Robert E. Shaddy, MD, is Chief, Division of Cardiology, Children's Hospital of Philadelphia; and Professor of Pediatrics, University of Pennsylvania School of Medicine.Marie M. Gleason, MD, is Associate Chief and Director of Outpatient and Community Cardiology, Children's Hospital of Philadelphia; and Professor of Pediatrics, University of Pennsylvania School of Medicine.Jack Rychik, MD, is Medical Director of The Fetal Heart Program and Associate Chief for Academic Affairs, Children's Hospital of Philadelphia; and Professor of Pediatrics, University of Pennsylvania School of Medicine.