Does Location of Epicardial Adipose Tissue Correspond to Endocardial High Dominant Frequency or Complex Fractionated Atrial Electrogram Sites During Atrial Fibrillation?

Abstract

Background— Although increased epicardial adipose tissue (EAT) volume is known to be associated with increased prevalence of atrial fibrillation (AF), the exact mechanisms are unclear. Therefore, we investigated whether EAT locations were associated with high dominant frequency (DF) sites or complicated fractionated atrial electrogram sites during AF. Methods and Results— Three-dimensional reconstruction computed tomography images depicting EAT volumes (obtained by 320-detector-row multislice computed tomography) were merged with NavX-based DF and complicated fractionated atrial electrogram maps obtained during AF for 16 patients with paroxysmal AF and for 18 patients with persistent AF. Agreement between locations of the EAT, especially EAT surrounding the left atrium, and of high DF or complicated fractionated atrial electrogram sites was quantified. In addition, serum biomarker levels were determined. EAT surrounding the left atrium volumes was significantly greater in patients with persistent AF than in patients with paroxysmal AF (52.9 cm 3 [95% CI, 44.2–61.5] versus 34.8 cm 3 [95% CI, 26.6–43.0]; P =0.007). Serum high-sensitivity C-reactive protein and interleukin-6 levels were significantly higher in persistent AF patients than in paroxysmal AF patients (median high-sensitivity C-reactive protein, 969 ng/mL [interquartile range, 307–1678] versus 320 ng/mL [interquartile range, 120–660]; P =0.008; median interleukin-6, 2.4 pg/mL [interquartile range, 1.7–3.2] versus 1.3 [interquartile range, 0.8–2.4] pg/mL; P =0.017). EAT locations were in excellent agreement with high DF sites (κ=0.77 [95% CI, 0.71–0.82]) but in poor agreement with complicated fractionated atrial electrogram sites (κ=0.22 [95% CI, 0.13–0.31]). Conclusions— Increased EAT volume and elevation of inflammatory biomarkers are noted in persistent AF rather than paroxysmal AF patients. High DF sites are located adjacent to EAT sites. Thus, EAT may be involved in the maintenance of AF.

The Abundance of Epicardial Adipose Tissue Surrounding Left Atrium Is Associated With the Occurrence of Stroke in Patients With Atrial Fibrillation

“…10 In addition, serial research efforts have been dedicated to the exploration of the biological mechanisms that relate EAT and AF. 9,30–32 These mechanisms include: the actions of proinflammatory cytokines and the adipo-fibrokines released from EAT, such as activin A, which can induce fibrotic changes of the atrial myocardium; adipocyte infiltration of the atrial myocardium, which can cause blockage of local conduction and promote the micro-reentry circuit; and potential modulations of the autonomic nervous system by the ganglionic plexus within the EAT, which may influence the occurrence of AF. In this study, we comprehensively assessed the relationship between the periatrial EAT, the functional properties of the LA, and the circulatory stasis of LAA with contrast-enhanced MDCT and found that the amount of EAT around the LA was independently associated with AF-related stroke, based on a multivariate analysis.…”

Role of adipose tissue in the pathogenesis of cardiac arrhythmias

“…19 A neural mechanism of AF has also been described. In patients with AF high dominant frequency sites corresponded to EAT presence 60 . EAT volumes were higher in patients with permanent AF as opposed to paroxysmal AF.…”

Atrial Fibrillation Pathophysiology and Prognosis

“…In patients with AF, epicardial adipose tissue has been demonstrated to have increased inflammatory activity on 18-fluorodeoxyglucosepositron emission tomography compared with controls 104 and may also be implicated in the autonomic stimulation of the atria resulting in the triggering and maintenance of AF. 105 Pericardial fat volume has been highly associated with paroxysmal and persistent AF independent of age, LA size, hypertension, sex, valvular heart disease, LV ejection fraction, diabetes mellitus, and body mass index ( Figure 9). 106 Furthermore, total epicardial adipose volume and thickness have both been associated with LA volume.…”