Systolic Time Intervals in Infants with Congestive Heart Failure

Using the apexcardiogram as a time reference for opening and closure of the aortic valve, systolic time intervals (STI) in infants were determined in 150 normal infants ranging in age from 1 day to 1 year. Thirty infants with congestive heart failure secondary to a variety of congenital and acquired heart diseases were studied in a similar manner for comparison. The data revealed that heart failure in the infant is not marked by any one pattern of STI. In specific disease entities associated with congestive heart failure, the STI appear to be consistent. In infants with congestive heart failure due to congenital heart disease, the STI do not correspond with values reported in the adult with hypertensive or arteriosclerotic disease. The differences are explained by viewing STI in infants primarily a function of hemodynamic alterations dictated by an underlying cardiovascular anomaly rather than a result of a primary myocardial derangement. The findings in the infant with chronic heart failure due to primary myocardial disease tend to parallel data previously reported in the adult with arteriosclerotic disease and chronic heart failure.