Predictors of conversion of atrial fibrillation after cardiac operation in the absence of class I or III antiarrhythmic medications

Background. Although risk factors for the development of atrial fibrillation (AF) after cardiac operations have been studied extensively, predictors of conversion to sinus rhythm within 24 hours of onset have not been examined. Methods. Eleven hundred consecutive adults undergoing cardiovascular operations from July 1997 to June 1998 were screened for new onset AF after operation. Patients with chronic persistent preoperative AF or those who died within 48 hours of the operation were excluded. Results. Three hundred fifty-three patients developed AF after operation; of these, 163 received therapy only for control of ventricular response, and 131 of the 163 (80%) converted to sinus rhythm within 24 hours. Logistic regression analysis determined that postoperative β-blocker use before the onset of AF, and the absence of severe LV dysfunction or diabetes, predicted reversion to sinus rhythm. Patients who converted had a shorter hospital stay and were more likely to be discharged in sinus rhythm. Conclusions. Atrial fibrillation resolves in most patients and it is possible to predict in which patients resolution is most likely, based on clinical data.