1. From the Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario, Canada (H.U., R.S.B.B., I.B., R.A.d.K., A.S.L.T.); Divisions of Cardiology (E.F.) and Nuclear Medicine, McMaster University, Hamilton, Ontario, Canada (C.N.); and Heart Failure Research, Medtronic Inc, Minneapolis, Minn (M.R.S.H.).