1. Department of Thoracic and Cardiovascular Surgery, Bucheon Sejong Hospital , Bucheon, Gyeonggi-do, Republic of Korea
2. Department of Thoracic and Cardiovascular Surgery, Kangnam Sacred Heart Hospital, Hallym University Medical Center, Hallym University College of Medicine , Seoul, Republic of Korea
3. Division of Cardiology, Department of Internal Medicine, Bucheon Sejong Hospital , Bucheon, Gyeonggi-do, Republic of Korea