Combined endocardial and epicardial catheter ablation in arrhythmogenic right ventricular dysplasia incorporating scar dechanneling technique.

Background-Ventricular tachycardia (VT) ablation in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) has a low success rate. A more extensive epicardial (Epi) arrhythmogenic substrate could explain the low efficacy. We report the results of combined endocardial (Endo) and Epi VT ablation and conducting channel (CC) elimination. Methods and Results-Eleven consecutive patients with ARVD/C were included in the study. A high-density 3D Endo (321 +/- 93 sites mapped) and Epi (302 +/- 158 sites mapped) electroanatomical voltage map was obtained during sinus rhythm to define scar areas (<1.5 mV) and CCs inside the scars, between scars, or between the tricuspid annulus and a scar. The end point of the ablation procedure was the elimination of all identified CCs (scar dechanneling) and the abolition of all inducible VTs. The mean procedure and fluoroscopy time were 177 +/- 63 minutes and 20 +/- 8 minutes, respectively. Epi scar area was larger in all cases (26 +/- 18 versus 94 +/- 45 cm(2), P < 0.01). The combined Endo and Epi VT ablation eliminated all clinical and induced VTs, and the addition of scar dechanneling resulted in noninducibility in all cases. Seven patients continued on sotalol. During a median follow-up of 11 months (6-24 months), only 1 (9%) patient had a VT recurrence. There was a single major bleeding event that did not preclude a successful procedure. Conclusions-Combined Endo and Epi mapping reveals a wider Epi VT substrate in patients with ARVD/C with clinical VTs. As a first-line therapy, combined Endo and Epi VT ablation incorporating scar dechanneling achieves a very good short-and midterm success rate. (Circ Arrhythm Electrophysiol. 2012;5:111-121.)