1. From the Sleep Center (T.K., K.N.), Toranomon Hospital; Department of Cardiology (Y.U., Y.T., A.Y.), Tokyo Medical University, Tokyo, Japan; Cardiovascular Division (T. Yoshioka, S.-I.M.), Saitama Medical Center, Jichi Medical University, Saitama, Japan; Department of Cardiology (N.Y.), Juntendo University, School of Medicine; and Cardiovascular Center (T. Yamaguchi), Toranomon Hospital, Tokyo, Japan.