[Hemodynamic effects of an alpha-blocking vasodilator in cardiac insufficiency caused by left-right shunt in children].

The acute haemodynamic effects of an alpha-blocking vasodilator, nicergoline, observed during cardiac catheterisation were studied in 9 babies and 1 infant (mean age 11 months) with severe cardiac failure due to a large left-to-right interventricular shunt. Nicergoline was administered intravenously at a dose of 0.05 mg/kg/mn to 0.2 mg/kg/mn to lower mean systemic blood pressure by at least 10 mmHg. No significant changes in heart rate or in right and left atrial pressures were observed. On the other hand, mean systemic and pulmonary arterial pressures fell by 16% (p less than 0.001) and 13% (p less than 0.01) respectively. The ratio of pulmonary and systemic flow (Qp/Qs) decreased in 8 patients by an average of 21% (p less than 0.002). This fall was accompanied by a parallel reduction in oxygen concentrations of pulmonary arterial blood (16%) compared with mixed venous blood. However, the Qp/Qs ratio increased in the other 2 patients by over 50%. In the group of 8 patients in which the left-to-right shunt decreased, the ratio of pulmonary to systemic resistance (Rp/Rs) increased by 33% (p less than 0.002) whilst this value fell by 36% in the 2 patients in whom the volume of the shunt increased. There were no discriminatory parameters between the two groups with regards to age, pulmonary artery pressures, the volume of the shunt (Qp/Qs) or level of pulmonary resistances (Rp/Rs) to explain the variability of the therapeutic response on the left-to-right shunt.(ABSTRACT TRUNCATED AT 250 WORDS)