Treatment of catecholamine-sensitive right ventricular tachycardia by endocardial catheter ablation.

Endocardial catheter ablation with direct current high voltage shocks was performed in a patient with recurrent syncope due to a catecholamine-sensitive ventricular tachycardia that was drug refractory and occurred in the absence of identifiable heart disease. Pace mapping and catheter activation mapping of the spontaneous and isoproterenol-induced ventricular tachycardia located the tachycardia origin in the right ventricular outflow tract. Ablation dramatically reduced spontaneous ventricular tachycardia and ectopic activity (from 50,000 to less than 100 ectopic beats/24 h). The patient has remained symptom free and without ventricular tachycardia recurrence for 3 years. These observations and review of previous studies suggest that catheter mapping can easily locate the arrhythmia focus in the right ventricular outflow tract and that catheter ablation can be performed at low risk. Catheter ablation is a viable option for the treatment of right ventricular catecholamine-sensitive tachycardias that are unresponsive to antiarrhythmic drugs.