The Trend Of Autonomic Nervous System Activity In The Process Of Sleep Apnea

Objective: To study and discuss the respective characteristic trends of autonomicnervous system (ANS) activity in the processes of obstructive sleep apnea (OA) andcentral sleep apnea (CA). And to compare their similarities and differences.Methods:30patients with diagnosed obstructive sleep apnea syndrome bypolysomnograph were enrolled in the study. The RR intervals and relative data wereextracted during the apnea, as well as a15-second period before and after the apnea.RR data during a one-minute period with stable respiration were also extracted. Thenthe different trends of heart rate variability (HRV) for OA and CA were analysed andcompared.Results: HRV parameters differed significantly in the process of OA in that,RR-Mean value, RR-SD and RR-rMSSD shifted slower level during OA, but returnedto a much more higher level after OA. It suggested that RR interval was much slowerduring OA with less variability. The HRV parameters showed no obvious changing inthe process of CA. The HRV parameters were increased in the OA and CA，then theywere decreased after the OA and CA. The HRV parameters in stable period wascompared with the corresponding parameters in OA and CA, the RR-Mean andRR-rMSSD values were lower in OA and CA, but were higher in the stable periods.At last, significant positive correlation between AHI and RR-Mean was observed.Conclusions: Different trends of ANS activity could be suggested during theprocessed of OA and CA. In other words, the sympathetic activity shifted to higherlevel during OA, and returned to a much lower level after it.. In comparison, CApresented no significant changed of ANS activity.