Introduction
STAR AF II clinical trial demonstrated no benefit of either linear ablation or ablation of complex fractionated electrograms in addition to pulmonary vein isolation (PVI).1 However, the impact of PVI on the rhythm outcome was not enough in patients with persistent atrial fibrillation (AF). AF termination was considered the factor predicting freedom from arrhythmia recurrence in patients with persistent AF during long-term follow-up, but it was still in debate.2 The rate of AF termination during the procedure could range from 10 to 40%, which depended on the ablation strategy such PVI alone, PVI plus ablation of complex fractionated atrial electrograms (CFAEs), PVI plus a liner ablation or FIRM-guided ablation.2-5 Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) based computer simulation model has demonstrated that meandering re-entrant AF driver attached to patchy fibrosis.6 Boyle and Trayanova et al. have recently introduced a technology for the targeted ablation of persistent AF patients with atrial fibrosis, and demonstrated the feasibility of the technology to guide patient treatment in a prospective study of 10 patients. Although it was a proof-of -concept feasibility study of the technology, the AF termination rate and rhythm outcome were likely excellent.7 This indicated that the importance of targeting of the fibrotic tissue specifically associating with AF driver. We hypothesized that radiofrequency (RF) application on the patchy LGE site (PLS ablation) could eliminate the possible AF driver which resulted in AF termination and improving the rhythm outcome. The primary goal of this study was to determine whether the PLS ablation could terminate AF. The secondary goal was to determine whether the PLS ablation could improve the rhythm outcome as compared to the conventional ablation in patients with persistent AF.
Methods