Daihiko Hakuno1, Takumi Toya2, Takeshi Adachi2. 1. Division of Cardiology, Department of First Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-0042, Japan. hakuno@ndmc.ac.jp. 2. Division of Cardiology, Department of First Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-0042, Japan.