The Normal P-R Interval in Infants and Children

Abstract
The value of the P-R interval in the study and evaluation of treatment of rheumatic carditis, a disease predominantly of the younger ages, has prompted a re-examination of the normal P-R standards for infants and children. This study reports these data as obtained from 506 normal infants and children. The data reveal that both age and heart rate exert a significant influence on the P-R interval. The minimum, average, and maximum values are given as related to different ages and different heart rates.