First human experience with pulmonary vein isolation using a through-the-balloon circumferential ultrasound ablation system for recurrent atrial fibrillation

Background-Standard mapping and ablation of focal sources of atrial fibrill ation are associated with very long procedure times and low efficacy. An an atomic approach to complete pulmonary vein isolation could overcome these l imitations. Methods and Results-Fifteen patients with atrial fibrillation refractory to medication underwent circumferential isolation of the pulmonary veins by u sing a novel catheter, with an ultrasound transducer (8-MHz) mounted near t he tip, in a saline-filled balloon. Twelve atrial foci and/or atrial fibril lation triggers were identified in 9 patients (pulmonary vein locations: le ft upper, 3; right upper, 6; right middle, 1; right lower, 1; and left infe rior, 1). In 5 patients, lesions were placed in the absence of any mapped t riggers. Irrespective of trigger mapping, circumferential isolation of both upper pulmonary Veins was attempted in all patients. The lower pulmonary v eins were ablated when sinus rhythm activation mapping revealed evidence of a sleeve of atrial muscle in the vein. The median number of lesions per pa tient required to isolate 1 pulmonary vein was 4 (range, 1 to 29). After ab lation, no evidence of narrowing was seen with repeat Venography or follow- up computed tomography scan. After a mean follow-up of 35 +/- 6 weeks, 5 pa tients had recurrence of atrial fibrillation. Three responded to drugs that were previously ineffective, and 2 remained in atrial fibrillation. Conclusions-This novel ultrasound ablation system can successfully isolate multiple pulmonary veins. At early follow-up, this approach seems to be eff ective in preventing recurrent atrial fibrillation in a significant number of patients.