1 Arrhythmia Service, Division of Cardiology, University of Ottawa Heart Institute, 40 Ruskin Street, H-1285A, Ottawa, ON, K1Y 4W7, Canada.
2 Department of Cardiac Sciences, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
3 The Section of Cardiac Electrophysiology, Cardiovascular Division, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
4 Arrhythmia Service, Division of Cardiology, University of Ottawa Heart Institute, 40 Ruskin Street, H-1285A, Ottawa, ON, K1Y 4W7, Canada. msadek@ottawaheart.ca.