Author: Aaron Lessen, M.D. Educational Pearls Atrial fibrillation is common. One of the best treatments for a fib is cardioversion back into sinus rhythm. Cardioversion may increase stroke risk if A-Fib duration is greater than 48 hours, but some new data suggests that this risk may happen as soon as 12 hours. However, newer studies show that cardioversion is generally safe as a treatment for A-Fib. References: Aatish Garg, Monica Khunger, Sinziana Seicean, Mina K. Chung, Patrick J.Tchou Incidence of Thromboembolic Complications Within 30 Days of Electrical Cardioversion Performed Within 48 Hours of Atrial Fibrillation Onset. JACC: Clinical Electrophysiology Aug 2016, 2 (4) 487-494; DOI: 10.1016/j.jacep.2016.01.018