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Objective To assess the systolic function in left ventricular subendocardial myocardium , midmyocardium and subepicardial myocardium in patients with hypertrophic cardiomyopathy (HCM ) by two‐dimensional speckle tracking echocardiography .Methods A total of 32 patients with HCM and 32 healthy adults were included in the study .All standard measurements were obtained from the left ventricular short‐axis views at the levels of mitral annulus ,papillary muscle and apex ,and apical four‐chamber ,two‐chamber ,and long‐axis views .Two‐dimensional speckle tracking imaging was employed .The global peak systolic radial strain ,peak systolic longitudinal strain and circumferential strain of each layer of the left ventricle were measured .Results In patients with HCM and the control group ,the peak systolic longitudinal strain and circumferential strain reduced from subendocardial myocardium to subepicardial myocardium .The global peak systolic radial strain in patients with HCM was significant lower than that in the control group . And in patients with HCM ,peak systolic longitudinal strain in subendocardial myocardium ,midmyocardium and subepicardial myocardium was significant lower than those in the control group .Conclusions Peak systolic longitudinal strain and circumferential strain are reduced from subendocardial myocardium to subepicardial myocardium .Myocardial systolic function is impaired in patients with HCM .In patients with HCM ,longitudinal strain of each layer is lower ,but circumferential strain is mainly reduced in midmyocardium and subepicardial myocardium compared with that in the control group .
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Objective To investigate left ventricular (LV) strain in patients with hypertension (HT)and myocardial hypertrophy using three-dimensional speckle tracking echocardiography.Methods Myocardial movement was analyzed in 37 primary HT patients with myocardial hypertrophy and 27 healthy volunteers.LV longitudinal,circumferential,radial and area strains were measured.The correlation between each global strain parameter and LV ejection fraction (LVEF) was analyzed.Results LV global longitudinal strain(GSL),global radial strain (GSR) and global area strain (GSA) of HT patients with myocardial hypertrophy were significantly lower than the contrast group,whereas global circumferential strain(GSC) showed no significant difference between the two groups.Longitudinal,radial and area strains were decreased in LV basal and middle levels,while decreased circumferential strain was detected only in basal level.There were significant correlations between LVEF and GSL,GSC,GSR,GSA.Conclusions Impairment of LV regional myocardial contractility can be detected by three-dimensional speckle tracking echocardiography.
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Objective To investigate in vitro porcine myocardial shear modulus using real-time shear wave elastography.Methods Shear wave elastography was used on four in vitro porcine hearts.The probe was placed parallel to the long or short-axis of the heart on the anterior wall of the left ventricle,and myocardial shear modulus were measured in subepicardial,middle,subendocardial layers,respectively.Results Shear modulus of subepicardial,middle,subendocardial myocardium were (46.04 ± 17.07)kPa,(87.70 ± 29.67) kPa,( 115.73 ± 30.04) kPa,respectively,when the probe was placed parallel to the long-axis of the heart; whereas those were (78.71 ± 26.48) kPa,(77.08 ± 34.00)kPa,(70.69 ± 41.38) kPa,respectively,when the probe was placed parallel to the short-axis of the heart.Conclusions By using realtime shear wave elastography,the shear modulus values measured in subepicardial,middle,subendocardial myocardium of the left ventricle are different,even myocardium in the same location appears different shear modulus values when the probe orientation are different.
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ObjectiveTo investigate the ability of three-dimensional(3D) speckle tracking imaging (STI) for assessing left ventricular (LV) strain,and measure the value and angle of myocardial main strain vector.MethoodsLongitudinal,circumferential and radial strain of LV were measured in 31 healthy adults by 3D-STI and two-dimensional(2D) STI.The main strain vector and the angle between main strain vector and the LV short-axis plane were calculated from longitudinal and circumferential strains.Results The global longitudinal,circumferential strains and strains at basal,middle,apical level of LV by 3D-STI were significantly smaller than those by 2D-STI,whereas radial strain showed an opposite trend.The 3D strains presented significant difference between different levels of LV,longitudinal,circumferential and radial 3D strains were greater at middle level than at basal and apical level of LV,meantime 2D stain didn't show such obvious trend.Calculated from three-dimensional longitudinal and circumferential strain,the main strain vector was greatest at middle level of LV,whereas the angle between main strain vector and LV short axis plane didn't show any significant difference between three levels of LV.Conclusions3D-STI provides us a new and reproducible method for the evaluation of LV regional function by measuring LV strains.