner and had a greater degree of mitral regurgitation than the general population [6,7]. It is unclear whether prevalence differences between studies are age-related and should be interpreted as demonstrating a link between aging and MVP prevalence.
MVP may be slightly more common in women than in men. In the Framingham study, there was a nonsignificant trend toward a female preponderance among those with MVP (59.5 versus 52.7 percent in those without MVP) ; in the larger Olmsted county study, 64 percent of individuals with MVP were women .