title: The impact of catheter ablation in the interpulmonary isthmus on atrial fibrillation ablation outcomes: a randomized study.
abstract: BACKGROUND
  Previous studies have underscored the importance of the interpulmonary isthmus in the initiation and maintenance of atrial fibrillation (AF). The efficacy of additional radiofrequency energy delivery in the interpulmonary isthmus following pulmonary vein antral isolation (PVAI) was investigated.
  
  
  RESULTS
  A total of 76 patients (49 males, mean age 56.8 ± 10.3) with drug-resistant paroxysmal (n = 64) and short-lasting persistent AF (n = 12) underwent PVAI. Patients were then randomly assigned to receive either "no further ablation" (group I, n = 38) or additional lesions in the interpulmonary isthmus of both ipsilateral pulmonary veins (group II, n = 38). There were no significant differences between study groups regarding the clinical and echocardiographic data. A trend towards a longer fluoroscopy time was observed in group II (P = 0.076). After a mean follow-up period of 11.1 ± 2.6 months, 22 patients in group I (57.9%) and 25 patients in group II (65.8%) were free from arrhythmia recurrence without any antiarrhythmic drug treatment after a single ablation procedure. The Kaplan-Meier arrhythmia-free survival curves showed no significant differences between study groups (P = 0.460).
  
  
  CONCLUSIONS
  Additional lesions in the interpulmonary isthmus following PVAI do not have incremental value in preventing AF recurrence.
authors.affiliation: Second Department of Cardiology, Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Athens, Greece.
authors.forename: Konstantinos P
authors.initials: KP
authors.lastname: Letsas
authors.forename: Michael
authors.initials: M
authors.lastname: Efremidis
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Vlachos
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Karlis
authors.forename: Louiza
authors.initials: L
authors.lastname: Lioni
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Asvestas
authors.forename: Kosmas
authors.initials: K
authors.lastname: Valkanas
authors.forename: Constantinos C
authors.initials: CC
authors.lastname: Mihas
authors.forename: Antonios
authors.initials: A
authors.lastname: Sideris
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D006328:Cardiac Catheterization / Q000009:adverse effects / Q000379:methods*; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods*; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D005260:Female; D006115:Greece; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D015641:Radiography, Interventional; D012008:Recurrence; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
keywords: atrial fibrillation; catheter ablation; electroanatomic mapping; interpulmonary isthmus; pulmonary vein isolation