Atrial fibrillation after cardiac operation: Risks, mechanisms, and treatment

Atrial fibrillation (AF) is a common complication of cardiac operations tha t leads to increased risk for thromboembolism and excessive health care res ource utilization. Advanced age, previous AF, and valvular heart operations are the most consistently identified risk factors for this arrhythmia. Dis persion of repolarization leading to reentry is believed to be the mechanis m of postoperative AF, but many questions regarding the pathophysiology of AF remain unanswered. Treatment is aimed at controlling heart rate, prevent ing thromboembolic events, and conversion to sinus rhythm. Multiple investi gations have examined methods of preventing postoperative AF, but the only firm conclusions that can be drawn is to avoid beta-blocker withdrawal afte r operation and to consider beta-blocker therapy for other patients who may tolerate these drugs. Preliminary investigations showing sotalol and amiod arone to be effective in preventing postoperative AF are encouraging, but e arly data have been limited to selective patient populations and have not a dequately evaluated safety. Newer class III antiarrhythmic drugs under deve lopment may have a role in the treatment of postoperative AF, but the risk of drug-induced polymorphic ventricular tachycardia must be considered. Non pharmacologic interventions under consideration for the treatment of AF in the nonsurgical setting, such as automatic atrial cardioversion devices and multisite atrial pacing, may eventually have a role for selected cardiac s urgical patients. (C) 2000 by The Society of Thoracic Surgeons.