The risk factors of AF include advanced age, transient atrial ischemia, arterial hypertension, dilated atria, male sex, pulmonary hypertension, previous atrial fibrillation and serum electrolyte disorders . On the other hand, there is evidence that cardiopulmonary bypass (CPB) time, duration of aortic cross clamping and the time of surgery, also the type of cardioplegia and the number of constructed grafts do not influence the incidence of AF.