1. Division of Cardiology, Department of Internal Medicine, Soonchunhyang University Cheonan Hospital, Cheonan, Korea.
2. Division of Cardiology, Department of Internal Medicine, Wonju Severance Christian Hospital, Wonju, Korea.
3. Division of Cardiology, Department of Internal Medicine, Korea University Anam Hospital, Seoul, Korea.
4. Division of Diagnostic Radiology, Korea University Anam Hospital, Seoul, Korea.