1. CNR, Istituto Fisiologia Clinica—Dipartimento di Biomedicina—Consiglio Nazionale delle Ricerche , CNR Research Campus, Via Moruzzi 1, Building C- Room 130, Pisa 56124 , Italy
2. Cardiology Division, Fatebenefratelli Hospital , Viale Principe di Napoli 14A, Benevento 82100 , Italy
3. Cardiodiagnosticos, Investigaciones Medicas Center , Pichincha 69, Buenos Aires C1082 , Argentina
4. Cardiology Department, San Luca Hospital , Via Guglielmo Lippi Francesconi, Località San Filippo, Lucca 55100 , Italy
5. Cardiology Department, Saint Petersburg State Pediatric Medical University , Litovkaya St 2, Saint Petersburg 194100 , Russian Federation
6. Centre of Cardiology and Angiology, Clinic of Cardiac and Vascular Diseases, Faculty of Medicine, Institute of Clinical Medicine , Vilnius LT-03101 , Lithuania
7. Paediatric Cardiology and Adult Congenital Heart Disease Program, Department of Cardio-Thoracic and Vascular Medicine IRCCS Azienda Ospedaliero-Universitaria di Bologna, Policlinico S. Orsola-Malpighi Hospital , Via Massarenti 9, Bologna 40138 , Italy
8. Department of Cardiovascular Medicine, Mayo Clinic , Rochester, MN 55905 , USA