1. Division of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Thoracic and Cardiovascular Surgery, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.
3. Department of Anesthesiology and Pain Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea.