title: Differences in the structural characteristics and distribution of epicardial adipose tissue between left and right atrial fibrillation.
abstract: Right atrial (RA) fibrillation (RAF) was previously characterized by initiation from RA ectopies, presence of a right-to-left dominant frequency gradient during atrial fibrillation (AF), and augmentation of the gradient by adenosine triphosphate infusion. We investigated structural characteristics of the bi-atria and epicardial adipose tissue (EAT) volume in patients with RAF.
  
  
  
  By using multidetector computed tomography, RA, left atrial (LA), right and LA appendage (RAA and LAA, respectively) volumes, pulmonary vein (PV) sizes, and EAT volumes were compared between the RAF group (n = 8) and LA fibrillation (LAF) group (n = 32). Compared with the LAF group, the LA volume was smaller (median 81.3 [95% CI, 74.2-88.5] vs. 64.5 [54.8-74.2] mL/m2; P = 0.04), the LAA volume was smaller (10.1 [9.0-11.3] vs. 6.5 [4.5-8.5] mL/m2; P = 0.008), and the RAA volume was larger (10.8 [9.1-12.4] vs. 14.1 [11.6-16.6] mL/m2; P = 0.044) in the RAF group. The RA volume was not significantly different between the groups (73.6 [66.8-80.3] vs. 68.1 [57.1-79.1] mL/m2; P = 0.47). The RAF group had smaller PVs (1.44 [1.33-1.55] vs. 1.12 [0.94-1.30] cm2/m2 for the left inferior PV; P = 0.01). Both the LA-EAT and RA-EAT volumes were smaller in the RAF group than the LAF group (4.2 [2.8-5.6] vs. 9.1 [7.8-10.4] mL/m2; P < 0.001 and 5.3 [4.3-6.3] vs. 9.5 [8.4-10.6] mL/m2; P < 0.001, respectively).
  
  
  
  RAF was structurally characterized by predominant RAA enlargement, small left atrium, and less EAT surrounding the atria. Electrical properties that determine the features of AF (RAF vs. LAF) may be genetically linked to structural properties.
authors.affiliation: Division of Arrhythmology, Shizuoka Saiseikai General Hospital, 1-1-1, Oshika, Suruga-ku, Shizuoka 422-8527, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Hasebe
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Division of Clinical Engineering, Shizuoka Saiseikai General Hospital, 1-1-1, Oshika, Suruga-ku, Shizuoka 422-8527, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Iida
authors.affiliation: Division of Clinical Engineering, Shizuoka Saiseikai General Hospital, 1-1-1, Oshika, Suruga-ku, Shizuoka 422-8527, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Hatano
authors.affiliation: Division of Clinical Engineering, Shizuoka Saiseikai General Hospital, 1-1-1, Oshika, Suruga-ku, Shizuoka 422-8527, Japan.
authors.forename: Toshiro
authors.initials: T
authors.lastname: Muramatsu
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nogami
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Aonuma
mesh_terms: D000200:Action Potentials; D000273:Adipose Tissue / Q000000981:diagnostic imaging* / Q000503:physiopathology; D050154:Adiposity; D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016279:Atrial Function, Left; D016280:Atrial Function, Right; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D010496:Pericardium / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011237:Predictive Value of Tests