Assessment for regional and global systolic function of left ventricle in patients with coronary arterial disease by longitudinal layer-specific strain

Abstract

Objective To analyze longitudinal layer-specific strain in endocardial, midcardial and epicardial layers of left ventricle (LV) by two-dimensional speckle tracking imaging(2D-STI) in patients with coronary heart disease (CHD) and to evaluate the regional or global systolic function of LV. Methods Seventy-eight patients with suspected CHD were divided into CHD group (46 subjects) and control group (32 subjects) according to the results of selective coronary arteriography. According to the stenosis degree or number of coronary arteries, the CHD group was divided into mild stenosis group (corresponding blood-supply vessel stenosis 50%-75%), severe stenosis group(corresponding blood-supply vessel stenosis ≥75%) or single-vessel stenosis group, multi-vessel stenosis group. Two-dimensional images with high frame rate were recorded in apical four-chamber, long-axis, two-chamber of LV in all subjects. The strain parameters by EchoPAC analysis software included territorial longitudinal strain(TLS) of endocardial, midcardial and epicardial layers (TLSendo, TLSmid, TLSepi) and global longitudinal strain (GLS) of endocardial, midcardial and epicardial layers ( GLSendo, GLSmid, GLSepi). Results Regardless of with or without corresponding blood-supply coronary artery stenosis and range of coronary artery stenosis, TLSendo, TLSmid, TLSepi and GLSendo, GLSmid, GLSepi all showed a gradient decrease(P 0.05). Compared with the mild stenosis group, TLSendo, TLSepi of severe stenosis group decreased significantly(P 0.05). Moreover, compared with the control group, GLSendo, GLSmid, GLSepi of single-vessel stenosis group and multi-vessel stenosis group decreased significantly(P<0.05). Compared with the single-vessel stenosis group, GLSendo, GLSmid, GLSepi of multi-vessel stenosis group decreased significantly(P<0.05). For predicting corresponding blood-supply vessel stenosis ≥75%, the sensitivity and specificity were 55.6%, 72.6% and 57.8%, 76.4%, when the cut-off of TLSendo and TLSepi were 20.5% and 15.5% respectively. For predicting multi-vessel stenosis, the sensitivity and specificity were 54.5%, 71.4%; 50.0%, 87.5% and 63.6%, 87.5%; when the cut-off of GLSendo, GLSmid, GLSepi were 21.5%, 17.5% and 16.5% respectively. Conclusions Systolic dysfunction of LV happened through all layers in CHD patients. The longitudinal strain of layer-specific by 2D-STI can accurately evaluate the regional and global systolic function of LV in patients with CHD, which can also be used to predict the degree or range of coronary artery stenosis. Key words: Echocardiography; Coronary artery disease; Ventricular function, left; Two-dimensional speckle tracking imaging