[1] St Michaels Hosp, Div Cardiol, Toronto, ON M5B 1W8, Canada
[2] Montreal Heart Inst, Div Cardiol, Montreal, PQ H1T 1C8, Canada
[3] St Pauls Hosp, Div Cardiol, Vancouver, BC V6Z 1Y6, Canada
[4] Sunnybrook & Womens Coll Hlth Sci Ctr, Div Cardiol, Toronto, ON, Canada
[5] Univ Calgary, Dept Cardiac Sci, Libin Cardiovasc Inst Alberta, Calgary, AB, Canada
[6] London Hlth Sci Ctr, Div Cardiol, London, ON, Canada
[7] Univ Western Ontario, London, ON, Canada