HEART acceleration accompanying the act of swallowing in adults and experimental animals has been known for many years.1-5 In newborn infants, however, deceleration of the heart is a common and unique cardiovascular response to suckle feeding. Phillips et al6 have recently reported this response in premature infants. The following paper records observations on the frequency and reproducibility of this cardiac deceleration response in infancy in 158 cases, some factors in its elicitation, and its relationship to change in respiration during feeding. These investigations were commenced after this phenomenon of bradycardia at feeding was noted by one of us (N.J.C.) during the routine examination of newborn infants.
Since it was observed that changes in heart rate on bottle feeding occurred simultaneously with swallowing, the terms, suckle feeding and swallowing, are generally used without distinction in this paper.
Subjects and Methods
A total of 135 unselected healthy infants from the