Effect of Left Posterior Pericardiotomy for the Prevention of POAF

Who May Qualify: - patients who are planned to undergo coronary artery bypass grafting - patients aged ≥19 years Who Should NOT Join This Trial: - patients who are planned to undergo other concomitant cardiac procedures (e.g. valve procedures, aorta procedures) - patients who undergo coronary artery bypass grafting using cardiopulmonary bypass - patients who are documented with paroxysmal, persistent, or permanent atrial fibrillation before operation - patients who have a history of cardiac surgery - patients who have a history of pericardial disease - patients who have severe adhesion at left pleural cavity which precludes effective left posterior pericardiostomy - patients who refuse to participate in this study Always talk to your doctor about whether this trial is right for you.