1. Divisione Medica ‘Brera’ e Reumatologia, Ospedale Niguarda Ca’ Granda, Milan, Italy,
2. Children’s Hospital, Uppsala University, Uppsala, Sweden
3. St. Luke’s - Roosevelt Hospital Center, New York
4. Babies’ and Children’s Hospital, Columbia Presbyterian Medical Centre, New York, USA
5. Cardiologia Pediatrica, Ospedale Niguarda Ca’ Granda, Milan, Italy
6. U.O. Elettrofisiologia-Elettrostimolazione, Istituto Clinico Humanitas, Rozzano, Milan, Italy
7. Abteilung fur Pediatrische Kardiologie, Universitatsklinik fur Kinder und Jugendheilkunde, Graz, Austria
8. Servizio di Cardiologia, Ospedale dei Bambini ‘V. Buzzi’, Milan, Italy
9. Hospital for Joint Diseases, New York University School of Medicine, New York