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Effect of obesity and epicardial fat/fatty infiltration on electrical and structural remodeling associated with atrial fibrillation in a novel canine model of obesity and atrial fibrillation: A comparative study
Author(s) -
Otsuka Naoto,
Okumura Yasuo,
Arai Masaru,
Kurokawa Sayaka,
Nagashima Koichi,
Watanabe Ryuta,
Wakamatsu Yuji,
Yagyu Seina,
Ohkubo Kimie,
Nakai Toshiko,
Hao Hiroyuki,
Takahashi Rie,
Taniguchi Yoshiki,
Li Yxin
Publication year - 2021
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/jce.14955
Subject(s) - medicine , atrial fibrillation , obesity , fibrosis , cardiology , endocrinology , epicardial fat , beagle , adipose tissue
Background How obesity and epicardial fat influence atrial fibrillation (AF) is unknown. Methods To investigate the effect of obesity/epicardial fat on the AF substrate, we divided 20 beagle dogs of normal weight into four groups ( n = 5 each): one of the four groups (Obese‐rapid atrial pacing [RAP] group) served as a novel canine model of obesity and AF. The other three groups comprised dogs fed a standard diet without RAP (Control group), dogs fed a high‐fat diet without RAP (Obese group), or dogs fed a standard diet with RAP (RAP group). All underwent electrophysiology study, and hearts were excised for histopathologic and fibrosis‐related gene expression analyses. Results Left atrial (LA) pressure was significantly higher in the Obese group than in the Control, RAP, and Obese‐RAP groups (23.4 ± 6.9 vs. 11.4 ± 2.1, 11.9 ± 6.4, and 13.5 ± 2.9 mmHg; p = .005). The effective refractory period of the inferior PV was significantly shorter in the RAP and Obese‐RAP groups than in the Control group ( p = .043). Short‐duration AF was induced at greatest frequency in the Obese‐RAP and Obese groups ( p < .05). Epicardial fat/Fatty infiltration was greatest in the Obese‐RAP group, and greater in the Obese and RAP groups than in the Control group. %interstitial fibrosis/fibrosis‐related gene expression was significantly greater in the Obese‐RAP and RAP groups ( p < .05). Conclusions Vulnerability to AF was associated with increased LA pressure and increased epicardial fat/fatty infiltration in our Obese group, and with increased epicardial fat/fibrofatty infiltration in the RAP and Obese‐RAP groups. These may explain the role of obesity/epicardial fat in the pathogenesis of AF.