1. Department of Emergency Medicine, University “La Sapienza,” Rome Italy
2. Department of Cardiology, Children's Hospital, Boston, Massachusetts, USA
3. Department of Pediatrics, Harvard Medical School, Division of Pediatric Cardiology Boston, Massachusetts, USA
4. Division of Pediatric Cardiology, University of Rochester Medical Center and Strong Children's Hospital, Rochester, New York, USA
5. Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA