title: Pulmonary vein isolation using "contact force" ablation: the effect on dormant conduction and long-term freedom from recurrent atrial fibrillation--a prospective study.
abstract: BACKGROUND
  Atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) is associated with PV to left atrium reconduction. Effective lesion creation necessitates adequate contact force between the ablation catheter and myocardium.
  
  
  OBJECTIVE
  The purpose of this study was to study the utility of contact force-guided ablation on immediate and long-term outcomes.
  
  
  METHODS
  Seventy-five patients with highly symptomatic paroxysmal AF underwent wide circumferential PVI using an irrigated-tip radiofrequency catheter. In 25 patients, ablation was guided by real-time contact force measurements (CF group; SmartTouch, Biosense Webster). A control group of 50 patients underwent PVI using a standard nonforce sensing catheter (standard group; ThermoCool, Biosense Webster). After PVI, all patients underwent adenosine testing to unmask dormant conduction. Patients were followed up at 3, 6, and 12 months and by transtelephonic monitoring as well.
  
  
  RESULTS
  Dormant conduction was unmasked and subsequently eliminated in 4 PV pairs (8%; 16% of patients) in the CF group and 35 PV pairs (35%; 52% of patients) in the standard group (P = .0004 per PV pair; P = .0029 per patient). The single-procedure, off-antiarrhythmic drug freedom from recurrent atrial arrhythmias at 1 year was 88% in the CF group vs 66% in the standard group (P = .047). Procedure duration and fluoroscopy time were significantly longer in the CF group (P = .0038 and P = .0001, respectively).
  
  
  CONCLUSIONS
  The use of real-time contact force guidance results in a significant reduction in the prevalence of dormant conduction with improved long-term freedom from recurrent arrhythmias. The utility of a contact force-guided approach requires evaluation in a long-term prospective randomized study.
authors: Electrophysiology Service at the Montreal Heart Institute and the Department of Medicine, Université de Montréal, Montreal, Canada; Department of Medicine, University of British Columbia, British Columbia, Canada. Electronic address: lmacle@mac.com.
authors: Jason G
authors: JG
authors: Andrade
authors: Florida Hospital Cardiovascular Institute, Orlando, Florida.
authors: George
authors: G
authors: Monir
authors: Florida Hospital Cardiovascular Institute, Orlando, Florida.
authors: Scott J
authors: SJ
authors: Pollak
authors: Electrophysiology Service at the Montreal Heart Institute and the Department of Medicine, Université de Montréal, Montreal, Canada.
authors: Paul
authors: P
authors: Khairy
authors: Electrophysiology Service at the Montreal Heart Institute and the Department of Medicine, Université de Montréal, Montreal, Canada.
authors: Marc
authors: M
authors: Dubuc
authors: Electrophysiology Service at the Montreal Heart Institute and the Department of Medicine, Université de Montréal, Montreal, Canada.
authors: Denis
authors: D
authors: Roy
authors: Electrophysiology Service at the Montreal Heart Institute and the Department of Medicine, Université de Montréal, Montreal, Canada.
authors: Mario
authors: M
authors: Talajic
authors: Department of Medicine, University of British Columbia, British Columbia, Canada.
authors: Marc
authors: M
authors: Deyell
authors: Electrophysiology Service at the Montreal Heart Institute and the Department of Medicine, Université de Montréal, Montreal, Canada.
authors: Léna
authors: L
authors: Rivard
authors: Electrophysiology Service at the Montreal Heart Institute and the Department of Medicine, Université de Montréal, Montreal, Canada.
authors: Bernard
authors: B
authors: Thibault
authors: Electrophysiology Service at the Montreal Heart Institute and the Department of Medicine, Université de Montréal, Montreal, Canada.
authors: Peter G
authors: PG
authors: Guerra
authors: Electrophysiology Service at the Montreal Heart Institute and the Department of Medicine, Université de Montréal, Montreal, Canada.
authors: Stanley
authors: S
authors: Nattel
authors: Electrophysiology Service at the Montreal Heart Institute and the Department of Medicine, Université de Montréal, Montreal, Canada.
authors: Laurent
authors: L
authors: Macle
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000601:surgery*; D012008:Recurrence; D016896:Treatment Outcome
keywords: Ablation; Adenosine; Atrial fibrillation; Contact force; Pulmonary vein electrophysiology; Pulmonary vein isolation