1. Division of Cardiology, Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, South Korea
2. Department of Cardiology, Chonnam National University Hospital, Gwangju, South Korea
3. Division of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, South Korea
4. Division of Cardiology, Inje University College of Medicine, Haeundae Paik Hospital, Busan, South Korea