1. Department of Cardiology, Hospital de Sao Paulo, Rua Napoleao de Barros, 715-Vila Clementino Sao Paulo, SP-CEP: 04024002, Sao Paulo, Brasil
2. Cardiac Electrophysiology and Pacing, Kingston General Hospital K7L 2V7, Queen's University, Kingston, Ontario, Canada
3. Heart Failure Unit, Hospital Universitari Germans Trias i Pujol, Carretera del Canyet, s/n, 08916 Badalona, Barcelona, Spain
4. Cardio Vascular Research Center, Catalan Institute of Cardiovascular Sciences, St. Pau Hospital, C/Sant Antoni Ma Claret, 167, 08025 Barcelona, Spain