1. Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
2. National Cerebral and Cardiovascular Center, Suita, Japan
3. Japanese Red Cross Kumamoto Hospital, Kumamoto, Japan
4. Sakakibara Heart Institute, Tokyo, Japan
5. Yamagata Prefectural Central Hospital, Yamagata, Japan
6. Niigata Prefectural Shibata Hospital, Shibata, Japan
7. Ehime Prefectural Niihama Hospital, Niihama, Japan
8. Keio University School of Medicine, Tokyo, Japan
9. Jichi Medical University Saitama Medical Center, Saitama, Japan
10. Kumamoto University Graduate School of Medical Sciences, Kumamoto, Japan