Short-term hemodynamic effects of captopril in infants with congestive heart failure

R. E. Shaddy, D. F. Teitel and C. Brett
Department of Pediatrics, University of California, San Francisco.

We studied the short-term hemodynamic effects of captopril in ten infants with congestive heart failure secondary to large left-to-right shunts who were refractory to routine medical management with digoxin and diuretics. During cardiac catheterization, captopril (0.5 to 1.0 mg/kg) was administered by nasogastric tube. For the entire group, mean systemic blood flow, pulmonary blood flow, and the pulmonary-to-systemic blood flow ratio did not change significantly after captopril administration. However, in the seven patients in whom baseline systemic vascular resistance was greater than 20 U/m2, captopril decreased the pulmonary-to-systemic blood flow ratio. In contrast, in the three patients in whom baseline systemic vascular resistance was less than 20 U/m2, captopril increased the pulmonary-to-systemic blood flow ratio. We conclude that captopril acutely decreases the pulmonary-to-systemic blood flow ratio in infants with large left-to-right shunts who have elevated systemic vascular resistance. Renal function must be monitored closely when using captopril.