BACKGROUND: Clinical observations suggest the immaturity of the neonate's ability to respond appropriately to cardio-respiratory challenges and tilt test could help in detecting autonomic dysfunction in neonates.MATERIAL/METHODS: Heart rate (HR) responses following a 45 degrees head-up tilt during sleep were measured within the first week of adjusted age in 7 healthy full-term neonates, 7 healthy preterm infants and 5 neonates with abstinence syndrome.RESULTS: The tilt and the return to the horizontal position generally provoked a sustained or transient tachycardia, or a flat response in healthy full-term neonates and in preterm neonates, but a sustained or transient bradycardia in neonates with abstinence syndrome.CONCLUSIONS: When compared to previous studies in older infants, our data point to the immaturity of the neonate's ability to respond appropriately to cardio-respiratory challenges. No difference is noted between full-term and preterm neonates. The altered HR response in neonates with abstinence syndrome suggests an autonomic dysregulation in this group.
Bradycardia Female