title: The different mechanisms between late and very late recurrences of atrial fibrillation in patients undergoing a repeated catheter ablation.
abstract: BACKGROUND
  The mechanisms of late (<1 year after the ablation) and very late (>1 year after the ablation) recurrences of paroxysmal atrial fibrillation (AF) after catheter ablation have not been reported.
  
  
  RESULTS
  Fifty consecutive patients undergoing a repeated electrophysiologic study to investigate the recurrence of paroxysmal AF after the first ablation were included. Group 1 consisted of 12 patients with very late (26 +/- 13 months) and group 2 consisted of 38 patients with late (3 +/- 3 months) recurrence of paroxysmal AF. In the baseline study, group 1 had a lower incidence of AF foci from the pulmonary veins (PVs) (67% vs 92%, P = 0.048) and a higher incidence of AF foci from the right atrium (50% vs 13%, P = 0.014) than group 2. In the repeated study, group 1 had a higher incidence of AF foci from the right atrium (67% vs 3%, P < 0.001) and a lower incidence of AF foci from the left atrium (50% vs 97%, P < 0.001), including a lower incidence of AF foci from the PVs (50% vs 79%, P = 0.07) and from the left atrial free wall (0% vs 29%, P = 0.046) than group 2. Furthermore, most of these AF foci (64% of group 1, 65% of group 2) were from the previously targeted foci.
  
  
  CONCLUSIONS
  The right atrial foci played an important role in the very late recurrence of AF, whereas the left atrial foci (the majority were PVs) were the major origin of the late recurrence of AF after the catheter ablation of paroxysmal AF.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Taipei Medical University School of Medicine, and Taipei Wan-Fang Hospital, Taipei, Taiwan.
authors.forename: Ming-Hsiung
authors.initials: MH
authors.lastname: Hsieh
authors.forename: Ching-Tai
authors.initials: CT
authors.lastname: Tai
authors.forename: Shih-Huang
authors.initials: SH
authors.lastname: Lee
authors.forename: Yung-Kuo
authors.initials: YK
authors.lastname: Lin
authors.forename: Hsuan-Ming
authors.initials: HM
authors.lastname: Tsao
authors.forename: Shih-Lin
authors.initials: SL
authors.lastname: Chang
authors.forename: Yenn-Jiang
authors.initials: YJ
authors.lastname: Lin
authors.forename: Wanwarang
authors.initials: W
authors.lastname: Wongchaoen
authors.forename: Kun-Tai
authors.initials: KT
authors.lastname: Lee
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012008:Recurrence; D012086:Reoperation; D016896:Treatment Outcome