Electrode catheter ablation for ventricular tachycardia: efficacy of a single cathodal shock.

Electrode catheter ablation was used to treat 11 distinct types of sustained ventricular tachycardias in eight patients. Rigid electrophysiological criteria were used to identify five left and five right ventricular arrhythmogenic sites; one of them gave rise to tachycardia with two distinct configurations. A single R-wave-synchronised 250 or 150 J cathodal shock was delivered at each site. One patient had mildly symptomatic episodes of sustained ventricular tachycardia during the first four days after the shock--there were no other complications. At discharge none of the patients was taking antiarrhythmic drugs. They were followed for 8-20 months (mean 14). Ablation abolished five of the 11 ventricular tachycardias. There was no recurrence in three of the eight patients. In two patients identical ventricular tachycardias recurred because the identification of the arrhythmogenic site was incorrect.