Atrial Fibrillation After Cardiac Surgery-comparing Conventional and Miniaturized Bypass Systems

Atrial fibrillation (AF) is the most common arrhythmia after cardiac surgery. The incidence of AF varies between 20 - 45 % after (coronary artery bypass grafting) CABG. It may lead to hemodynamic compromise, thromboembolic events, increased length of stay in the hospital and increased morbidity. The underlying cause of AF has been related to a variety of factors. Those most commonly related to the intraoperative management are the use of cardiopulmonary bypass (CPB), the influence of systemic inflammation, myocardial damage, intraoperative fluid management and the need of red blood cell transfusion. The purpose of the study is to find out the difference in the incidence of atrial fibrillation after CABG when using the conventional (CECC) or mini bypass system (MECC). The treatment protocol is similar in both groups except the CPB method (CECC vs. MECC). In both methods the investigators use MAQUET tubing and oxygenator. The investigators also collect special blood samples for determining most relevant factors found affecting in the incidence of AF.