1. Population Health Research Institute (A.P.B., S.J.C., J.S., D.C., W.F.M., J.D.R., J.A.W., R.Z., J.S.H.), Hamilton, ON, Canada.
2. Department of Cardiology, University Medical Center Mainz, Johannes Gutenberg-University, Germany (A.P.B.).
3. Cardiac Electrophysiology and Pacing, Division of Cardiology, Department of Medicine (G.A., J.G.A.-V., S.D., J.D.R., J.A.W., J.S.H.), Hamilton, ON, Canada.
4. Royal Victoria Hospital, Barrie, ON, Canada (B.D.).
5. Division of Cardiology, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa (V.M.).