Right ventricular tachycardia: clinical and electrophysiologic characteristics.

TLDR

The study examined 30 patients without myocardial disease who presented with ventricular tachycardia characterized by left bundle branch block morphology and an inferior axis. Ventricular tachycardia was nonsustained in 80 % of patients, sustained in 20 %, provoked by exercise in 61 % of those tested, inducible in 73 % during electrophysiologic study, most often triggered by rapid pacing or isoproterenol, with endocardial mapping locating the earliest activation at the right ventricular outflow tract on the interventricular septum, the arrhythmias responded to a range of antiarrhythmic drugs, and over a mean 30‑month follow‑up no deaths or cardiac arrests occurred, with two patients in spontaneous remission and no new cardiac disease.

Abstract

This report describes the clinical and electrophysiologic characteristics of 30 patients without myocardial disease who had ventricular tachycardia with the morphologic characteristics of left bundle branch block and inferior axis. The tachycardias were nonsustained in 24 patients, sustained (greater than 30 sec) in six patients, and provocable by exercise in 14 of 23 patients undergoing a standard Bruce protocol. Ventricular tachycardia was induced during electrophysiologic study in 22 of 30 patients. Programmed stimulation induced tachycardia in 10 of 30 patients, most frequently by rapid atrial or ventricular pacing. Isoproterenol infusion facilitated tachycardia induction in 13 of 23 patients. Endocardial activation mapping, performed in 10 patients, confirmed that earliest ventricular activation during tachycardia occurred at the right ventricular outflow tract on the interventricular septum. These tachycardias were unique in their responsiveness to a wide variety of antiarrhythmic drugs, including type I drugs and propranolol. During a mean follow-up of 30 months, no patient has died or experienced cardiac arrest. Two patients appear to be in spontaneous remission, and no patient has developed additional signs of cardiac disease.