Yoshihiko Morikawa1, Hiroshi Sakakibara2, Masaru Miura3,4. 1. Clinical Research Support Center, Tokyo Metropolitan Children's Medical Center, 2-8-29 Musashidai, Fuchu, Tokyo, 183-8561, Japan. morikawa@2005.jukuin.keio.ac.jp. 2. Department of General Pediatrics, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan. 3. Clinical Research Support Center, Tokyo Metropolitan Children's Medical Center, 2-8-29 Musashidai, Fuchu, Tokyo, 183-8561, Japan. 4. Department of Cardiology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.