Thoracic epidural anesthesia does not influence the occurrence of postoperative sustained atrial fibrillation

Background. To evaluate whether thoracic epidural anesthesia (TEA) can redu ce the incidence of atrial. fibrillation (AE) after coronary artery bypass grafting (CABG). Methods. Forty-one patients undergoing CABG were treated with TEA intraoper atively and postoperatively. Another 80 patients served as the control grou p. The sympathetic and parasympathetic activities were evaluated by analysi s of neuropeptides, catecholamines and heart rate variability (HRV), preope ratively and postoperatively. Results. Postoperative AF occurred in 31.7% of the TEA-treated patients and in 36.3% of the untreated patients (p = 0.77). TEA significantly suppresse d sympathetic activity, as indicated by a less pronounced increase of norep inephrine and epinephrine (p = 0.03, p = 0.02) and a significant decrease o f neuropeptide Y (p = 0.01) postoperatively in TEA-treated patients compare d to untreated patients. The HRV variable expressing sympathetic activity w as significantly lower and the postoperative increase in heart rate was sig nificantly less in the TEA group than in the control group after surgery (p = 0.01, p < 0.001). Among patients developing AF, the maximal number of su praventricular premature beats per minute increased significantly in untrea ted patients postoperatively but remained unchanged in TEA-treated patients (p = 0.004 versus p = 0.86). Conclusions. TEA has no effect on the incidence of postoperative sustained AF, despite a significant reduction in sympathetic activity. (C) 2001 by Th e Society of Thoracic Surgeons.