The present study is the first to demonstrate the importance of the overlap between high dominant frequency (DF) sites and epicardial adipose tissue (EAT) for the outcome of the catheter ablation of nonparoxysmal atrial fibrillation (AF). This result suggests that EAT may play an important
Location of epicardial adipose tissue affects the efficacy of a combined dominant frequency and complex fractionated atrial electrogram ablation of atrial fibrillation
Introduction
Growing evidence suggests the efficacy of the catheter ablation of atrial fibrillation (AF). In particular, circumferential pulmonary vein isolation (PVI) has become an established approach for AF ablation.1 However, the efficacy of PVI is sometimes insufficient in nonparoxysmal AF, and alternative approaches that target specific AF signals indicating the substrate responsible for AF perpetuation have been proposed.2, 3 Complex fractionated atrial electrograms (CFAEs), which are electrograms that demonstrate continuous fractionation and very short cycle lengths during AF, may represent the substrate of AF.2 In addition, atrial sites that represent local electrograms with high dominant frequencies (DFs) may be associated with AF maintenance.3 A recent study reported that a combined high dominant frequency (DF) site and continuous CFAE site ablation after PVI was effective in both paroxysmal and persistent AF.3
The close relationship between epicardial adipose tissue (EAT) and AF was previously reported.4, 5, 6 The periatrial EAT volume predicts the development of new-onset AF and is associated with the severity of AF.4 In addition, some studies have reported that EAT is associated with the outcome after AF ablation.4, 5 EAT is considered to induce electrical and structural remodeling of the atrium, leading to AF. Furthermore, a recent study suggested that EAT is located adjacent to high DF sites and may be involved in the maintenance of AF.6
These studies suggest that the location of EAT may provide useful information for catheter ablation targeting the substrate responsible for AF perpetuation.4, 5, 6 Thus, the present study aimed to clarify the relationship between the EAT location and efficacy of high DF site and continuous CFAE site ablation after PVI.
Section snippets
Study population
The present study included 55 patients (mean age 64 ± 9 years) with AF who underwent catheter ablation at our institution between April 2011 and September 2012. The patients included 26 (47%) with persistent AF (duration 7.2 ± 3.6 months) and 29 (53%) with long-standing persistent AF (duration 45.7 ± 26.2 years). Persistent AF was defined as AF lasting ≥7 days but <1 year, and long-standing persistent AF was defined as continuous AF lasting ≥1 year.7 All antiarrhythmic drugs were discontinued
Patient characteristics
The patient characteristics are summarized in Table 1. The mean age of all patients was 64 ± 9 years, and 14 (25)% were women. The body mass index and body surface area were 24.0 ± 2.7 kg/m2 and 1.7 ± 0.17 m2, respectively. Approximately half of the patients had long-standing persistent AF. Left atrial dilatation was observed in almost all patients; however, the left ventricular systolic function was preserved. The lipid and lipoprotein levels were within the normal range. The brain natriuretic
Major findings
The major findings of the present study were as follows: (1) the total EAT, LA-EAT, and RA-EAT volumes did not differ between the AF-free and AF-recurrent groups; (2) the overlap between high DF sites and EAT was significantly larger in the AF-free group than in the AF-recurrent group in the LA; and (3) the overlap between continuous CFAE sites and EAT did not differ between the 2 groups.
Previous studies regarding the AF substrate
CFAEs are considered to represent the rapid electrical activity from a driving source of AF12, 13; however,
Conclusion
The overlap between high DF sites and EAT may be an important factor for the efficacy of DF and CFAE site ablation. However, the contribution of EAT to the AF substrate may differ between the LA and the RA.
Acknowledgments
We thank Mr Naoki Hattori for his technical assistance.
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2017, Journal of ArrhythmiaCitation Excerpt :As the GP are unable to attach directly to the LA surface, the surrounding EAT may play an accessory role in receiving neural activity associated with the GP, and in producing pro-inflammatory adipokines [9]. Several studies have demonstrated the precise location of EAT through imaging modalities, and have suggested the presence of potential overlap between the EAT and GP areas during radiofrequency catheter ablation [10,11]. Therefore, EAT volume on the LA-PV junction area could represent an area of interconnected cardiac ANS tissue.
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2016, Journal of ArrhythmiaCitation Excerpt :The mapping parameter (CFAE-mean) was defined as an interval-analysis algorithm that measured the average index of the fractionation. Recordings at each site were 5 s in length [8,10,11]. A continuous CFAE was defined by an average fractionated interval (FI) of ≤50 ms, indicating a high degree of temporal stability of the fractionated electrograms maintaining AF [11,12].
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