1. Division of Cardiology, Department of Internal Medicine, Myongji Hospital, Goyang, Korea.
2. Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
3. Division of Cardiology, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University, Seoul, Korea.
4. Department of Cardiology, School of Medicine, Ewha Womans University, Seoul, Korea.
5. Department of Cardiology, Hanyang University Seoul Hospital, Seoul, Korea.
6. Division of Cardiology, Eulji University Hospital, Daejeon, Korea.
7. Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Seoul, Korea.
8. Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
9. Division of Cardiology, Department of Internal Medicine, Daegu Catholic University Medical Center, Daegu, Korea.
10. Division of Cardiology, Department of Internal Medicine, Chonnam National University Hospital, Chonnam National University School of Medicine, Gwangju, Korea.
11. Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.