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.