Quantitative Study Of Left Ventricular Pressure-strain Loop On Left Ventricular Myocardial Work In Patients With Coronary Atherosclerotic Disease

【Objective】The left ventricular pressure strain loop(LV-PSL)was used to estimate the changes of myocardial work in sufferers with coronary stenosis,and to inquire into the clinical value of myocardial work parameters in the diagnosis of coronary atherosclerotic disease(CAD).【Methods】120 patients with suspected CAD underwent coronary angiography.According to the degree of coronary artery stenosis,they were divided into coronary artery stenosis group(one or more subadventitia coronary artery diameter stenosis ≥70%),80 cases,control group(subadventitia Coronary artery diameter stenosis<70% or no stenosis)in 40 cases.The coronary stenosis group was divided into two sub groups according to the results of coronary angiography: single coronary stenosis group(43 cases),multi-branch coronary stenosis group(37 cases).Dynamic images of conventional cardiac sections(apical four chamber,two chamber,left ventricular long axis)were collected before angiography in all cases.The global longitudinal strain(GLS)was analyzed by two-dimensional speckle tracking echocardiography,and then the cuff blood pressure was used as the left ventricular pressure to construct a non-invasive Left ventricular pressure-strain loop,obtain the longitudinal strain peak time dispersion(PSD),calculate and compare the global myocardial work index(GWI),global effective work(GCW),global invalid work(GWW)and overall work efficiency of each group(GWE).By analyzing the receiver operating characteristic(ROC)curve data,the best cut-off value of each parameter to predict the occurrence of severe coronary stenosis was determined.【Results】1.Compared with the control group,GLS,GWI,GCW,and GWE in the coronary stenosis group were significantly reduced,while PSD and GWW were significantly increased(all P<0.05).2.Compared with the control group,GLS was significantly reduced in the multivessel coronary artery stenosis group(P<0.05)but not significantly reduced in the single-vessel coronary artery stenosis group(P>0.05).3.GWI=1889.0 mm Hg% can be used as the cut-off value for the diagnosis of coronary artery stenosis;area under ROC curve(AUC)= 0.765(sensitivity 90%,specificity 70%)was better than GCW(AUC = 0.725,P < 0.05),GWE(AUC = 0.758,P < 0.05)and gww(AUC = 0.638,P < 0.05).4.Myocardial work parameters GWI,GCW,GWE and GLS are negatively correlated(r=-0.745,r=-0.673,r=-0.541,P<0.05);myocardial work parameters GWW and GLS are positively correlated(r=0.287,P<0.05).Myocardial work parameters GWI,GCW,GWE and PSD are negatively correlated(r=-0.477,r=-0.394,r=-0.594,P<0.05);myocardial work parameters GWW and PSD are positively correlated(r=0.444,P<0.05).5.Intraclass correlation coefficient(ICC)analysis results show that the measurement of GWI,GCW,GWW and GWE within and between observers has good consistency.【Conclusion】In patients with coronary artery stenosis,the work of the left ventricular myocardium based on the non-invasive pressure-strain loop is impaired,GWI,GCW,and GWE decrease,and GWW and PSD increase.GWI can be used as a sensitive index to predict coronary stenosis in CAD patients,and its predictive value is better than GCW,GWE and GWW.It provides a new method for quantitative assessment of left ventricular systolic function in CAD patients.