1. Department of Medical Sciences, College of Medicine, Chungnam National University, 266 Moonhwa-lo, Daejeon 35015, Republic of Korea
2. Division of Cardiology, Department of Internal Medicine, Chungnam National University Hospital, 282 Moonhwa-lo, Daejeon 35015, Republic of Korea
3. Department of Cardiothoracic Surgery, Chungnam National University Hospital, 282 Moonhwa-lo, Daejeon 35015, Republic of Korea