1. From the Divisions of Cardiology (F.D.R., B.H., T.S., A.P., M.K., M.L., E.R.O.) and Cardiac Surgery (M.R.), University of Ottawa Heart Institute, Ottawa, ON; Department of Medicine (K.R.W.), Department of Diagnostic Imaging (R.H.), and Institute for Clinical Evaluative Sciences (S.H.), University of Ottawa, Ottawa, ON; and Division of Cardiology, Libin Cardiovascular Institute of Alberta, Calgary, AB (E.R.O.), Canada.