1. From the Cardiovascular Center (M.T., M.Y., D.M., T.I., N. Kimata, K. Murai, N. Kobayashi, K.O., T.O., Y.S.) and Radiology Center (M.M.), Chiba-Hokusoh Hospital, Nippon Medical School, Chiba, Japan; and the Division of Cardiology (K. Mizuno), Nippon Medical School, Tokyo, Japan.