Non-myxomatous mitral valve prolapse: a clinical and pathological study.

Mitral valve specimens from 9 patients with severe mitral regurgitation due to mitral valve prolapse were examined. All belonged to the age group 10-30 years and had rapid progression of their illness, requiring early surgery. The histopathological examination of valve tissue revealed varying degrees of fibrosis, increased vascularity and absence of myxomatous degeneration. These patients may represent a distinct group of mitral valve prolapse, whose clinical course is different from those with typical myxomatous degeneration of the mitral valve.