title: Randomized comparison of encircling and nonencircling left atrial ablation for chronic atrial fibrillation.
abstract: BACKGROUND
  Left atrial (LA) circumferential ablation has been reported to eliminate atrial fibrillation (AF). Whether an ablation without encirclement of the pulmonary veins (PVs) is as effective as LA circumferential ablation is not clear.
  
  
  OBJECTIVE
  The purpose of this study was to compare the efficacy of LA circumferential ablation and nonencircling linear ablation in patients with chronic AF.
  
  
  METHODS
  Eighty patients with chronic AF were randomized to undergo LA circumferential ablation (n = 40) or nonencircling linear ablation (n = 40). In LA circumferential ablation, the PVs were encircled, with additional lines made in the mitral isthmus and posterior wall or roof. In nonencircling linear ablation, 4 +/- 1 ablation lines were created through areas of complex electrograms, with lines in the roof (38), anterior wall (36), septum (40), mitral isthmus (32), and posterior annulus (6). The endpoint of LA circumferential ablation and nonencircling linear ablation was voltage abatement.
  
  
  RESULTS
  LA flutter occurred in 15% after LA circumferential ablation and in 18% after nonencircling linear ablation (P = .8). A repeat ablation procedure was performed for recurrent AF in 7 and 11 patients or for atrial flutter in 6 and 4 patients after LA circumferential ablation and nonencircling linear ablation, respectively (P = .8). At 9 +/- 4 months, the prevalence of AF was 28% in the LA circumferential ablation and 25% in the nonencircling linear ablation group (P = .8). Sixty-eight percent and 60% of patients were in sinus rhythm and free of AF and atrial flutter in the absence of antiarrhythmic drug therapy after LA circumferential ablation and nonencircling linear ablation, respectively (P = .5). There were no complications.
  
  
  CONCLUSIONS
  Nonencircling linear ablation and LA circumferential ablation are equally efficacious in eliminating chronic AF. However, the advantage of nonencircling linear ablation is that it eliminates the need for ablation along the posterior wall of the LA. Therefore, nonencircling linear ablation may avoid the small but real risk of atrioesophageal fistula formation associated with LA circumferential ablation.
authors.affiliation: Division of Cardiovascular Medicine, University of Michigan, 1500 E. Medical Center Drive, Ann Arbor, MI 48109, USA. oralh@umich.edu
authors.forename: Hakan
authors.initials: H
authors.lastname: Oral
authors.forename: Aman
authors.initials: A
authors.lastname: Chugh
authors.forename: Eric
authors.initials: E
authors.lastname: Good
authors.forename: Petar
authors.initials: P
authors.lastname: Igic
authors.forename: Darryl
authors.initials: D
authors.lastname: Elmouchi
authors.forename: David R
authors.initials: DR
authors.lastname: Tschopp
authors.forename: S Scott
authors.initials: SS
authors.lastname: Reich
authors.forename: Frank
authors.initials: F
authors.lastname: Bogun
authors.forename: Frank
authors.initials: F
authors.lastname: Pelosi
authors.forename: Fred
authors.initials: F
authors.lastname: Morady
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D002908:Chronic Disease; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000503:physiopathology / Q000601:surgery*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000601:surgery; D016896:Treatment Outcome