Regional difference of optimal contact force to prevent acute pulmonary vein reconnection during radiofrequency catheter ablation for atrial fibrillation.

Optimal Contact Force for AF Ablation Background Regional differences in optimal contact force (CF) to prevent acute pulmonary vein reconnection (APVR) during catheter ablation for atrial fibrillation (AF) remain unclear. Objective The purpose of this study was to evaluate regional difference in optimal CF during AF ablation. Methods This single-center observational study evaluated data from 57 consecutive drug-refractory AF patients (mean age, 62 ± 11 years; 43 males) who underwent initial pulmonary vein isolation (PVI) using the THERMOCOOL® SMARTTOUCH™ (Biosense Webster, Diamond Bar, CA, USA) catheter from June to August 2013. APVR was defined as the time-dependent reconnection >20 minutes after initial PVI and/or reconnection evoked by intravenous adenosine administration (20 mg). Point-by-point relationships between the reconnected points and their CF values were evaluated. Results Total 72 gaps causing APVR were observed. Of a total of 4,421 ablation points, 285 (6.4%) were associated with APVR. The average CF value of the points with APVR was significantly lower than that of those without (APVR vs. no APVR; 7.5 ± 6.7 g vs. 9.9 ± 8.4 g; P < 0.0001). The areas under the curve and optimal CF values differed between segments (range 0.593–0.761 and 10–22 g, respectively). The optimal CF value was highest in bottom of the right PV and posterosuperior right PV segments (22 g) and lowest in posteroinferior right PV segment (10 g). Conclusions There was a regional difference in optimal CF values to prevent APVR, and the optimal CF value to prevent APVR with >95% probability was 10–22 g, depending on the individual peri-PV segments.