Intraoperative map guided operation for atrial fibrillation due to mitral valve disease

Background. This study was designed to determine if intraoperative atrial a ctivation mapping facilitates operations for chronic atrial fibrillation as sociated with mitral valve disease. Methods. Surgical treatment guided by intraoperative electrophysiologic map ping was performed in 12 patients with chronic atrial fibrillation associat ed with isolated mitral valve disease. In 10 of 12 patients, regular and re petitive activation (cycle length ranged from 118 to 210 msec) originated i n the left atrial appendage and/or orifice of the left pulmonary vein. In t he remaining 2 patients, dominant repetitive activation and sporadic comple x activation were alternately observed in the left atrium. However, the act ivation sequence of the right atrium was extremely complex and chaotic. Results. On the basis of intraoperative mapping, surgical procedures, inclu ding resection of the left atrial appendage and/or cryoablation of the orif ice of the left pulmonary vein, were applied on the breakthrough site of th e repetitive activation. No surgical procedure was performed on the right a trium in II patients. Ten of 12 patients (83%) have maintained sinus rhythm for 6 to 40 months (average 24.8 months) after operation. Conclusions. In the majority of the patients with isolated mitral valve dis ease, the left atrium acts as an electrical driving chamber for chronic atr ial fibrillation. Computerized intraoperative mapping should guide surgeons in determining the appropriate surgical procedure for chronic atrial fibri llation. (C) 2000 by The Society of Thoracic Surgeons.