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Abnormal heart rate response to hypercapnia in boys with an apparent life-threatening event

A Edner1, M Ericson, J Milerad

  • 1Department of Woman & Child, Karolinska Institute, Stockholm, Sweden. Ann.Edner@kbh.ki.se

Acta Paediatrica (Oslo, Norway : 1992)
|February 13, 2003
PubMed

Insights

Infants with apparent life-threatening events (ALTE) show altered heart rate variability when exposed to increased carbon dioxide (CO2). This suggests autonomic dysfunction may contribute to Sudden Infant Death Syndrome (SIDS) risk, especially in boys.

Area of Science:

  • Pediatric Cardiology
  • Autonomic Nervous System Function
  • Sudden Infant Death Syndrome (SIDS) Research

Background:

  • Infants at risk for Sudden Infant Death Syndrome (SIDS) may exhibit subtle autonomic dysregulation.
  • Carbon dioxide (CO2) challenges can reveal underlying cardiovascular control mechanisms.

Purpose of the Study:

  • To investigate cardiac variability responses to CO2 in infants with a history of apparent life-threatening events (ALTE).
  • To compare these responses with those of healthy control infants.

Main Methods:

  • Cardiac rate variability was assessed before, during, and after a CO2 challenge.
  • The study included 41 infants with ALTE and 41 matched controls.

Main Results:

  • ALTE infants demonstrated a significantly greater increase in R-R intervals (heart rate decrease) during CO2 breathing compared to controls (45.1% vs. 41.4%).
  • This difference was primarily driven by the responses observed in ALTE boys.

Conclusions:

  • ALTE infants, particularly boys, exhibit signs of autonomic dysfunction when exposed to CO2.
  • This dysfunction may involve reduced sympathetic stimulation and/or impaired vagal withdrawal.
  • Findings may offer insights into cardiovascular mechanisms contributing to SIDS.
Abstract

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