Affiliation: | 1. Department of Anaesthesiology and Pain Medicine, Cardiovascular Centre, Heart Research Institute, Chung-Ang University Hospital, Heukseok-dong, Dongjak-gu, Seoul, 156-755 Republic of Korea;2. Department of Thoracic and Cardiovascular Surgery, Cardiovascular Centre, Heart Research Institute, Chung-Ang University, Seoul, Republic of Korea |