1. Pacing and Electrophysiology Unit, Cardiology Department Coimbra's Hospital and University Center Coimbra Portugal
2. Cardiology Department Hospital da Luz Arrábida V. N. Gaia Portugal
3. Cardiology Department University Hospital Center of São João Porto Portugal
4. Cardiology Department Vila Nova de Gaia and Espinho Hospital Center V. N. Gaia Portugal
5. Cardiology Department Clinique Saint Pierre Perpignan France
6. ICBR, Faculty of Medicine University of Coimbra Coimbra Portugal