1. Division of Cardiology; Queen's University; Kingston ON Canada
2. Instituto Cardiovascular de Buenos Aires; Buenos Aires Argentina
3. Division of Cardiology; Centro de Arritmias Cardíacas de la Ciudad Autónoma de Buenos Aires; Ramos Mejía Hospital; Buenos Aires Argentina
4. Hospital de la Santa Creu i Sant Pau; Cardiovascular Research Center; CSIC-ICCC; Barcelona Spain