Location of epicardial adipose tissue affects the efficacy of a combined dominant frequency and complex fractionated atrial electrogram ablation of atrial fibrillation.

Background: Epicardial adipose tissue (EAT) is located adjacent to high dominant frequency (DF) sites.

Objective: This study aimed to clarify the relationship between the EAT location and efficacy of a combined high DF site and continuous complex fractionated activation electrogram (CFAE) site ablation.

Methods: Fifty-five patients with nonparoxysmal atrial fibrillation (AF) (26 (47%) persistent and 29 (53%) long-standing persistent) underwent pulmonary vein isolation followed by high DF site and continuous CFAE site ablation. High DF sites (DF ≥8 Hz) and continuous CFAE sites (fractionated intervals ≤50 ms) were targeted. The patients were divided into an AF-free group and an AF-recurrent group.

Results: The AF freedom rate on antiarrhythmic drugs in patients with persistent and long-standing persistent AF was 88.5% and 75.9% over a 12-month follow-up period, respectively. The total EAT, left atrial (LA)-EAT, and right atrial (RA)-EAT volumes did not indicate significant differences between the AF-free and AF-recurrent groups. In the LA, the overlap between high DF sites and EAT was larger in the AF-free group than in the AF-recurrent group (57.0% ± 33.3% vs 22.6% ± 23.3%; P < .01). However, this overlap did not differ between the AF-free and AF-recurrent groups in the RA (20.4% ± 28.2% vs 19.0% ± 24.4%; P = .91). The overlap between continuous CFAE sites and EAT did not differ between the 2 groups in both the LA and the RA.

Conclusions: High DF sites that overlap with EAT may be important sources of AF. However, the contribution of EAT to the AF substrate may differ between the LA and the RA.