These factors increasing the risk of postoperative AF were as follows in the order from high to low: the intraoperative blood transfusion was 58.404 times, the history of cardiac stents or angina pectoris was 48.813 times, the preoperative BNP ≥ 100 was 41.515 times, the male was 6.161 times, the over 70-year-old age was 5.044 times, the adhesion between lymph nodes and pericardium was 3.954 times and the open surgery was 3.357 times (Table 2). Here, NPPB is linked to atrial fibrillation.