1. Department of Cardiology, Patras University Hospital, Rio, Patras, Greece
2. Department of Cardiology, “Agia Olga” General Hospital, Athens, Greece
3. Department of Cardiology, “KAT” Hospital, Athens, Greece
4. Department of Cardiology, “AHEPA” University Hospital, Thessaloniki, Greece
5. Department of Cardiology, “Tzaneio” General Hospital, Piraeus, Greece
6. Department of Cardiology, “Hippokration” University Hospital, Athens, Greece
7. Department of Cardiology, “Castle Hill” Hospital, Cottingham, UK
8. Department of Cardiology, “Eurokliniki,” Athens, Greece