1. Department of Cardiology, Chonnam National University Hospital, Gwangju, Korea.
2. The Heart Center of Chonnam National University Hospital and Medical School, Gwangju, Korea.
3. Department of Cardiology, Chonnam National University Medical School, Gwangju, Korea.
4. Department of Preventive Medicine, Chonnam National University Medical School, Gwangju, Korea.