Phased-array intracardiac Echocardiography monitoring during pulmonary vein isolation in patients with atrial fibrillation - Impact on outcome and complications

Background - The objective of this study was to assess the impact of intracardiac echocardiography ( ICE) on the long-term success and complications in patients undergoing pulmonary vein isolation ( PVI) for treatment of atrial fibrillation (AF). Methods and Results - Three hundred fifteen patients underwent PVI for treatment of AF. Each patient underwent ostial isolation of all PVs using a cooled-tip ablation catheter. PVI was performed using circular mapping ( CM) alone ( group 1, 56 patients), CM and ICE ( group 2, 107 patients), and CM and ICE with titration of radiofrequency energy based on visualization of microbubbles by ICE ( group 3, 152 patients). After a mean follow-up time of 417 +/- 145 days, 19.6% (11 of 56), 16.8% (18 of 107), and 9.8% (15 of 152) of patients in groups 1, 2, and 3 experienced recurrence of AF, respectively. Moreover, whereas no group 3 patient experienced severe (> 70%) PV stenosis, severe PV stenosis was documented in 3 (3.5%) of 56 patients in group 1 and in 2 (1.8%) of 107 patients in group 2 ( P < 0.05). No embolic events were detected in group 3 patients. Conclusions - Intracardiac echocardiography improves the outcome of cooled-tip PVI. Power adjustment guided by direct visualization of microbubble formation reduces the risk of PV stenosis and improves long-term cure.