Is atrial fibrillation caused by extracorporeal circulation?

Background. Atrial fibrillation is the most common rhythm disturbance encou ntered after open heart operations, with a reported incidence up to 40%. De spite its high incidence and clinical relevance its etiology remains obscur e. It has been hypothesized that atrial fibrillation might be related to ex tracorporeal circulation. We performed a retrospective study (January 1, 19 97 to December 31, 1997) comparing the incidence of atrial fibrillation in 3 groups of patients revascularized with and without extracorporeal circula tion. Methods. The first group comprised patients with coronary artery disease op erated on with standard revascularization technique with cardiopulmonary by pass (n = 685). The second group included patients who had minimally invasi ve coronary artery bypass grafting without the use of extracorporeal circul ation (n = 19). Patients in the third group had off-pump transmyocardial la ser revascularization (n = 19). Results. There was no significant difference in the incidence of atrial fib rillation in the group that had conventional coronary artery bypass and the group that had minimally invasive coronary artery bypass without cardiopul monary bypass. The incidence of atrial fibrillation was significantly lower in the transmyocardial laser group compared with the other two groups. Conclusions. The present study found that postoperative atrial fibrillation is not caused solely by extracorporeal circulation, but patients who had t ransmyocardial laser revascularization had a significantly lower incidence of atrial fibrillation. (Ann Thorac Surg 1999;68:931-3) (C) 1999 by The Soc iety of Thoracic Surgeons.