1. Adult Congenital Heart Program, Department of Cardio-Thoracic and Vascular Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Italy (G.E.A.).
2. Divisions of Pediatrics and Cardiology, The Ohio State University, Columbus (J.P.C.).
3. Adult Congenital and Interventional Cardiology, Heart Center, Massachusetts General Hospital and Harvard Medical School, Boston (A.C.S.S.).