1. Division of Hypertension, National Cardiovascular Center, 5-7-1, Fujishirodai, Suita, Osaka 565, Japan
2. Division of Anesthesiology, National Cardiovascular Center, 5-7-1, Fujishirodai, Suita, Osaka 565, Japan
3. Division of Cardiovascular Surgery, National Cardiovascular Center, 5-7-1, Fujishirodai, Suita, Osaka 565, Japan
4. Research Institute, National Cardiovascular Center, 5-7-1, Fujishirodai, Suita, Osaka 565, Japan