Mitral valve prolapse: a cardiomyopathic state?

Patients with diseases of the myocardium, structural abnormalities of the heart, and valvular disease may have mitral valve prolapse demonstrated as a consequence of these disease entities. However, there appears to be a primary disease of the mitral leaflets in which left ventricular cineangiography has demonstrated abnormal contraction patterns of the left ventricle in some patients. The cause of these abnormal contraction patterns is controversial, but most of the evidence points to these abnormalities being a consequence of the abnormal leaflet tissue motion during systole creating abnormal stress on the papillary muscles and supporting left ventricle wall. Biopsy evidence of myocardial changes and abnormal cardiac metabolic studies in some patients have suggested that myocardial function may not be entirely normal in every patient with mitral valve prolapse. However, there is not sufficient evidence currently to ascribe these histologic, metabolic and angiographic changes to a primary cardiomyopathic condition.