1. The Heart Center of Chonnam National University Hospital, Chonnam National University Medical School, Gwangju, Korea.
2. Department of Nursing, Chonnam National University Hospital, Gwangju, Korea.
3. Department of Nursing, Chonnam National Univeristy College of Nursing, Gwangju, Korea.
4. Heart Research Center of Chonnam National University Hospital Designated by Korean Ministry of Health and Welfare and Family Affairs, Gwangju, Korea.