Visualization and quantification of myocardial mechanical changes of left ventricle in systemic lupus erythematosus patients using ultrasonic layer-specific strain imaging

Abstract

Objective To evaluate the damage of longitudinal mechanical parameters of left ventricular myocardium by ultrasonic layer-specific strain imaging in patients with systemic lupus erythematosus (SLE) without conventional evidence of cardiovascular system involvement. Methods Seventy-eight patients suffered from SLE without conventional evidence of cardiovascular system involvement (SLE group) and 48 healthy volunteers with age and sex matched (control group) were selected for this study. The left ventricular conventional structure and functional parameters were measured by conventional echocardiography. Then layer-specific strain imaging was performed in both groups to obtain left ventricular endocardial myocardial global longitudinal strain (GLSendo), mid-myocardial GLS (GLSmid), epicardial GLS (GLSepi) and basal segment, middle segment and apex longitudinal strain (LS) of all three layers of the myocardium. Then the transmural difference of the GLS (ΔLS=GLSendo-GLSepi) were calculated. The related parameters between these two groups were compared for difference and correlation analysis of related mechanical parameters were also made. Results ①There was no significant difference in the left ventricular ejection fraction (LVEF) and left ventricular stroke volume (LVSV ) between the two groups (all P>0.05); Compared with the control group, the mean E/e in the SLE group was increased and the E/A, E, e were decreased (all P 0.05). ②The myocardial global longitudinal strain(GLS) of the two groups were decreased from endocardial to epicardial gradient; the values of GLS and segmental LS of all three layers in the SLE group were decreased (all P<0.05); the ΔLS of the SLE group was decreased compared with the control group (P<0.05); the value of peak strain dispersion (PSD) were increased in SLE patients (P<0.05). ③The correlation analysis showed the GLS of each layer of myocardium in SLE patients were negatively correlated with disease duration (rs=-0.34~-0.36, all P<0.05) and SLE disease activity index(SLEDAI) (rs=-0.25~-0.30, all P<0.05). Conclusions The ultrasonic layer-specific strain imaging can quantitatively detect the damage of mechanical parameters of left ventricle in SLE patients, which is more sensitive than the conventional echocardiography in evaluating left ventricular systolic function. It may provide visual evidence for early diagnosis of cardica dysfunction in SLE patients. Key words: Ultrasonography; Systemic lupus erythematosus; Myocardium; Layer-specific strain