1. Division of Cardiology, Showa University Fujigaoka Hospital, 1-30 Fujigaoka, Yokohama City, Kanagawa 227-8501, Japan
2. Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
3. Division of Cardiology, Showa University Fujigaoka Rehabilitation Hospital, 2-1-1 Fujigaoka, Yokohama City, Kanagawa 227-8518, Japan
4. Laboratory of Cardiovascular Medicine, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan