Serban C, et al. - Researchers assessed differences between obese and nonobese patients undergoing cardiac surgery in order to evaluate the role of body mass index in the evolution of de novo, early postoperative atrial fibrillation. During the first 5 postoperative days, they recorded continuous cardiac rhythms in obese (N = 67, 66 ± 9 years; 51 [76%] male) and nonobese (N = 89, 69 ± 9; 75 [84%] male) patients without a history of atrial fibrillation undergoing cardiac surgery. Outcomes revealed a larger number of prolonged atrial fibrillation episodes among obese individuals in the early postoperative period after cardiac surgery for coronary artery disease or valvular heart disease. On the third day in the early postoperative period, atrial fibrillation burden was particularly higher.