Feasibility of a noncontact catheter for endocardial mapping of human ventricular tachycardia.

BACKGROUND Catheter ablation of ventricular tachycardia (VT) is limited by difficulty in identifying suitable sites for ablation. This study assesses use of a system capable of simultaneous endocardial mapping of the human left ventricle to map and guide radiofrequency (RF) catheter ablation of VT. METHODS AND RESULTS A catheter-mounted noncontact multielectrode array was used to reconstruct 3360 electrograms, superimposed onto a computer-simulated endocardial model. Of 24 patients studied, 20 had ischemic heart disease. Exit sites were demonstrated by the noncontact system in 80 (99%) of 81 VTs, with complete VT circuits traced in 17 (21%). In another 37 VTs, 36+/-30% (mean+/-SD) of the diastolic interval was identified. Thirty-eight VT morphologies were ablated with 154 RF energy applications. Successful ablation was achieved by 77% of RF applications to relevant diastolic activity identified by the system and was significantly more likely (P<0.0001) than by RF at the VT exit or remote from diastolic activation. Over a mean follow-up of 1.5 years, 14 patients (64%) have had no recurrence of VT, and only 2 target VTs (5.3%) have recurred. Five patients have had recurrence of other VTs. CONCLUSIONS This noncontact mapping system identified diastolic portions of the circuit in most VTs studied and can safely map and guide ablation of human VT.