title: Spatiotemporal organization of the left atrial substrate after circumferential pulmonary vein isolation of atrial fibrillation.
abstract: BACKGROUND
  There is a paucity of data regarding the mechanism of maintaining atrial fibrillation (AF) after pulmonary vein isolation (PVI) in patients with AF. The aim of this study was to examine the impact of circumferential PVI on the left atrial (LA) substrate characteristics.
  
  
  RESULTS
  Seventy-two AF patients (age, 53+/-11 years) underwent mapping and catheter ablation using an NavX system. The biatrial characteristics such as the complex fractionated atrial electrograms (CFEs; based on fractionated intervals) and frequency analysis (based on dominant frequencies) were mapped before and after PVI. PVI with electric isolation was performed in all patients. In the 45 patients who did not respond to PVI, the continuous CFEs (>8 seconds, 18+/-18% and 12+/-17% of the LA sites, before and after PVI, respectively, P=0.02), degree of LA fractionation (mean fractionated interval: 75.6+/-14.3 msec versus 87.3+/-16.7 msec, P=0.001), and mean LA dominant frequencies (6.92+/-0.88 Hz versus 6.58+/-0.91 Hz, P=0.001) decreased after PVI. Complete PVI altered the distribution of the CFEs toward the LA anteroseptum, mitral annulus, and LA appendage regions. A persistent presence of continuous CFEs in the vicinity of the dominant frequencies sites (observed in 53% patients) correlated with a higher procedural AF termination rate for the CFE ablation (63% versus 23%, P<0.05).
  
  
  CONCLUSIONS
  Complete PVI eliminated some CFEs in the LA and altered the distribution of the CFEs. The persistent presence of CFEs before and after PVI in the vicinity of the high frequency sites is important for AF maintenance after PVI.
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Yenn-Jiang
authors.initials: YJ
authors.lastname: Lin
authors.forename: Ching-Tai
authors.initials: CT
authors.lastname: Tai
authors.forename: Tsair
authors.initials: T
authors.lastname: Kao
authors.forename: Shih-Lin
authors.initials: SL
authors.lastname: Chang
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Lo
authors.forename: Ta-Chuan
authors.initials: TC
authors.lastname: Tuan
authors.forename: Ameya R
authors.initials: AR
authors.lastname: Udyavar
authors.forename: Wanwarang
authors.initials: W
authors.lastname: Wongcharoen
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Hu
authors.forename: Han-Wen
authors.initials: HW
authors.lastname: Tso
authors.forename: Wen-Chin
authors.initials: WC
authors.lastname: Tsai
authors.forename: Chien-Jung
authors.initials: CJ
authors.lastname: Chang
authors.forename: Kuo-Chang
authors.initials: KC
authors.lastname: Ueng
authors.forename: Satoshi
authors.initials: S
authors.lastname: Higa
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery*; D016279:Atrial Function, Left; D017115:Catheter Ablation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000601:surgery*; D016896:Treatment Outcome