A Study On The Relationship Between Heart Rate Variability And Left Ventricular Ejection Fraction In Patients With Coronary Heart Disease

Objective:To investigate the correlation between heart rate variability(HRV)and left ventricular ejection fraction(LVEF)in patients with coronary heart disease(CHD),and to understand whether the heart rate variability can provide some help in the clinical diagnosis and treatment for the assessment of left ventricular systolic function in patients with CHD.Methods:We collected 429 patients from December 1,2017 to June 1,2018,who underwent coronary angiography(CAG)in the interventional lab,and hospitalized in the department of Chengdu Second People's Hospital.According to the results of CAG,patients were divided into the CHD group(n=143)and the non-CHD group(n=286).We collected parameters including:1)The general clinical data:gender,age,body mass index(BMI),smoking,drinking,history of hypertension,diabetes,hyperuricemia,peripheral arteriosclerosis and stroke,medical history(including angiotensin converting enzyme inhibitors(ACEI),angiotensin?receptor blockers(ARB),?receptor blockers,calcium channel blockers(CCB),anti-platelet aggregation drugs,hypoglycemic drugs,lipid-lowering drugs);2)Serum biochemical indexes:triglyceride(TG),high-density lipoprotein cholesterol(HDL-C),total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),creatinine(CREA),uric acid(UA);3)HRV indexes of 24h dynamic electrocardiogram:standard deviation of N-N intervals(SDNN)?standard deviation of averages of N-N intervals for 5 minutes(SDANN),mean of standard deviation of N-N intervals for 5 minutes(SDNN index),root meansquare of difference of successive N-N intervals(rMSSD),the percentage of the proportion of N-N intervals differing more than 50 ms in the total heartbeats(PNN50),low frequency(LF),low frequency to high frequency ratio(LF/HF),very low frequency(VLF),high frequency(HF);4)Left ventricular systolic function indexes:LVEF,stroke volume(SV),fractional shortening(FS).The baseline,HRV and left ventricular systolic function of the two groups were compared statistically.The correlation between HRV and LVEF was analyzed in CHD group.At the same time,the patients in CHD group were divided into normal LVEF group(n=205)and decreased LVEF group(n=81),HRV of the two groups were compared statistically.Results:(1)The comparison between the CHD group and non-CHD group:1)There was no significant difference in baseline data between the two groups(P>0.05),which was comparable;2)HRV comparison between the two groups:the HRV indicators of SDNN,SDNNindex,SDANN,rMSSD,PNN50,LF,LF/HF and VLF in the coronary heart disease group was lower than that in the non-coronary heart disease group,and there were significant differences between two groups;and there was no significant difference in HF(P>0.05);3)Left ventricular systolic function comparison between the two groups:the indicators of LVEF,SV and FS in group CHD were lower than those in non-CHD group,and there were all significant difference in FS,EF and SV(P<0.05).(2)The comparison in the CHD group:1)There was no significant difference in baseline data between the LVEF normal group and the LVEF decreased group(P>0.05),which was comparable.2)The comparison of SDNN,SDNNindex,SDANN,rMSSD,PNN50,LF,LF/HF and VLF between the two groups showed significant differences(P<0.05),and these indicators in the LVEF decreased group was lower than that in the LVEF normal group.(3)The relationship between HRV and LVEF in CHD group:Spearman correlation analysis showed that SDNN(r_s=0.446,P<0.001),SDNN index(r_s=0.221,P<0.001),SDANN(r_s=0.358,P<0.001),rMSSD(r_s=0.218,P<0.001),PNN50(r_s=0.360,P<0.001),LF/HF(r_s=0.174,P=0.004),VLF(r_s=0.187,P=0.012)were positively correlated with LVEF in the CHD patients,while LF was not significantly correlated with LVEF(r_s=0.114,P=0.054).Logistic regression showed that SDNN(OR=1.057,95%CI:1.027,1.089),SDNNindex(OR=0.822,95%CI:0.749,0.903),rMSSD(OR=0.605,95%CI:0.478,0.76),PNN5(OR=3.812,95%CI:2.442,5.948),LF/HF(OR=2.276,95%CI:1.128,4.59)were independently correlated with LVEF in CHD patients(P<0.05).Conclusion:This study shows that both heart rate variability and left ventricular systolic function are impaired in patients with coronary heart disease,and the degree of heart rate variability damage is positively correlated with the degree of LVEF damage;Heart rate variability measurement can provide some reference value for the evaluation of left ventricular systolic function in patients with coronary heart disease.