Catecholamine sensitive right ventricular outflow tract tachycardia: intraoperative mapping and ablation of a free-wall focus.

A patient with catecholamine-sensitive right ventricular outflow tract tachycardia refractory to pharmacological therapy underwent intraoperative mapping and cryoablation. Epicardial and endocardial mapping demonstrated earliest ventricular activation in the free-wall of the outflow tract, and cryoablation of the area resulted in surgical cure. No histologic abnormalities at the site of tachycardia origin were detected. Catecholamine sensitivity does not appear to result from a diffuse myocardial process, and permanent ablation of the tachycardia in this group of patients with a regional procedure is feasible.