Our findings suggest that vagal modulation of the heart remains relatively normal in pediatric subjects with OSAS. However, baseline cardiovascular sympathetic activity is elevated, and reactivity to autonomic challenges is impaired.

Exposure to RA over durations approximating an hour produces cumulative effects on autonomic control that are subtle and can only be detected when advanced signal processing methods are employed. More specifically, the increases in ABR and RSA gains that accompany increasing sleep depth in normal sleep are prevented from occurring.

No abstract

Adults with obstructive sleep apnea syndrome (OSAS) are known to have impaired autonomic function but the corresponding effects in children appear to be more subtle. Model-based analysis of the cardiovascular response to cold face test (CFT) was used to quantify daytime autonomic dysfunction. The increase in transfer gain between respiration and RRI was not different between controls and OSAS. However, the transfer gain between "surrogate cardiac output" (pulse pressure+R-R interval) and systolic blood pressure (SBP) and the transfer gain between cardiac output and SBP both increased significantly in controls but not in OSAS during CFT. These findings suggest that the parasympathetic function remains relatively normal in pediatric OSAS, but cardiovascular sympathetic reactivity is impaired.