title: Effects of a high-fat diet on the electrical properties of porcine atria.
abstract: BACKGROUND
  Because obesity is an important risk factor for atrial fibrillation (AF), we conducted an animal study to examine the effect of a high-fat diet (HFD) on atrial properties and AF inducibility.
  
  
  METHODS
  Ten 8-week-old pigs (weight, 18-23 kg) were divided into two groups. For 18 weeks, five pigs were fed a HFD (HFD group) and five were fed a normal diet (control group). Maps of atrial activation and voltages during sinus rhythm were created for all pigs using the EnSite NavX system. Effective refractory period (ERP) and AF inducibility were also determined. When AF was induced, complex fractionated atrial electrogram (CFAE) mapping was performed. At 18 weeks, hearts were removed for comparing the results of histological analysis between the two groups. Body weight, lipid levels, hemodynamics, cardiac structures, and electrophysiological properties were also compared.
  
  
  RESULTS
  Total cholesterol levels were significantly higher (347 [191-434] vs. 81 [67-88] mg/dL, P=0.0088), and left atrium pressure was higher (34.5 [25.6-39.5] vs. 24.5 [21.3-27.8] mmHg, P=0.0833) in the HFD group than in the control group, although body weight only increased marginally (89 [78-101] vs. 70 [66-91] kg, P=0.3472). ERPs of the pulmonary vein (PV) were shorter (P<0.05) and AF lasted longer in the HFD group than in the control group (80 [45-1350] vs. 22 [3-30] s, P=0.0212). Neither CFAE site distribution nor histopathological characteristics differed between the two groups.
  
  
  CONCLUSIONS
  The shorter ERPs for the PV observed in response to the HFD increased vulnerability to AF, and these electrophysiological characteristics may underlie obesity-related AF.
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Okumura
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Watanabe
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Nagashima
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Sonoda
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Sasaki
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Rikitake
authors.initials: R
authors.lastname: Kogawa
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Iso
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Kimie
authors.initials: K
authors.lastname: Ohkubo
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Nakai
authors.affiliation: Department of Advanced Cardiovascular Imaging, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Takahashi
authors.affiliation: Institute of Medical Science, Medical Research Support Center, Section of Laboratory for Animal Experiments, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Taniguchi
authors.affiliation: Department of Pathology, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Mitsumata
authors.affiliation: Nihon Kohden Corporation Tokyo, Japan.
authors.forename: Mizuki
authors.initials: M
authors.lastname: Nikaido
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Ohyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hirayama
keywords: Atrial fibrillation; Electrical properties; High-fat diet