Captopril in heart failure secondary to a left to right shunt.

Captopril was used in 20 infants aged less than 1 year with heart failure secondary to defects with predominantly a left to right shunt that was poorly controlled with digoxin and diuretics. Total daily dose of captopril ranged from 0.88 to 2.5 mg/kg (mean 1.3 mg/kg) in three divided doses. Improvement in the control of heart failure was seen mainly as an increase in the rate of weight gain from a mean of 48 g/week before treatment to 102 g/week on treatment and a decrease in the mean respiratory rate from 68 breaths/minute to 60 breaths/minute. Side effects were seen in four patients--two with asymptomatic mild hypotension, one with renal insufficiency which improved with a reduction in dose, and one with severe oliguria progressing to renal failure. Significant changes in plasma electrolyte concentration did not occur except in the infant who developed acute renal failure.