Ventricular arrhythmias in syndrome of balloon deformity of mitral valve. Definition of possible high risk group.

Twenty patients clinically identified as having balloon deformity of the mitral valve were studied to assess the incidence of ventricular arrhythmias. Echocardiography and phonocardiography were used to confirm the nature of the mitral valve lesion. Continuous 24-hour electrocardiograms were obtained from all patients and analysed by a computer and 2 observers. One patient has ventricular fibrillation and 3 patients had ventricular tachycardia. There was a high incidence of other less severe forms of ventricular arrhythmias. Eight patients had inferolateral ST and T wave abnormality on the resting electrocardiogram, and were described as having the ausculatatory-electrocardiographic variant of the balloon mitral valve syndrome. The occurrence of serious ventricular arrhythmias (ventricular fibrillation and tachycardia) was significantly more frequent in this group. This raises the possibility that the resting electrocardiogram may identify those patients with balloon deformity of the mitral valve who are at risk from sudden death.