Intraventricular Wenckebach conduction and localized reentry in a case of right ventricular dysplasia with recurrent ventricular tachycardia.

Serial electrophysiologic studies were performed in a patient with recurrent ventricular tachycardia of left bundle branch configuration whose course and noninvasive evaluation are consistent with a diagnosis of right ventricular dysplasia. The localization of slowed conduction to the right ventricular apex, the reproducible initiation and termination of tachycardia with programmed extrastimuli and the presence of continuous electrical activity during tachycardia suggest a reentrant mechanism for this arrhythmia. Antiarrhythmic drugs further prolong the already fragmented apical electrogram and result in Wenckebach conduction within the abnormal portion of the right ventricle during pacing and tachycardia. Electrophysiologic findings are remarkably similar in studies performed 32 months apart.