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.