Tachyarrhythmias and triggering factors for atrial fibrillation after coronary artery bypass operations

Background. We evaluated the role of supraventricular arrhythmias and asses sed clinical predictors of atrial fibrillation (AF) that developed after co ronary artery bypass operations. Methods. Eighty patients, with a mean age of 65.8 years, underwent 24-hour Holter monitoring preoperatively and for 4 consecutive days postoperatively , or until clinically documented AF, for analysis of the number of prematur e beats and tachyarrhythmias. Atrial areas and atrial peptides were measure d preoperatively and postoperatively. Results. Twenty-nine of 80 (36.3%) patients had postoperative AF. Preoperat ively, the maximal supraventricular premature beats per minute were higher in the AF group (p = 0.02). The body mass index and total amount of cardiop legia were lower (p = 0.02 and p = 0.006, respectively), and withdrawal of P-blockers postoperatively more frequent (p = 0.001) in the AF group, but a trial areas and atrial peptides did not differ. Conclusions. Frequent supraventricular premature beats preoperatively may i ndicate a propensity for AF. A larger amount of cardioplegia during the cro ss-clamp period may reduce the risk of postoperative AF. Further studies ar e mandatory to clarify why patients with lower body mass index were more pr one to AF. (C) 2000 by The Society of Thoracic Surgeons.