1. Department of Cardiovascular Medicine, Tokyo Medical and Dental University , Yushima 1-5-45, Bunkyo-ku, Tokyo 113-8510 , Japan
2. Department of Cardiology, Yokosuka Kyosai Hospital , Yonegahama-dori 1-16, Yokosuka-shi, Kanagawa 238-8558 , Japan
3. Department of Cardiology, Japanese Red Cross Saitama Hospital , Shintoshin 1-5, Chuo-ku, Saiatama-shi, Saitama 330-8553 , Japan
4. Cardiovascular Division, Tsuchiura Kyodo Hospital , Otsuno 4-1-1, Tsuchiura-shi, Ibaraki 300-0028 , Japan
5. Department of Cardiology, Kameda Medical Center , Higashicho 929, Kamogawa-shi, Chiba 296-8602 , Japan
6. Department of Cardiology, University of Fukui Hospital , Shimoaizuki 2303, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui 910-1193 , Japan
7. Department of Cardiology, Japanese Red Cross Yokohama City Bay Hospital , Shinyamashita 3-12-1, Naka-ku, Yokohama-shi, Kanagawa 231-8682 , Japan
8. Department of Cardiology, Musashino Red Cross Hospital , Sakaiminami-cho 1-26-1, Musashino-shi, Tokyo 180-8610 , Japan
9. Department of Cardiology, Tokyo Metropolitan Hiroo Hospital , Ebisu 2-34-10, Shibuya-ku, Tokyo 150-0013 , Japan
10. Heart Center, Tokyo Yamate Medical Center , Hyakunin-cho 3-22-1, Shinjuku-ku, Tokyo 169-0073 , Japan
11. Department of Cardiology, Ome Municipal General Hospital , Higashiome 4-16-5, Ome-shi 198-0042 , Japan
12. Department of Cardiology, Hiratsuka Kyosai Hospital , Higashiome 4-16-5, Ome-shi 198-0042 , Japan