Surgical ablation of atrial fibrillation with a novel bipolar radiofrequency device.
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.
Benussi
Stefano
S
Division of Cardiac Surgery, S Raffaele Univeristy Hospital, Milan, Italy. stefano.benussi@hsr.it
Nascimbene
Simona
S
Calori
Giliola
G
Denti
Paolo
P
Ziskind
Zvi
Z
Kassem
Samer
S
La Canna
Giovanni
G
Pappone
Carlo
C
Alfieri
Ottavio
O
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