1. From the Cardiovascular Division, Faculty of Medicine, Tsukuba University, Japan (A.K.T., A.N., K.K., M.I., Y.S., K.A.); Department of Cardiology, Ogaki Municipal Hospital, Japan (I.M.); and Department of Heart Rhythm Management, Yokohama Rosai Hospital, Kanagawa, Japan (Y.O., S.K., Y.K., K.K.).