Studies On The Lorenz Plot And Heart Rate Variability In Patients With Sleep Apnea Hypopnea Syndrome

Objective:To study the differences of Lorenz plot nonlinear indicators SD1,SD2 and the correlation with time-domain and frequency-domain indicators of heart rate variability in patients with sleep apnea hypopnea syndrome analysis,The preliminary screening of sleep apnea hypopnea syndrome was conducted by using Lorenz plot and heart rate variability index.Method:1.A portable sleep apnea monitor was used to monitor 177 suspected sleep apnea patients for at least 7 hours of sleep all night,at the same time a 24-hour dynamic electrocardiogram was performed.According to the results of sleep monitoring,groups are organized:AHI?5/hour is SAHS group;AHI<5/hour is the normal group.Set 23:00-06:00 of the test period recorded by Holter as the sleep period,and the rest of the time(the time that was well recorded for more than six consecutive hours in the non-sleep period)as the waking time,to record the nonlinear indicators SD1 and SD2 values of Lorenz plot;HRV time domain indicators SDNN,SDANN,rmssd,pnn50 values;frequency domain indicators TP,VLF,LF,HF,LF/HF values for sleep,awake,and total test time respectively.Conduct intergroup statistical analysis and correlation analysis of the resulting data.2.To select the suitable indexes by using Youden index and ROC curve,and with the application of integral method and single factor comparison in initial screening of sleep apnea.Results:1.There is correlation between the nonlinear index of Lorenz plot and the time-domain frequency index of heart rate variability,and the heart rate variability can be assessed using the Lorenz plot.2.There were significant differences in the day and night variation of Lorenz plot in patients with sleep apnea hypopnea syndrome(SAHS)3.Suspicious patients with sleep apnea hypopnea syndrome(SAHS)can be screened by means of Lorenz plot combined with time-domain and frequency-domain indices of heart rate variabilit.Conclusion:In patients with sleep apnea hypopnea syndrome(SAHS),there is a correlation between the Lorenz plot nonlinear indicators SD1,SD2 and the temporal and frequency domain indicators of heart rate variability(HRV).The autonomic nerve function of patients with SAHS was disordered,and there was significant difference between day and night.Using the Lorenz plot and the time-domain and frequency-domain indicators,the suspicious patients with sleep apnea hypopnea syndrome(SAHS)can be initially screened,and the Lorenz plot has the advantages of being more intuitive and simple.