Effect Of Premature Ventricular Contractions Burdens And Heart Rate Variability On Heart Failure

Background: Heart rate was regulated by the balance between sympathetic and vagal nerves and the circadian rhythm.Heart rate variability(HRV)in patients with heart failure declined.The number of premature ventricular contractions(PVCs)was related to changes in HRV,while effect on cardiac function were not well understood.Objective: By analyzing the relationship between the burden of PVCs and HRV,and exploring the predictive value of the burden of PVCs and HRV on heart failure.Methods :A total of 190 eligible hospitalized patients(age,59.54±16.28 years,91 females)were enrolled.24-hour Holter electrocardiogram(ECG)was used to evaluate the burden of PVCs and HRV.Echocardiography,used to measure Left ventricular ejection fraction(LVEF),and NT-pro BNP were used to assess left ventricular function.According to whether combined with organic cardiopathy,it was divided into 100 cases of idiopathic PVC group and a merger 90 patients with PVC of organic cardiopathy.And then,they were divided into 3 subgroups according to different burdens:low load group(≦10%),medium load group(10%~20%),high load group(>20%).Compared the differences of patient characteristics,24-h HRV in both the time domain(SDNN,SDANN,RMSSD and p NN50)and the frequency domain(low-frequency power(LF),high-frequency power(HF),and low-frequency/high-frequency(LF/HF)),treatment among three subgroups。Multivariate logistic regression and ROC curves were used to analyze the predictors of heart failure in HRV in patients with PVCs.Results: There was a statistically significant difference in HRV between idiopathic PVC group and PVC with organic heart disease group(p<0.05).With the increase of PVC burdens,SDANN decreased,while r-MSSD and p NN50 increased,and the LF,HF and LF/HF showed opposite trends in the idiopathic PVC group.It suggested that the sympathetic and vagal nerves were imbalanced in heart rate regulation and the excitatory activity was enhanced.However,the changes of SDNN,SDNN Index,SDANN,r-MSSD and p NN50 in the PVCs group with organic heart disease were not obvious,and the HF,LF/HF showed the same changing trend.With the increase in the burden of PVC,the LVEF decreased in the idiopathic PVC group(p<0.001),but there was no significant change in LVEF when combined with organic heart disease(p=0.861).HRV is a predictor of PVCs with heart failure.r-MSSD(OR: 1.015,95% CI: 1.002-1.029,P =0.022),LF/HF(OR: 1.355,95% CI: 1.020-1.800,P = 0.036)were predictors in Idiopathic PVC group;SDNN(OR: 1.015,95% CI:1.000-1.030,P = 0.043),r-MSSD(OR: 0.998,95% CI: 0.978-0.999,P =0.027)were predictors in PVC with organic cardiopathy group.Conclusions: PVC burdens was related to HRV.HRV in 24-hour Holter electrocardiogram and PVC burdens had certain predictive value for heart failure events.