二维斑点追踪成像技术评价冠状动脉慢血流患者左室心肌分层应变.

Objective To discuss the clinical value and accuracy of two-dimensional speckle tracking echocardiography (2D-STE) for the evaluation of left ventricular systolic function of the coronary slow flow (CSF) by assessing left ventricular layer-specific myocardial strains in patients with CSF. Methods CSF group contained 41 patients with CSF, and 59 patients with normal coronary angiography results were involved as the control group. All 2-dimensional (2D) echocardiographic images from 6 standard views (apical views of long-axis, 4-chamber, and 2-chamber; parasternal short-axis views of mitral valve, papillary muscle, and apical level) were acquired for offline analysis. Layer-specific strain from endocardium, mid-myocardium and epicardium of LV wall was analyzed by 2D-STE software. Layer-specific global longitudinal strains (GLS) and global circumferential strains (GCS) were assessed at endocardium, midmyocardium and epicardium by 2D-STE. The transmural gradient between endocardial and epicardial (△GLS, △GCS) were calculated. Results GLS and GCS of each myocardium showed gradient descent, which is subendocardium>midmyocardium>subepicardium in both CSF group and control group. As comparing to the control group, GLS and △GLS in CSF group were significantly lower (P<0.05); especially the endocardial GLS and △GLS (P<0. 001 ). There were no significant difference in both GCS and △GCS between CSF group and control group. The AUC of △GLS was biggest (AUC=0.766, P<0. 001), and when the cut off value was -4. 87%, the sensitivity and the specificity was 66.7% and 76.3%, respectively. Conclusions 2D-STE can identify left ventricular 3-layer contractility (especially the subendocardium) by assessing left ventricular layer-specific myocardial strains in patients with CSF. Meantime, lognitudinal transmural gradient △GLS can identify the abnormity of left ventricular contractility in patients with CSF and have the promising prospect of clinical diagnosis. [ABSTRACT FROM AUTHOR]