1. Cardiology Department, Attikon University Hospital, National and Kapodistrian University of Athens Medical School, Rimini 1, Chaidari, 124 62 Athens, Greece
2. Department of Cardiology, Essex Cardiothoracic Centre, Basildon SS16 5NL, UK
3. Department of Cardiology, Mitera General Hospital, 151 23 Athens, Greece
4. Medical Technology Research Centre, Anglia Ruskin School of Medicine, Chelmsford CM1 1SQ, UK
5. Department of Cardiology, University Hospital of Patras, 265 04 Patras, Greece