1. Division of Cardiology, Department of Internal Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
2. Division of Cardiology, Department of Internal Medicine, Hallym Hospital, Incheon, Korea.
3. Division of Cardiology, Department of Internal Medicine, Kosin University School of Medicine, Busan, Korea.
4. Division of Cardiology, Department of Internal Medicine, NHIC Ilsan Hospital, Goyang, Korea.
5. Division of Cardiology, Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
6. Division of Cardiology, Department of Internal Medicine, Gachon University, Gil Medical Center, Incheon, Korea.