title: Effects of inter-electrode spacing on complex fractionated atrial electrograms and dominant frequency detection.
abstract: BACKGROUND
  The influence of inter-electrode spacing (IES) on complex fractionated atrial electrograms (CFAEs) and dominant frequency (DF) detection was assessed.
  
  
  METHODS
  Bipolar electrograms were recorded via an octapolar catheter (2-mm electrode spacing) from left atrial CFAEs sites in 17 atrial fibrillation patients. The CFE-mean was calculated at IES of the electrode pairs 1-2, 1-3, 1-4, 1-5, and 1-6. The DF, regularity index (RI), and organization index (OI) were simultaneously analyzed.
  
  
  RESULTS
  The CFE-mean decreased as the IES increased (from 71 ± 15 ms of IES 1-2 to 61 ± 8 ms of IES 1-3, 57 ± 6 ms of IES 1-4, 57 ± 8 ms of IES 1-5, and 58 ± 9 ms of IES 1-6, respectively; IES 1-2 vs. 1-3 to 1-6, P < 0.01). The DF was unchanged (6.6 ± 1.6 Hz for all; P > 0.99). However, the RI decreased as the IES increased (from 0.30 ± 0.11 to 0.26 ± 0.11, 0.23 ± 0.11, 0.22 ± 0.12, and 0.20 ± 0.12; IES 1-2 vs. 1-3 to 1-6, P < 0.01), as did the OI (from 0.39 ± 0.14 to 0.34 ± 0.12, 0.32 ± 0.13, 0.29 ± 0.13, and 0.28 ± 0.13; IES 1-2 vs. 1-3 to 1-6, P < 0.01).
  
  
  CONCLUSIONS
  A wider IES might detect dyssynchronous activations, leading to a reduced CFE-mean and RI and OI. Therefore, bipolar signals recorded with a narrower IES might be preferable to more precisely localizing CFAEs and DF sites.
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, 30-1 Ohyaguchi Kamicho, Itabashi-ku, Tokyo, 173-8610, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Nagashima
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Okumura
authors.forename: Ichiro
authors.initials: I
authors.lastname: Watanabe
authors.forename: Toshiko
authors.initials: T
authors.lastname: Nakai
authors.forename: Kimie
authors.initials: K
authors.lastname: Ohkubo
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kofune
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kofune
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Mano
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Sonoda
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hirayama
mesh_terms: D001281:Atrial Fibrillation / Q000175:diagnosis*; D004562:Electrocardiography / Q000295:instrumentation* / Q000379:methods*; D004566:Electrodes; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity