Angiotensin converting enzyme activity in children with congenital heart disease.

Serum angiotensin converting enzyme (ACE) activity was determined in 46 children with congenital heart disease with normal and abnormal lung perfusion: (1) congenital heart disease with normal pulmonary blood flow (12 patients); (2) congenital heart disease with increased pulmonary blood flow (18 patients); (3) congenital heart disease with decreased pulmonary blood flow (16 patients). There was no significant difference in serum ACE activity between the three groups. In group 2 serum ACE activity had a tendency to correlate inversely with both mean pulmonary arterial pressure (r = -0.43; P less than or equal to 0.05) and pulmonary vascular resistance (r = -0.48; P = 0.05). No further correlations between serum ACE activity and age, serum electrolytes, creatinine nor other haemodynamic data could be established.