1. 1School of Nursing, College of Medicine, Soonchunhyang University, Asan, Republic of Korea
2. 2Department of Internal Medicine, Daejeon Eulji Medical Center, Eulji University College of Medicine, Daejeon, Republic of Korea
3. 3Cardiovascular Center, Korea University Guro Hospital, Seoul, Republic of Korea
4. 4Division of Cardiology, Department of Internal Medicine, Chonnam National University Hospital, Gwangju, Republic of Korea