With over 6 million patients affected only in the United States, atrial fibrillation (AF) is a major health problem with profound effects on both the individual patient and society at large. In this issue of Heart Failure Clinics, we have focused on AF and tried to cover the most important and relevant aspects in a comprehensive and contemporary review. A distinguished group of experts and leaders in basic and experimental electrophysiology, epidemiology, clinical pharmacology, interventional clinical electrophysiology, and cardiac surgery contributed state-of-the-art reviews and also shared their insight to the future of AF. Topics include but are not limited to: Risk Factors and Genetics of Atrial Fibrillation; Mechanisms of Atrial Fibrillation: Rotors, Ionic Determinants, and Excitation Frequency; Diagnostic Evaluation and Follow-Up of Patients with Atrial Fibrillation; Catheter Ablation of Atrial Fibrillation; Antithrombotic and Anticoagulant Therapy for Atrial Fibrillation; Postoperative Atrial Fibrillation: Incidence, Mechanisms, and Clinical Correlates; and Novel Upstream Approaches to Prevent Atrial Fibrillation Perpetuation.