1. From the Division of Cardiology (R.P.N., J.S.F., P.J.H., C.C.), University Health Network and Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; Departments of Medicine and Electrical and Computer Engineering (M.V.K.), McMaster University, Hamilton, Ontario, Canada; Unilever Corporate Research Biosciences (N.H., J.P., M.C., H.H., D.T.), Bedford, United Kingdom; University Health Network (M.H.C.), Toronto, Ontario, Canada.