1. Division of Cardiology, Department of Internal Medicine, Konyang University Hospital, Daejeon, Korea.
2. Division of Cardiology, Department of Internal Medicine, Cheongju Saint Mary’s Hospital, Cheongju, Korea.
3. Department of Emergency Medicine, Konyang University Hospital, Daejeon, Korea.
4. Department of Occupational & Environment Medicine, Konyang University Hospital, Daejeon, Korea.