1. Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH.
2. Florida Hospital for Children, Orlando, FL.
3. Children's National Medical Center, Washington, DC.
4. Department of General Pediatrics, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE.
5. Helen DeVos Children's Hospital, Grand Rapids, MI.
6. UH Rainbow Babies and Children's Hospital, Cleveland, OH.
7. Department of Pediatrics, University of Illinois College of Medicine at Peoria, Peoria, IL.
8. Cincinnati Children's Hospital Medical Center, Cincinnati, OH.
9. Department of Pediatrics, University of Michigan, Ann Arbor, MI.