Assessment Of Left Ventricular Layer-specific Strain And Its Relationship To Global Systolic Function In Hypertensive

Backgrounds and ObjectivesOur previous study on left ventricular systolic deformation at different stages of hypertensive cardiac dysfunction by two-dimensional strain study shows that in patients with preserved LVEF,only longitudinal strain(SL)decline,and depressed LVEF occurred when all circumferential strain(SC)and radial strain(SR)were impaired.In this study,layer-specific 2D strain was used to further observe the characteristic of left ventricular strain under different systolic function,investigating whether layer-specific strain was superior to whole-layer strain in the comprehension of hypertensive systolic dysfunction.Methods109 cases of primary hypertensive patients and 25 healthy volunteers from outpatient and hospitalized were included in this study.According to LVEF,the hypertensive was divided into HTnEF(LVEF?50%)and HTrEF(LVEF <50%).Echocardiography were performed and the pictures were exported to EchoPAC system for two-dimensional speckle tracking imaging strain analysis.The parameters we acquired including age,sex,blood pressure,heart rate,LVEF and two-dimensional strain measurements of subendocardial,middle and epicardial layers of left ventricle,including SL,global radial strain(GSL),SC,global circumferential strain(GSC)and SR.Results1.The layer-specific strain of the hypertensive group and the control group were in accordance with the following rules: the levels of SL and GSC in the basal and middle segments were lower than those in the apical segment whille SR were higher than those in the apical segment,GSL and GSC of all segment were increased from epicardium,middle to endocardial myocardium;2.In the hypertensive group,the strain parameters decreased compared with those in the control group.In the HTnEF stage,SL was significantly decreased in all segment and all layer except endocardial of apical segment,but SC only decreased in the epicardium and the middle myocardium.While SR of each segment did not change significantly.In the HTrEF stage,SL,SC and SR of all segments began to appear or further decreased.3.There were strong correlation between all strain values and LVEF,in which the SC is stronger than the SL and SR,and the basal-middle endocardial is more correlated than epicardium(Respectively,r=0.81-0.86,r=0.59-0.60,all p <0.01).Conclusions1.In the LVEF preserved phase,the longitudinal strain of the three levels of the middle and the basal segments decreased first,while the circumferential strain was preserved,and the strain in all levels of the left ventricle was decreased in the LVEF descent stage.2.There were strong correlation between all strain values and LVEF,and the basal and middle endocardial and middle SC responses were highly,especially endometrium.Suggesting that layer-specific strain is more favorable to analyze the pathophysiological characteristics of cardiac function in hypertension.