Infants with a history of an apparent life-threatening event exhibited a significantly greater increase in R-R intervals during CO2 breathing compared to matched controls (45.1% vs. 41.4%; p=0.005).
Case-Control (n=82)
Absolute Event Rate: 45.1% vs 41.4%
p-value: p=0.005
AIM: To determine instantaneous cardiac variability responses to increased carbon dioxide (CO2) during quiet sleep in infants who may be at risk for the Sudden Infant Death syndrome (SIDS). METHODS: The cardiac rate variability before, during and after a CO2 challenge was examined in 41 infants who had experienced an apparent life-threatening event (ALTE) and 41 gender- and age-matched control infants. RESULTS: The ALTE infants responded to CO2 breathing with a significant increase in R-R intervals, i.e. decreases in heart rate, compared to the controls (45.1% increase in R-R intervals vs. 41.4%; p = 0.005). The differences between ALTE infants and controls depended primarily on the boys' responses. CONCLUSION: ALTE infants, particularly ALTE boys, have an autonomic dysfunction-lower sympathetic stimulation and/or inhibited vagal withdrawal when stressed with CO2. The outcome might provide clues to the mechanisms underlying the cardiovascular processes contributing to the terminal event in SIDS.
Edner et al. (Sun,) conducted a case-control in Apparent life-threatening event (ALTE) (n=82). History of an apparent life-threatening event (ALTE) vs. Gender- and age-matched control infants was evaluated on Increase in R-R intervals during CO2 breathing (p=0.005). Infants with a history of an apparent life-threatening event exhibited a significantly greater increase in R-R intervals during CO2 breathing compared to matched controls (45.1% vs. 41.4%; p=0.005).