title: Relation Between Left Atrial Wall Thickness in Patients with Atrial Fibrillation and Intracardiac Electrogram Characteristics and ATP-Provoked Dormant Pulmonary Vein Conduction.
abstract: BACKGROUND
  Atrial remodeling plays a key role in development of the substrate for atrial fibrillation (AF). Whether the wall thicknesses of the left atrium (LA) and pulmonary vein (PV)-LA junction affect remodeling and AF ablation is unknown. We investigated the relationship between wall thicknesses, electrogram characteristics, and adenosine triphosphate (ATP)-provoked dormant PV conduction as they pertain to AF.
  
  
  METHODS
  In 50 patients with AF and 25 patients without AF, wall thicknesses of the LA and PV-LA junction were measured on 320-slice computed tomography images. For the AF patients, NavX-based voltage maps generated during sinus rhythm were obtained, and ATP-provoked dormant PV conduction after PV isolation was evaluated.
  
  
  RESULTS
  Walls of the LA and PV-LA junction were significantly thicker in the AF patients than in the control patients (1.83 ± 0.29 mm vs. 1.59 ± 0.28 mm, respectively; P = 0.0010; and 0.88 ± 0.14 mm vs. 0.65 ± 0.11 mm, P<0.0001, respectively). Wall thickness at the PV-LA junction was independently associated with AF (β = 0.40, P = 0.0002). In AF patients, the walls of the PV-LA junction showed stepwise thickening across bipolar voltages indicative of severe (bipolar voltage <33rd percentile) to moderate (33rd-66th percentiles) to mild fibrosis/scarring (≥66th percentile). Walls of the PV-LA junction with dormant PV conduction were significantly thicker than those without it (0.94 ± 0.19 mm vs. 0.86 ± 0.21 mm, respectively; P = 0.0025).
  
  
  CONCLUSIONS
  Together, the association between thickened PV-LA junction walls and AF and the increased bipolar voltage suggests that such wall thickening increases PV electrical activities, leading to initiation and maintenance of AF and perhaps to ATP-provoked dormant PV conduction.
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Okumura
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Watanabe
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Nagashima
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Sonoda
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Sasaki
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Rikitake
authors.initials: R
authors.lastname: Kogawa
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Iso
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Kimie
authors.initials: K
authors.lastname: Ohkubo
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Nakai
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hirayama
mesh_terms: D000251:Adenosine Triphosphatases / Q000494:pharmacology*; D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology*; D064752:Atrial Remodeling / Q000502:physiology; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006325:Heart Atria / Q000473:pathology*; D006329:Heart Conduction System / Q000187:drug effects; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000187:drug effects*; D014057:Tomography, X-Ray Computed
chemical_list: D000251:Adenosine Triphosphatases
keywords: PA-LA junction wall thickness; atrial fibrillation; left atrial wall thickness