1. Division of Pediatric Cardiology Nationwide Children’s Hospital Columbus OH USA
2. University of North Carolina Children’s Hospital Chapel Hill NC USA
3. Morgan Stanley Children's Hospital of New York Presbyterian Columbia University Irving Medical Center New York New York New York USA
4. Ann and Robert H. Lurie Children’s Hospital of Chicago Chicago IL USA
5. Children’s Healthcare of Atlanta Atlanta GA USA
6. Johns Hopkins Children’s Center Baltimore MD USA
7. Children’s Hospital Los Angeles Los Angeles CA USA