title: Developmental patterns of heart rate and variability in prematurely-born infants with apnea of prematurity.
abstract: At equivalent post-conceptional ages, prematurely-born infants have higher heart rates and reduced heart rate variability, relative to full-term neonates. Premature birth might exert long-lasting effects on central and peripheral mechanisms that control cardiovascular activity. We assessed development of heart rate and heart rate variability in symptomatic preterm infants up to 6 months of age. Fifty 6.5-h evening recordings of EKG and breathing were obtained from prematurely-born infants (gestational ages: 24-35 weeks). Cardiac R-R intervals were captured with a resolution of +/- 0.5 msec. One-min epochs were selected from three periods of regular respiration in recordings from premature infants and 72 recordings of full-term infants at comparable post-conceptional ages. Mean heart rate and heart rate variability were determined for each recording. At 40 weeks post-conception, prematurely-born infants with apnea of prematurity showed higher heart rates and reduced heart rate variability than did full-term neonates. These differences between premature and full-term infants persisted throughout the next 6 months in those infants born prior to 30 weeks gestation, and in those infants born at 30-35 weeks who experienced respiratory distress syndrome (RDS) during the neonatal period. The findings suggest that premature delivery, or complications thereof, exerts long-lasting effects on cardiac control.
authors.affiliation: Southwest SIDS Research Institute, Brazosport Memorial Hospital, Lake Jackson, TX 77566, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Henslee
authors.forename: V L
authors.initials: VL
authors.lastname: Schechtman
authors.forename: M Y
authors.initials: MY
authors.lastname: Lee
authors.forename: R M
authors.initials: RM
authors.lastname: Harper
mesh_terms: D000375:Aging; D001049:Apnea / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D005865:Gestational Age; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D012119:Respiration; D012127:Respiratory Distress Syndrome, Newborn / Q000503:physiopathology