1. Department of Internal Medicine, Keimyung University College of Medicine, Dongsan Medical Center, Daegu, Korea.
2. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Inje University College of Medicine, Ilsan Paik Hospital, Goyang, Korea.
4. Stanford University Medical Center, Cardiovascular Medicine, California, USA.
5. Department of Internal Medicine, Ajou University School of Medicine, Suwon, Korea.