The congenital heart diseases associated with Down's syndrome children attending the department of pediatrics at Gunma Children's Medical Center were studied. Of 66 Down's syndrome children consulting us for cardiac examination, 58 were associated with congenital heart disease. We diagnosed congenital heart disease associated with Down's syndrome as early as possible in infancy, understood the severity of the disease, and decided to undertake long-term management. In long-term management, checking of pulmonary hypertension is important due to it's effect on the long-term prognosis of these children. We studied changes in pulmonary vascular resistance during torazoline, dopamine or isoproterenol infusion. Consequently, we consider that this may be a useful indicator in the management of pulmonary hypertension. In association with Down's syndrome, end cardial cushion defect is most common in America and Europe, but in Japan it is being replaced by ventricular septal defect. In our hospital, a similar trend was observed.
