Correlation Between ECG "6+2" Phenomenon And Microcirculation Resistance In Patients With Non-obstructive Coronary Artery Disease

Objective:To investigate the level of coronary microcirculation resistance in patients with non obstructive coronary artery disease(nocad)and its correlation with ECG "6 + 2"phenomenon.Methods:From September 2020 to June 2021,92 patients who underwent 24-hour ambulatory ECG examination in Shanxi Provincial People’s hospital due to chest pain and showed abnormal ST-T and negative results of coronary angiography were selected.According to the changes of ST-T in each lead of 24-hour ambulatory ECG,they were divided into ECG "6 + 2" phenomenon group(52 cases)(6 + 2 "group)and non ECG" 6 + 2"phenomenon group(40 cases)(control group).Clinical data were collected.Fasting venous blood was collected in the morning of the next day of hospitalization and sent to the laboratory for determination of high-sensitivity C-reactive protein(hs CRP),triglyceride(TG),total cholesterol(TC),high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C)Glycosylated hemoglobin type A1c(Hb A1c),erythrocyte sedimentation rate(ESR),serum creatinine(SCR),blood urea nitrogen(BUN),alanine transaminase(ALT),aspartate transaminase(AST).The microcirculation resistance of left anterior descending branch(LAD),left circumflex branch(LCX)and right coronary artery(RCA)were measured by quantitative blood flow analyzer,and the average microcirculation resistance of the three vessels was calculated.The basic data and the level of microcirculation resistance between the "6 +2" group and the control group were compared.One way ANOVA was used to compare the microcirculation resistance and average microcirculation resistance of the three vessels in the "6 + 2" group.Pearson correlation analysis was used to explore the correlation between mean microcirculation resistance and lipid index,inflammatory index,liver and kidney function and glycosylated hemoglobin in "6 + 2" group.Pearson correlation analysis was used to analyze the point two column correlation between coronary mean microcirculation resistance and ECG "6+2" phenomenon.Results:1.Compared with the control group,the proportion of women in the "6+2" group,the prevalence of diabetes,the prevalence of hypertension,BMI,TC,LDL-C,hs-CRP and Hb A1 c levels increased significantly,and the difference was statistically significant(P < 0.05).There was no significant difference in age,TG,HDL-C,Scr,bun,ALT and AST between the two groups(P > 0.05).2.Compared with the control group,the lad microcirculation resistance,LCX microcirculation resistance,RCA microcirculation resistance and average microcirculation resistance in the "6 + 2" group were significantly higher(P < 0.05).3.There was no significant difference in the level of coronary microcirculation resistance between the subgroups of "6 + 2" group(P > 0.05).4.The mean level of coronary microcirculation resistance in "6 + 2" group was positively correlated with TC,LDL-C,hs CRP and Hb A1c(P < 0.05),but not with TG,HDL-C,Scr,bun,ALT and AST(P > 0.05).5.The mean level of coronary microcirculation resistance in the two groups was positively correlated with the "6 + 2" phenomenon of ECG(P < 0.05)Conclusion:The increase of coronary microcirculation resistance is positively correlated with ECG "6 + 2" phenomenon in patients with nocad.The increase of microcirculation resistance is affected by abnormal lipid metabolism,inflammatory response,abnormal glucose metabolism and other factors.As a simple clinical noninvasive examination,ECG has certain evaluation and diagnostic value for coronary microcirculation dysfunction.