1. Department of Experimental and Clinical Medicine, University of Florence, Meyer University Children Hospital and Careggi University Hospital , Viale Pieraccini 24, 50139 Florence , Italy
2. Division of Cardiology and The CardioVascular Center, Tufts Medical Center, and the Tufts University School of Medicine , 800 Washington St, Boston, MA 02111 , USA
3. Cardiology Department, Hospital San Donato , Via Pietro Nenni, 20 - 52100 Arezzo , Italy
4. Cardiology Centre, University of Ferrara , Via Fossato di Mortara, 64/B - 44121 Ferrara , Italy
5. Maria Cecilia Hospital, GVM Care & Research , Via Corriera, 1, 48033 Cotignola, Emilia-Romagna , Italy