Spontaneous resolution of severe mitral regurgitation in a patient with a flail mitral valve.

Flail mitral valve usually causes severe mitral regurgitation, which may lead to left ventricular dysfunction if left uncorrected. The authors present a case of flail posterior mitral valve leaflet and severe mitral regurgitation in which mitral valve adaptation led to enlargement of the anterior mitral valve leaflet, decrease in mitral regurgitation, and reverse left ventricular remodeling without any need for surgery.