Atrial fibrillation after open heart surgery: how safe is early conversion without anticoagulation?

Postoperative atrial fibrillation (AF) is a common complication after cardiothoracic surgery, not only associated with an increased length of hospital stay but also predisposing patients to thromboembolic complications and stroke. Current guidelines advocate a therapeutic approach for postoperative AF that is fairly similar to the recommendations given for nonsurgical patients who develop AF. With respect to anticoagulation, heparin or oral anticoagulation is generally considered appropriate when the arrhythmia persists > 48 hours. The authors present the case of a patient developing sudden-onset, highly symptomatic AF 9 days after open-heart surgery, requiring pharmacologic treatment with amiodarone and metoprolol. Despite an early conversion to sinus rhythm, the patient subsequently developed a stroke, which echocardiographically was attributed to a highly mobile thrombus in the left atrial appendage. Surprisingly, good left atrial mechanical activity was observed. This raises the question of whether the early restoration of sinus rhythm without anticoagulation is safe in a postoperative setting.