Atrial fibrillation (AF) is characterized by disorganized atrial electrical activity and is the most common form of tachyarrhythmia encountered in clinical practice.Primarily a disorder of the elderly AF is expected to have an increased impact on managed care as it accounts for considerable morbidity and mortality.Although effective nonpharmacological treatment modalities have emerged,antiarrhythmic drug therapy remains the treatment of choice for most AF patients.However,available drugs are far from ideal in terms of efficacy and safety.Drugs that target multiple ion channels determining myocardial depolarization and repolarization have been suggested to partly circumvent these setbacks with vernakalant and dronedarone approaching regulatory approval.This presentation will outline our strategy for identifying and developing such combined ion channel-blocking compounds as exemplified by AZD7009 and AZD1305.