[1] Natl Cerebral & Cardiovasc Ctr, Dept Cardiovasc Med, Div Cardiovasc Care Unit, Suita, Osaka 5658565, Japan
[2] Surugadai Nihon Univ Hosp, Dept Cardiol Cardiopulm Resuscitat & Emergency Ca, Tokyo, Japan
[3] Sapporo City Univ Hosp, Emergency & Crit Care Ctr, Sapporo, Hokkaido, Japan
[4] Yokohama City Univ, Crit Care & Emergency Med Ctr, Med Ctr, Yokohama, Kanagawa 232, Japan
[5] Osaka Mishima Emergency & Crit Care Ctr, Osaka, Japan
[6] Osaka City Gen Hosp, Emergency & Crit Care Med Ctr, Osaka, Japan
[7] Osaka Police Hosp, Div Cardiol, Osaka, Japan
[8] Saiseikai Senri Hosp, Senri Crit Care Med Ctr, Osaka, Japan
[9] Sumitomo Hosp, Dept Cardiol, Osaka, Japan
[10] Kagawa Univ Hosp, Emergency & Crit Care Ctr, Kagawa, Japan
[11] Yamaguchi Univ, Adv Med Emergency & Crit Care Ctr, Yamaguchi, Japan
[12] Kokura Mem Hosp, Div Cardiol, Kokura, Japan
[13] Natl Ctr Neurol & Psychiat, Dept Epidemiol & Biostat, Tokyo, Japan