1. Division of Cardiology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
2. Division of Cardiology, Department of Internal Medicine, Yeungnam University Medical Center, Daegu, Korea.
3. Division of Cardiology, Department of Internal Medicine, Inje University Busan Paik Hospital, Busan, Korea.
4. Division of Cardiology, Department of Internal Medicine, Inje University Haeundae Paik Hospital, Busan, Korea.
5. Division of Cardiology, Department of Internal Medicine, Keimyung University Dongsan Medical Center, Daegu, Korea.