title: Atrial tachycardia after circumferential pulmonary vein ablation of atrial fibrillation: mechanistic insights, results of catheter ablation, and risk factors for recurrence.
abstract: OBJECTIVE
  The aim of this study was to determine the mechanism of atrial tachycardia (AT) that occurs after ablation of atrial fibrillation (AF).
  
  
  BACKGROUND
  Patients who undergo catheter ablation of AF may develop AT during follow-up.
  
  
  METHODS
  Seventy-eight patients underwent an ablation procedure for AT after circumferential pulmonary vein ablation (CPVA) for AF. The 3-dimensional maps from the AF and AT procedures were compared to determine whether AT arose from a prior ablation line.
  
  
  RESULTS
  A total of 155 ATs were mapped, and the mechanism was re-entry in 137 (88%) and focal in 18 (12%). The most common left atrial (LA) ablation targets were the mitral isthmus, roof, and septum. The critical isthmus in 115 of the 120 LA re-entrant ATs (96%) traversed a prior ablation line, consistent with a gap-related mechanism. Catheter ablation was successful in 66 of the 78 patients (85%). After a mean follow-up of 13 +/- 10 months, 60 of the 78 patients (77%) were free of AT/AF without antiarrhythmic medications. Re-entrant septal AT was associated with recurrence (odds ratio 7.3; 95% confidence interval 1.5 to 36; p = 0.02), whereas PV isolation during the AT procedure was associated with a favorable outcome (odds ratio 0.17; 95% confidence interval 0.04 to 0.81; p = 0.03).
  
  
  CONCLUSIONS
  Approximately 90% of ATs after CPVA are re-entrant, and nearly all are related to gaps in prior ablation lines. These findings suggest that the prevalence of these arrhythmias may be reduced by limiting the number of linear lesions, demonstration of linear block, and pulmonary vein disconnection during the initial AF procedure.
authors.affiliation: Division of Cardiology, University of Michigan Hospitals, Ann Arbor, Michigan, USA.
authors.forename: Sanders
authors.initials: S
authors.lastname: Chae
authors.forename: Hakan
authors.initials: H
authors.lastname: Oral
authors.forename: Eric
authors.initials: E
authors.lastname: Good
authors.forename: Sujoya
authors.initials: S
authors.lastname: Dey
authors.forename: Alan
authors.initials: A
authors.lastname: Wimmer
authors.forename: Thomas
authors.initials: T
authors.lastname: Crawford
authors.forename: Darryl
authors.initials: D
authors.lastname: Wells
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Sarrazin
authors.forename: Nagib
authors.initials: N
authors.lastname: Chalfoun
authors.forename: Michael
authors.initials: M
authors.lastname: Kuhne
authors.forename: Jackie
authors.initials: J
authors.lastname: Fortino
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Huether
authors.forename: Tammy
authors.initials: T
authors.lastname: Lemerand
authors.forename: Frank
authors.initials: F
authors.lastname: Pelosi
authors.forename: Frank
authors.initials: F
authors.lastname: Bogun
authors.forename: Fred
authors.initials: F
authors.lastname: Morady
authors.forename: Aman
authors.initials: A
authors.lastname: Chugh
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects*; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins; D012008:Recurrence; D012086:Reoperation; D012307:Risk Factors; D013612:Tachycardia, Ectopic Atrial / Q000209:etiology* / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome