title: Impact of left atrial appendage ridge ablation on the complex fractionated electrograms in persistent atrial fibrillation.
abstract: BACKGROUND
  The left atrial appendage (LAA) is a possible key contributor to the maintenance of persistent atrial fibrillation (PsAF). The effect of LAA ostial ablation on global left atrial higher-frequency sources remains unclear.
  
  
  METHODS
  Complex fractionated electrograms (CFEs) and dominant frequency (DF) maps acquired with a NavX system in 58 PsAF patients were enrolled and examined before and after LAA posterior ridge ablation, which followed a stepwise linear ablation.
  
  
  RESULTS
  High-density left atrial mapping identified continuous CFE sites in 50 % and high-DFs (≥ 8 Hz) in 53 % of patients at the LAA posterior ridge. In 44 patients in whom AF persisted despite pulmonary vein isolation (PVI) and linear ablation, LAA ablation significantly increased the mean CFE cycle length from 98 ± 29 to 108 ± 30 ms (P<0.0001) and decreased DF from 6.1 ± 0.8 to 5.9 ± 0.8 Hz (P<0.005) within the coronary sinus (CS). A multivariate analysis showed single-procedure failures could be predicted by the left atrial volume index and absence of continuous CFEs at the LAA posterior ridge region. The percent decrease in the global left atrial DF after LAA posterior ridge ablation was significantly lower in the patients with than in those without an enlarged left atrium (LA) (>90 mL/m(2)) (median 0 vs 4.8 %; P<0.01) and significantly lower in the patients with than in those without the absence of continuous CFEs in the LAA posterior ridge region (median 0.6 vs 4.8 %; P<0.05).
  
  
  CONCLUSIONS
  These findings suggested that an approach incorporating an LAA posterior ridge ablation was effective in modifying higher-frequency sources in the global LA in PsAF patients, but a lesser effect was documented in patients with electroanatomical remodeling of the LA.
authors: Department of Cardiology, Dokkyo Medical University Koshigaya Hospital, 2-1-50 Minami-Koshigaya, Koshigaya, Saitama, 343-8555, Japan, nshiro@dokkyomed.ac.jp.
authors: Shiro
authors: S
authors: Nakahara
authors: Yuichi
authors: Y
authors: Hori
authors: Akiko
authors: A
authors: Hayashi
authors: Sayuki
authors: S
authors: Kobayashi
authors: Hidehiko
authors: H
authors: Nakamura
authors: Yasuo
authors: Y
authors: Okumura
authors: Kan
authors: K
authors: Takayanagi
mesh_terms: D020517:Atrial Appendage / Q000601:surgery*; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D036542:Tomography, Spiral Computed; D016896:Treatment Outcome