1. Department of Cardiology, Boston Children’s Hospital and Department of Pediatrics, Harvard Medical School, MA (B.Z., M.L., L.A.S., D.W.B.).
2. Section of Cardiology, Department of Pediatrics, Children’s Hospital Colorado, University of Colorado, Denver (E.M.B.).
3. Division of Cardiology, Department of Pediatrics and Communicable Diseases, C.S. Mott Children’s Hospital, University of Michigan, Ann Arbor (K.E.B.).
4. Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, OH (G.D.H.).
5. Division of Cardiology, Department of Pediatrics, Seattle Children’s Hospital, University of Washington, WA (N.M.P.).