1 Department of Cardiovascular Medicine, National Hospital Organisation Kagoshima Medical Center: Kokuritsu Byoin Kiko Kagoshima Iryo Center, 8-1, Shiroyama-cho, Kagoshima-shi, Kagoshima 892-0853, Japan.
2 Department of Cardiovascular Medicine, Kirishima Medical Center, Hayatocho-Matsunaga 3320, Kirishima-shi, Kagoshima 899-5112, Japan.