1. School of Medicine,Heraklion University Hospital/University of Crete, Heraklion, Greece
2. Department of Cardiology, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
3. Department of Cardiology, Bichat Hospital, AP-HP, Paris, France
4. Department of Cardiology, Hippokration General Hospital, Athens, Greece
5. Meyer's Children Hospital IRCCS, Florence, Italy
6. Department of Clinical & Experimental Medicine, University of Florence, Florence, Italy