Energy Dose and Cardioversion Outcomes in AF

This multicenter, randomized study will compare two electrical cardioversion energy strategies in adults with atrial fibrillation who are scheduled to undergo cardioversion during atrial fibrillation ablation or within 3 months after ablation. Eligible participants will be 18 to 80 years old, have a body mass index of at least 25 kg/m², and weigh more than 60 kg. Participants will be randomly assigned to one of two groups. The first group will receive an initial shock of 150 joules, increased to 200 joules if needed. The second group will receive an initial shock based on body weight: 300 joules for participants weighing less than 90 kg and 360 joules for those weighing 90 kg or more. If the initial shock does not restore normal heart rhythm, further shocks will be delivered according to the study protocol. The study will compare the proportion of participants in each group whose normal heart rhythm is restored shortly after cardioversion and whose rhythm remains stable. The study team will also record complications, changes in selected laboratory measures and quality of life, medication use, and treatment costs.