Relationship Of Lorenz-RR Scatter Plot With Heart Rate Variability With Heart Failure With Reduced Ejection Fraction

Objective: To study the relationship of Lorenz-RR scatter plot with heart rate variability and cardiac function classification of patients with heart failure with reduced ejection fraction(HFrEF).Methods: 128 patients with HFrEF admitted to the first hospital of Lanzhou University from August 2019 to February 2021 in the First Hospital of Lanzhou University as the HFrEF group,and HFrEF group were divided into three groups:NYHA class II subgroup(n=49),NYHA class III subgroup(n=45)and NYHA class IV subgroup(n=34),According to the New York heart function classification.in addition,A total of 100 healthy people were selected as the control group.The basic clinical data of all the investigators were collected,including the long axis L,short axis W,area A,long axis/short axis ratio L/W of Lorenz scatter Plot in 24-hour Holter and the shape of scatter plot,as well as the time-domain index(PNN50 、 SDNN,r MSSD,trigonometric index,SDANN,)and frequency-domain index(HF,LF).Clinical data,characteristics of Lorenz-RR scatter plot and HRV index were compared between the HFrEF group and the control group,the differences of NYHA cardiac function class II,III,IV subgroup were compared,and Pearson correlation analysis was used to analyse the correlation between Lorenz-RR scatter plot with HRV index and cardiac function classification in patients with HFrEF.Results:(1)Compared with the control group,L,W,A,L/W and SDNN,r MSSD,trigonometric index,PNN50,LF,SDANN,HF of the HFrEF group were remarkablely decreased.(2)The worse the cardiac function was,the more obvious the decrease of L,A,SDNN,SDANN,trigonometric index,HF PNN50,LF of Lorenz-RR scatter plot.(3)HFrEF group Lorenz-RR scatter plot was mostly torpedo shaped,short stick shaped and spindle shaped,while in control group it was mainly baseball shot.(4)Pearson correlation analyse results showed that L was significantly positively correlated with PNN50,triangular index,SDNN,LF,SDANN and HF of patients with HFrEF;W was positively correlated with r MSSD,PNN50,LFand HF;A was positively correlated with r MSSD,triangular index,SDNN,PNN50,LF,SDANN and HF;L/W was significantly positively correlated with SDANN,was significantly negatively correlated with r MSSD and PNN50.(5)Lorenz plot indexes L,W,A,L/Wwere positively correlated with LVEF and L,A,L/W,negatively correlated with NYHA cardiac function and NT-pro BNP(P<0.05).Conclusion:(1)The quantitative indexes of Lorenz-RR scatter plot of HFrEF patients decreased,and the worse the cardiac function,the more obvious the decrease of L and A.(2)Lorenz-RR scatter plot of HFrEF patients are torpedo-shaped,shuttleshaped,short rod-shaped and irregular.(3)There is a certain correlation with HRV index and cardiac function classification index.Therefore,Lorenz-RR scatter plot can directly and quantitatively analyze HRV of patients with HFrEF,and can also provide reference for evaluating cardiac fuction of patients.