1. Cardiology Unit, Azienda Ospedaliero-Universitaria di Ferrara, 44124 Cona, Italy
2. Cardiology Department, Policlinico San Marco, 24046 Zingonia, Italy
3. Cardiology Department, Istituto Clinico S. Anna, 25127 Brescia, Italy
4. Cardiology Department, Clinica San Carlo, 20037 Paderno Dugnano, Italy
5. Cardiology Department, Istituto Clinico Sant’Ambrogio, 20161 Milano, Italy
6. Cardiology Department, Ospedale San Filippo e Nicola, 67051 Avezzano, Italy