1 Division of Cardiology, Department of Internal Medicine, Eunpyeong St. Mary's Hospital, the Catholic University of Korea, Seoul, Korea.
2 Division of Cardiology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
3 Division of Cardiology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. mdyhkim@amc.seoul.kr.