title: Surgical ablation of atrial fibrillation with a novel bipolar radiofrequency device.
abstract: OBJECTIVE
  When used for epicardial ablation, unipolar devices do not predictably yield transmural scars. Bipolar radiofrequency proved highly effective on the animal model, but clinical experience is still initial. We describe acute electrophysiologic findings and follow-up results of epicardial ablation with a novel bipolar radiofrequency device.
  
  
  METHODS
  A bipolar ablator was used to perform a simplified left atrial lesion set in 90 consecutive patients with atrial fibrillation undergoing open heart surgery. Pacing thresholds were assessed during surgery to validate 24 pulmonary vein encircling lines (12 patients). Follow-up was 100% complete.
  
  
  RESULTS
  In 67 of 90 patients (84%), mitral valve disease was the main indication to surgery. Atrial fibrillation was continuous in 74 patients (82%) and intermittent in 16 patients (18%). Pacing threshold assessment showed a complete conduction block in 22 of 24 pulmonary vein couples (92%) after a single ablation and in all patients after doubling of the encircling lines. No complications related to the ablation procedure were recorded. The sinus rhythm restoration rate was 79% at 3 months, 87% at 6 months, and 89% (17/18 patients) at 1 year. Postablation organized arrhythmias consisted in right atrial flutter in 2 patients (2%) and left atrial flutter in 6 patients (7%).
  
  
  CONCLUSIONS
  Epicardial ablation with bipolar radiofrequency grants acute transmurality. A simplified lesion set proved highly effective in eliminating atrial fibrillation at 1-year follow-up. Our data suggest that addition of a lesion to the mitral annulus is advisable to prevent left atrial flutter.
authors.affiliation: Division of Cardiac Surgery, S Raffaele Univeristy Hospital, Milan, Italy. stefano.benussi@hsr.it
authors.forename: Stefano
authors.initials: S
authors.lastname: Benussi
authors.forename: Simona
authors.initials: S
authors.lastname: Nascimbene
authors.forename: Giliola
authors.initials: G
authors.lastname: Calori
authors.forename: Paolo
authors.initials: P
authors.lastname: Denti
authors.forename: Zvi
authors.initials: Z
authors.lastname: Ziskind
authors.forename: Samer
authors.initials: S
authors.lastname: Kassem
authors.forename: Giovanni
authors.initials: G
authors.lastname: La Canna
authors.forename: Carlo
authors.initials: C
authors.lastname: Pappone
authors.forename: Ottavio
authors.initials: O
authors.lastname: Alfieri
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000150:complications; D006349:Heart Valve Diseases / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D016896:Treatment Outcome