Jin Ok Jeong1, Yun Seon Park1, Jae Hyeong Park2. 1. Division of Cardiology, Department of Internal Medicine, Chungnam National University Hospital, Chungnam National University College of Medicine, Daejeon, Korea. 2. Division of Cardiology, Department of Internal Medicine, Chungnam National University Hospital, Chungnam National University College of Medicine, Daejeon, Korea. jaehpark@cnu.ac.kr.