U-wave alterations: singular noninvasive electrocardiographic diagnostic markers.

the morphologic characteristics of the mitral valve (i.e., simple mitral valve prolapse vs. flail leaflet or the presence of severe myxomatous infiltration), cannot yet be analyzed. Recently, it has been suggested that mitral valve prolapse is uniformly a good prognosis (3). It is unclear how these various components of the clinical presentation of patients with mitral valve diseases contribute to the outcome, in particular to the risk of sudden death. We agree that further studies are needed on the outcome of various types of mitral valve disease. Such studies will require analysis of large population-based groups of patients with mitral valve disease. At this point, our study allows us to define the notable risk of sudden death incurred under conservative management by patients with flail leaflets, who represent a large group of candidates for surgical correction of mitral regurgitation.