1. ABC Medical Center I.A.P, Cardiovascular Division, Mexico City, Mexico.
2. National Institute of Cardiology "Ignacio Chavez", Echocardiography in Out-Patient Clinic, Immunology Department, Embryology Department, Mexico City, Mexico.
3. The John Langdon Down Foundation, A.C, Pediatric Department, Mexico City, Mexico.
4. St. Francis Hospital, Cardiac Imaging, New York, USA.
5. Massachusetts General Hospital, Interpreters Service, Boston, USA.