Address for correspondence: Dr Bon-Kwon Koo, Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, 101 Daehang-ro, Chongno-gu, Seoul 110-744, Korea.; Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, South Korea
Doyeon Hwang, MD
Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, South Korea