Inhaled nitric oxide to test the vasodilator capacity of the pulmonary vascular bed in children with long-standing pulmonary hypertension and congenital heart disease.

Nitric oxide-induced vasodilator capacity greatly varies among children with pulmonary hypertension and elevated vascular resistance. The decline of this selective response seems to parallel the progression of established vascular disease and thus may be helpful for the selection of patients for operation.