[Mitral prolapse syndrome. Simple diagnosis of forms with severe arrhythmia].

The mitral valve prolapse syndrome encompasses a wide clinical spectrum with a majority of patients presenting with a benign course while a few present with severe arrhythmias. Nineteen patients with a systolic click and angiographic mitral valve prolapse were studied to determine which of several simple tests identified the subgroup with severe ventricular arrhythmias. The incidence and type of ventricular arrhythmias, documented by a 24 hour recording (Holter), were correlated with: 1) cardiac size assessed by the cardiothoracic ratio; 2) echocardiographic indices: end-diastolic septal and posterior wall thickness and left ventricular end-diastolic dimension; 3) a ten minute rhythm strip (mini-Holter). Only patients with ventricular hypertrophy (5 patients) or dilatation (7 patients) had frequent and severe arrhythmias. In these two subgroups, the cardiothoracic ratio was larger than in patients with a normal echocardiogram (7 patients). The ten minute rhythm strip was abnormal in all those patients with severe ventricular arrhythmias (ventricular tachycardia). Thus, in patients with mitral valve prolapse, the presence of an abnormal cardiothoracic ratio, echocardiogram and ten minute rhythm strip identifies patients with potentially severe ventricular arrhythmias. The mechanism of these arrhythmias is still poorly understood; however, a certain number of them may be related to a dysfunction of the autonomic nervous system.