Chronic ventricular dysrhythmia in the mitral valve prolapse syndrome: frequency and clinical significance of ventricular site of origin

Twenty-two patients with the mitral valve prolapse-click syndrome and chronic ventricular dysrhythmia were judged to have either right or left ventricular premature contractions on the basis of electrocardiographic QRS configuration of the premature beats. The 11 patients with right-sided premature ventricular contractions (PVCs) were younger (P < .01), and had less abnormal electrocardiograms (NS) and fewer complications (NS) than those with left-sided PVCs. Coronary arteriograms performed on four in the latter group were normal, supporting a noncoronary etiology for the arrhythmia. Thus, patients with mitral valve prolapse and chronic ventricular dysrhythmia appear to have an equal prevalence of right- and left-sided premature complexes and, though not statistically significant, there was a consistent trend toward a more malignant course in the group with left ventricular premature complexes.