Evaluation Of Left Ventricular Myocardium Property In The Patients With Different Graded Coronary Artery Stenosis By Three-dimensional Speckle Tracking Echocardiography

Background:The aim of this study was to evaluate left ventricular myocardial property by three-dimensional speckle tracking imaging (3D-STI), and to investigate the relationship between myocardial characteristics and degree of coronary artery stenosis in patients with coronary atherosclerotic heart disease (CAD).Method:Ninety-seven patients without left ventricular regional wall motion abnormality (RWMA) observed visually from 2D echocardiography were divided into four groups according to coronary artery angiography (CAG):23 patients in slight stenosis group (stenosis rate≤ 25%),26 patients in mild stenosis group (25< stenosis rate≤ 50%),28 patients in moderate stenosis group (50< stenosis rate≤75%), and 20 patients in severe stenosis group (stenosis rate>75%). Global longitudinal strain (GLS), circumferential strain(GCS), radial strain (GRS), area strain (GAS) and three dimensional strain (3DS) of left ventricular myocardial in the patients were obtained using 3D-STI, and left ventricular ejection fraction (LVEF) and stroke volume (SV) were obtained using two dimensional biplane Simpson method. The difference between any two sets of the parameters was analyzed, and the diagnostic value of global strains for different graded coronary artery stenosis was analyzed by the receiver operating characteristic (ROC) curve.Results:1.There were no significant difference of LVEF and SV in any two group (P＜0.05). 2.There were significant difference in GLS, GCS, GRS, GAS and 3DS between the severe stenosis group and any other group while all 3D-STI parameters except GCS in the moderate stenosis group were remarkably different from those respectively in mild group. There wasn’t any significant difference in 3D-STI parameters between the mild and slight group.3.ROC curve analysis showed that the area under the curve (AUC) of GLS, GRS, GCS, GAS,3DS were 0.899,0.873,0.723,0.856 and 0.863 respectively, and GLS less than -16.94% had a sensitivity of 68.8% and a specificity of 93.9% for the identification of stenosis rate>50%. In addition, AUC of GLS, GRS, GCS, GAS and 3DS for the identification of severe stenosis were 0.896,0.866,0.797,0.909 and 0.899 respectively, and GAS less than-29.13% allowed a sensitivity of 95% and a specificity of 71.4%,3DS less than 41.35% allowed a sensitivity of 90% and a specificity of 80.5%.Conclusion:3D-STI could detect the changes of left ventricular myocardial property in CAD patients without regional wall motion abnormality on 2D echocardiography, what’s more, GLS could be helpful to identify stenosis rate> 50%, and, GAS and 3DS could be useful to identify severe coronary artery stenosis.