Anticoagulation for cardioversion of atrial fibrillation

A trial fibrillation (AF) is a common arrhythmia associated with a broad spectrum of underlying diseases that include systemic hypertension, rheumatic heart disease and coronary artery disease.1 Several studies have documented the strong relation between chronic AF and emboli.2,3 In addition, an increased risk of embolism exists in the setting of cardioversion of AF to sinus rhythm.4,5 In the best study to date, Bjerkelund and Orning6 reported on 572 attempted cardioversions in 437 patients and observed a 0.8% incidence of embolization in long-term anticoagulated patients compared with 5.3% in a nonanticoagulated group. Shortcomings of this study included lack of randomization, no evaluation of shortterm therapy and inclusion of arrhythmias such as atrial flutter and atrial tachycardia. Based on such work, current recommendations include anticoagulation for 2 to 4 weeks before cardioversion to allow adherence and endothelialization of existing thrombus and 1 to 4 weeks after cardioversion to provide coverage for late resumption of atrial activity.7,8 The present report evaluates these recommendations in light of our experience over the past 10 years.