[Mitral valve prolapse and severe rhythmic trouble (author's transl)].

Mitral valve prolapse is usually a benign affection, and yet but rather seldom, severe rhythmic troubles and even a sudden death may happen. The authors relate an observation about a seventeen years old young man presenting syncopes caused by ventricular fibrillation fit. The existence of a mitral valve prolapse is demonstrated by phonomecanogram and specially by echocardiogram which shows a telesystolic depression of the small valve. The observation is followed by commentaries about the frequency and clinic of Barlow syndrome. The rhythmic troubles liable to accompany this mitral damage are analysed and so is the evaluation of the risk of a sudden death by ventricular fibrillation.