1. Department of Internal Medicine, Haeundae Paik Hospital, Inje University College of Medicine
2. Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine
3. Department of Cardiology, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University
4. Department of Internal Medicine, Seoul St. Mary’s Hospital, College of Medicine, the Catholic University