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Cardiovascular autonomic regulation in preterm infants: the effect of atropine

Peter Andriessen1, Ben J A Janssen, Ralph C M Berendsen

  • 1Máxima Medical Center, Neonatal Intensive Care Unit, Veldhoven, P.O. Box 7777, 5500 MB, The Netherlands. P.Andriessen@mmc.nl

Pediatric Research
|October 8, 2004
PubMed

Insights

Atropine significantly alters heart rate (HR) and blood pressure (BP) variability in preterm infants. This suggests parasympathetic control is crucial for cardiovascular regulation in neonates, even during respiratory distress.

Area of Science:

  • Neonatal physiology
  • Autonomic nervous system function
  • Cardiovascular research

Background:

  • Cardiovascular autonomic control is critical in preterm infants.
  • Understanding autonomic regulation aids in managing cardiorespiratory instability.
  • Preterm infants often experience respiratory insufficiency, impacting autonomic function.

Purpose of the Study:

  • To investigate the effects of atropine on heart rate (HR) and blood pressure (BP) variability in preterm infants.
  • To assess baroreceptor reflex (BR) functioning before and after atropine administration.
  • To determine the role of parasympathetic control in cardiovascular regulation in this population.

Main Methods:

  • Assessed 12 preterm infants (26-32 wk gestation) before intubation.
  • Administered atropine sulfate (0.01 mg/kg).
  • Utilized spectral power analysis of R-R interval and systolic BP (SBP) series (LF and HF bands) and transfer function analysis for BR assessment.

Main Results:

  • Atropine increased steady-state HR by 12% (p < 0.01) but did not change SBP.
  • Total spectral power of R-R interval decreased 6-fold, primarily in the LF band (16-fold reduction).
  • Total spectral power of SBP series increased by 25% (p < 0.05), with increased HF power. Baroreceptor reflex sensitivity (LF transfer gain) significantly decreased post-atropine.

Conclusions:

  • Atropine modulates HR and BP variability in preterm infants, even those in respiratory distress.
  • Parasympathetic control, mediated by the baroreceptor reflex, plays a significant role in cardiovascular regulation in preterm neonates.
  • Findings highlight the importance of autonomic nervous system assessment in neonatal care.

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