1. Electrophysiology Unit, Cardiovascular Division, Hospital del Mar. Passeig Marítim de la Barceloneta , 25-29. Barcelona 08003 Spain
2. Electrophysiology Unit, Cardiology Department, Hospital Universitari Germans Trias i Pujol , Badalona , Spain
3. Arrhythmias Unit, Heart Disease Institute, Bellvitge University Hospital , Barcelona , Spain
4. Department of Cardiology, Unità Operativa di Cardiologia, Azienda Ospedaliera S. Maria Nuova , Reggio Emilia 42123 , Italy
5. Arrhythmia Unit, Cardiology Department, Hospital Universitario Clínico San Cecilio , Granada , Spain
6. Arrhythmia Unit, Hospital Universitario Virgen de las Nieves , Granada , Spain
7. Heart Diseases Biomedical Research Group, Hospital del Mar Medical Research Institute (IMIM) , Barcelona , Spain
8. Electrophysiology Unit, Department of Cardiology, Hospital de la Santa Creu i Sant Pau , Barcelona , Spain
9. Abbott Electrophysioloy , Chicago, IL , USA