Beat-to-beat variation of the heart rate in children with allergic asthma

Area of Science:

• Pediatric Allergy
• Cardiology
• Autonomic Nervous System Function

Background:

• Allergic asthma is a common condition in children.
• Autonomic nervous system imbalances, particularly increased cholinergic tone, have been implicated in asthma.
• Heart rate variability (HRV) is a non-invasive measure of autonomic function.

Purpose of the Study:

• To quantitatively assess beat-to-beat heart rate variation in allergic asthmatic children.
• To compare heart rate variability between allergic asthmatic children, allergic non-asthmatic children, and non-allergic children.
• To investigate the relationship between allergic status and cholinergic tone.

Main Methods:

• Heart rate variability was measured using the coefficient of variation of the R-R interval (CVR-R).
• Participants included 53 allergic asthmatic children, 47 allergic children without asthma, and 284 non-allergic children.
• Statistical analysis was performed to compare mean CVR-R values between groups.

Main Results:

• Allergic children, both with and without asthma, demonstrated significantly higher mean CVR-R values compared to non-allergic children (p<0.01 and p<0.001, respectively).
• The mean CVR-R was 7.08 ± 1.87 for allergic asthmatic children, 7.54 ± 2.40 for allergic non-asthmatic children, and 6.32 ± 1.88 for non-allergic children.
• These findings indicate elevated cholinergic tone in allergic individuals.

Conclusions:

• Increased cholinergic tone is associated with the allergic state, independent of asthma.
• Heart rate variability analysis can help elucidate autonomic dysfunction in allergic conditions.
• The allergic state itself, not solely allergic asthma, contributes to altered autonomic balance.