Evaluation Of Autonomic Function In Patients With Sleep Apnea-hypopnea Syndrome By Dynamic Electrocardiogram

Objective:To evaluate the autonomic nerve function injury in patients with sleep apnea-hypopnea syndrome(SAHS)by dynamic electrocardiogram analysis,and to determine the changes of each index in SAHS patients.Method:Sleep monitoring(PSG or portable sleep detector)and dynamic electrocardiogram were performed in 244 patients with suspected SAHS during the whole night(>7 h).According to the results of PSG,they were divided into three groups:normal group(sleep apnea hypopnea index AHI<5,n=40),mild to moderate group(5?AHI<30,n=93),severe group(AHI>30,n=111).General information of patients?AHI?minimum pulse oxygen saturation and ECG parameters(heart rate variability(HRV),heart rate turbulence(HRT),deceleration capacity of heart rate(DC),acceleration capacity of heart rate(AC),heart rate deceleration runs(DRs),corrected QT interval(QTc))were analyzed and recorded.The data were analyzed by statistical analysis and correlation analysis.There was no significant difference in HRT?QTc?DRs among the three groups.Results:There were significant differences in total power,very low frequency and low frequency among the three groups(P<0.05).During the whole day,there were significant differences in DC and AC values among the three groups(P<0.05).Further processing of ECG data(diurnal difference/full day),PNN50?total power?very low frequency?high frequency?DC and AC values were significantly different among the three groups(P<0.05).SDN-N?rMSSD?pNN50?total power?very low frequency?high frequency?DC were weakly negatively correlated with AHI(P<0.05).Conclusion:SAHS patients may had autonomic nerve function impairment,and there were differences between daytime and nighttime,especially in daytime.DC?AC and HRV frequency domain(total power,very low frequency,low frequency)have more obvious difference than other indexes.It is suitable for evaluating autonomic nervous function in patients with SAHS.The correlation between HRV?DC(diurnal difference/full day)and AHI was stronger,and there was more correlation between autonomic nerve injury and severe condition of SAHS patients.The diurnal difference/full day value might be used as a criterion for screening SAHS.