[1] Queens Univ, Div Cardiol, Kingston, ON, Canada
[2] Montefiore Med Ctr, Div Cardiol, Bronx, NY USA
[3] Univ CES, Arrhythmia Heart Inst, Dept Med, Div Cardiol,Clin Amer, Medellin, Colombia
[4] Univ Toronto, Southlake Reg Hlth Ctr, Div Cardiol, Toronto, ON, Canada
[5] Grandview Med Ctr, Alabama Cardiovasc Grp, Birmingham, AL USA
[6] Harvard Med Sch, Brigham & Womens Hosp, Cardiac Arrhythmia Ctr, Div Cardiovasc Med, Boston, MA USA