1. Department of Cardiovascular Medicine, National Cardiovascular Center, Suita, Japan
2. Cardiovascular Center, Yokosuka Kyosai Hospital, Yokosuka, Japan
3. Department of Cardiology and Catheterization Laboratory, Shonan Kamakura General Hospital, Kamakura, Japan
4. Division of Cardiology, Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan