1. Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
2. Department of Cardiology, Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, Korea.
3. Division of Cardiology, Heart Institute, Asan Medical Center, University of Ulsan, Seoul, Korea.
4. Department of Internal Medicine, Heart Research Center of Chonnam National University, Gwangju, Korea.
5. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
6. Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
7. Department of Internal Medicine, Sungkyunkwan University College of Medicine, Seoul, Korea.
8. Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea.
9. Department of Internal Medicine, Kyungpook National University College of Medicine, Daegu, Korea.
10. Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.