André d'Avila1, Marco F Vidal Melo2, Renato D Lopes3. 1. Serviço de Arritmia Cardíaca, Hospital SOS Cardio, Florianópolis, SC - Brasil. 2. Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA - USA. 3. Division of Cardiology, Duke Clinical Research Institute, Duke University School of Medicine, Durham, NC - USA.