Edward P Walsh, MD, is Associate Chief of Cardiology for Clinical Affairs and Professor of Pediatrics at Boston Children's Hospital/Harvard Medical School in Boston. John E Mayer, MD, is Senior Associate in the Department of Cardiac Surgery at Boston Children's Hospital and Professor of Surgery at Harvard Medical School. David Brown, MD, is Director of the Pediatric Cardiology Fellowship Program and Associate Professor of Pediatrics in the Department of Cardiology at Boston Children's Hospital.