This document provides guidelines for the management of patients with atrial fibrillation from the American College of Cardiology, American Heart Association, and European Society of Cardiology. It was developed by a writing committee to update the 2001 guidelines. The guidelines contain recommendations on definition, classification, epidemiology, pathophysiology, evaluation, and management of atrial fibrillation. Evaluation and management strategies include pharmacological and non-pharmacological options for rate or rhythm control.