[Hemodynamic studies of nifedipine (Adalat) in pulmonary hypertension in childhood].

Under long-term oral treatment with nifedipine (N) 2 of 3 patients (2 children with VSD and Eisenmenger, 1 patient with Truncus I after corrective surgery) showed a remarkable improvement in exercise tolerance and reduction in the total pulmonary resistance. Therefore a single-dose testing with N was performed in 9 patients aged 2 to 20 years with primary pulmonary hypertension (n = 2), secondary pulmonary hypertension because of congenital heart disease with intracardiac shunts (n = 6) and after correction of Truncus Type I (n = 1). Before and after the injection of 0.5 mcg/kg of N into the main pulmonary artery, pulmonary artery pressure, cardiac output and systolic blood pressure were measured at 1 minute intervals during right heart catheterization. The maximal reaction occurred 3 to 4 minutes after the injection. The total pulmonary vascular resistance decreased significantly from 2684.2 +/- 1829.2 to 1300.2 +/- 1117.0 dyn.sec.cm-5.m2 (p less than 0.025), the cardiac index increased significantly from 3.1 +/- 1.65 to 5.73 +/- 1.95 l/min.m2 (p less than 0.01) concomitantly with a mild reduction in the mean pulmonary artery pressure. No significant change in heart rate and systolic blood pressure was seen; no side effects were observed. 4 of the 5 patients with the highest pulmonary vascular resistance showed the best positive reactions. Therefore these 9 patients may benefit from a long-term oral treatment with nifedipine.