The Effect of Fat Pad Modification during Ablation of Atrial Fibrillation: Late Gadolinium Enhancement MRI Analysis

Comprehensive Arrhythmia and Research Management (CARMA) Center, University of Utah School of Medicine, Salt Lake City, Utah.
Pacing and Clinical Electrophysiology (Impact Factor: 1.13). 01/2013; 36(4). DOI: 10.1111/pace.12084
Source: PubMed


Magnetic resonance imaging (MRI) can visualize locations of both the ablation scar on the left atrium (LA) after atrial fibrillation (AF) ablation and epicardial fat pads (FPs) containing ganglionated plexi (GP).

We investigated 60 patients who underwent pulmonary vein antrum (PVA) isolation along with LA posterior wall and septal debulking for AF. FPs around the LA surface in well-known GP areas (which were considered as the substitution of GP areas around the LA) were segmented from the dark-blood MRI. Then the FP and the ablation scar image visualized by late gadolinium enhancement (LGE)-MRI on the LA were merged together. Overlapping areas of FP and the ablation scar image were considered as the ablated FP areas containing GP. Patients underwent 24-hour Holter monitoring after ablation for the analysis of heart rate variability.

Ablated FP area was significantly wider in patients without AF recurrence than those in patients with recurrence (5.6 ± 3.1 cm(2) vs 4.2 ± 2.7 cm(2) , P = 0.03). The mean values of both percentage of differences greater than 50 ms in the RR intervals (pRR > 50) and standard deviation of RR intervals over the entire analyzed period (SDNN), which were obtained from 24-hour Holter monitoring 1-day post-AF ablation, were significantly lower in patients without recurrence than those in patients with recurrence (5.8 ± 6.0% vs 14.0 ± 10.1%; P = 0.0005, 78.7 ± 32.4 ms vs 109.2 ± 43.5 ms; P = 0.005). There was a significant negative correlation between SDNN and the percentage of ablated FP area (Y = -1.3168X + 118.96, R(2) = 0.1576, P = 0.003).

Extensively ablating LA covering GP areas along with PVA isolation enhanced the denervation of autonomic nerve system and seemed to improve procedural outcome in patients with AF.

Download full-text


Available from: Eugene G Kholmovski
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective The purpose of this review was to delineate our current knowledge of the close relationship between the abundance of epicardial adipose tissue (EAT) and the risk of all major cardiovascular disease, especially atrial fibrillation (AF). Data sources The data analyzed in this review were mainly from articles reported in PubMed published from 1972 to 2014. Study selection Original articles and critical reviews relevant to EAT and AF were selected. Results EAT, a particular form of metabolically active visceral fat deposited around the heart, is being regarded as an important independent predictor of cardio-metabolic diseases. EAT is composed of smaller adipocytes than other visceral fat depots and functioned like brown adipose tissue (BAT) to protect adjacent tissues. Improving the understanding of EAT in AF genesis and maintenance may contribute to prevent AF and reduce the complications associated with AF. Conclusion The findings suggest that EAT associates with AF severity and the recurrence of AF after catheter ablation even after adjustment for AF risk factors, but the precise mechanisms are not fully elucidated.
    No preview · Article · Jul 2014 · Chinese medical journal
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Epicardial adipose tissue (EAT) is located adjacent to high dominant frequency (DF) sites. Objective The relationship between the EAT location and efficacy of a combined high DF site and continuous complex fractionated activation electrogram (CFAE) site ablation is unclear. Methods Fifty-five non-paroxysmal AF patients (26 persistent and 29 longstanding) underwent pulmonary vein isolation (PVI) followed by a high DF site and continuous CFAE site ablation. High DF sites (DF ≥8Hz) and continuous CFAE sites (fractionated intervals ≤50ms) were targeted. The patients were divided into an AF-free group and AF-recurrent group. Results The AF freedom on antiarrhythmic drugs in persistent and longstanding persistent AF patients 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 the 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<0.01). 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%, NS). The overlap between the continuous CFAE sites and EAT did not differ between the two groups in both the LA and RA. Conclusions High DF sites that overlap with EAT may be important sources of AF. However, the contribution of the EAT to the AF substrate may differ between the LA and RA.
    No preview · Article · Oct 2014 · Heart Rhythm