Current guidelines recommend anticoagulation with warfarin with documentation of an International Normalized Ratio (INR) of 2-3 for 3 weeks prior to cardioversion of persistent atrial fibrillation (AF). Achievement of adequate anticoagulation often takes longer than 3 weeks, increasing the time to cardioversion.
University of Florida, Division of Cardiovascular Medicine, College of Medicine, Clinical Electrophysiology Section, Gainesville, Florida 32610, USA. raycutro@hotmail.com