Tomoko Tani1, Yukikatsu Okada2, Toru Kita3, Yutaka Furukawa3. 1. Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, 2-1-1 Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan. tomokot@kcho.jp. 2. Department of Cardiovascular Surgery, Kobe City Medical Center General Hospital, Kobe, Japan. 3. Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, 2-1-1 Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan.