Endocardial and epicardial radiofrequency ablation in the treatment of atrial fibrillation with a new intra-operative device

Objective: Atrial fibrillation has been a difficult problem to solve in man y surgical patients, especially in those with mitral valve pathology. This study evaluates the results of endocardial and epicardial radiofrequency ab lation with a new intra-operative device in the treatment of atrial fibrill ation. Methods: We operated on 65 patients with atrial fibrillation, 58 of which had concomitant mitral surgery. Atrial fibrillation was chronic (over 1 year) in 46 patients (group A) and paroxysmal or recent onset in 12 (gro up B). Group C had lone artial fibrillation (two), concomitant coronary art ery disease (four) or a sarcoma tone). Bilateral pulmonary vein isolation w ith a new intra operative device was performed through multiple dry lesions in all patients. Groups A and B had endocardial applications at 70 degrees C during 60 s and group C had epicardial applications at 75 degrees C. Thr ee group C patients had epicardial applications off pump. Atrial wall biops ies were performed in nine patients from groups A and B. Results: There wer e no serious post-operative complications. At 1 month follow-up 54% of all patients were out of atrial fibrillation and 34% were in normal sinus rhyth m with bilateral atrial contraction (Santa Crus Score 4). At 6 months follo w-up, in spite of some crossover of patients among groups, similar results were obtained. The success of the procedure was 69% (Santa Crus scores 3 an d 4) in mitral patients with a left atrial volume smaller than 200 cm(3). P reliminary data on the transmurality of the lesions is presented. The patie nts submitted to epicardial radiofrequency ablation (group C) have satisfac tory results at 1 month(six out of seven were out of AF). Conclusions: Both endocardial and epicardial RF applications are simple and quick to perform and do not Dose an additional risk for most patients. Furthermore we belie ve that it is possible to perform bilateral epicardial radiofrequency ablat ion of the pulmonary veins without cardiopulmonary bypass. Further refineme nts of the technique are needed to assure transmurality of all lesions and better results. (C) 2000 Elsevier Science B.V. All rights reserved.