title: Pulmonary vein isolation by duty-cycled bipolar and unipolar radiofrequency energy with a multielectrode ablation catheter.
abstract: BACKGROUND
  Pulmonary vein (PV) isolation for ablation of atrial fibrillation (AF) remains a complex and lengthy procedure.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the feasibility and safety of a novel multielectrode catheter that delivers duty-cycled bipolar and unipolar radiofrequency (RF) energy.
  
  
  METHODS
  Patients eligible for catheter ablation of paroxysmal AF after screening with magnetic resonance imaging and transesophageal echocardiography were included in the study. A decapolar (3-mm electrode, 3-mm spacing, 25-mm diameter), circular, over-the-wire mapping and ablation catheter was deployed in the antrum of each PV. Ablation was performed with 60-second, 60 degrees C applications of duty-cycled bipolar/unipolar RF in a 4:1 ratio simultaneously at all selected electrode pairs until local activity was no longer observed. At 6 months, 7-day Holter monitoring was performed to determine freedom from AF without use of antiarrhythmic drugs.
  
  
  RESULTS
  In 98 patients (mean age 59 +/- 9 years), the PV ablation catheter was used for ablation of 369 veins (20 common left antra). All targeted veins (100%) were isolated as confirmed by the absence of potentials in the ostium either by PV ablation catheter or Lasso mapping. Mean number of RF applications was 27 +/- 7, total procedural time 84 +/- 29 minutes, and fluoroscopy time 18 +/- 8 minutes. Follow-up after 6 months without antiarrhythmic drugs showed freedom from AF in 83% of patients. No procedure-related complications were observed.
  
  
  CONCLUSIONS
  PV isolation by duty-cycled bipolar/unipolar low-power RF energy through a circular, decapolar catheter can be achieved safely and efficiently, with good efficacy at 6 months.
authors.affiliation: Cardiology Department, St. Antonius Hospital, Nieuwegein, The Netherlands. l.boersma@antonius.net
authors.forename: Lucas V A
authors.initials: LV
authors.lastname: Boersma
authors.forename: Maurits C E F
authors.initials: MC
authors.lastname: Wijffels
authors.forename: Hakan
authors.initials: H
authors.lastname: Oral
authors.forename: Eric F D
authors.initials: EF
authors.lastname: Wever
authors.forename: Fred
authors.initials: F
authors.lastname: Morady
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D018780:Body Surface Potential Mapping; D017115:Catheter Ablation / Q000295:instrumentation*; D017548:Echocardiography, Transesophageal; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000601:surgery*; D012189:Retrospective Studies; D016896:Treatment Outcome