| Objective: To investigate the value of quantitative analysis of the left ventricular longitudinal strain in patients with hypertrophic cardiomyopathy(HCM)and with normal left ventricular ejection fraction(LVEF)by using two-dimensional speckle tracking imaging.Methods: A group of fifty-one HCM patients were enrolled in this study and twentyeight of them were chosen as the HCM group.All the HCM patients were matched with either the diagnosis criteria of the 2014 ESC Guidelines on Diagnosis and Management of Hypertrophic Cardiomyopathy or with normal LVEF(LVEF>50%)that is untreated or only treated by using pharmaceuticals.Exclusion criteria includes patients with poorly controlled blood pressure and/or blood glucose;this also includes patients with moderate to severe valvular disease,severe arrhythmia,other cardiomyopathy,or other severe systemic disease.In addition,20 healthy volunteers were enrolled as the control group.GE Vivid E9 equipment and an offline Echo PAC workstation were used.Inter-ventricular septum end-diastolic thickness(IVSd),left ventricular posterior wall end-diastolic thickness(LVPWDd),left atrial end systolic diameter(LAESD),left ventricular end diastolic volume(LVEDV),left ventricular end systolic volume(LVESV),left ventricular ejection fraction(LVEF),early diastolic mitral flow velocity peak(E peak),late diastolic mitral flow velocity peak(A peak),and left ventricular lateral wall of mitral annular motion velocities(e’)were obtained by two-dimensional echocardiography and calculated with E/A and E/e’.Peak systolic longitudinal strain(LPS)was determined for total wall thickness,for three myocardial layers(endocardium,mid-myocardium and epicardium)and for segments by the offline Echo PAC software,calculating the transmural gradient(△LS=LPSEndo-LPSEpi)and the transmural gradient percentage(△LS%=△LS/LPSEndo).Results: 1.There were no significant differences in gender,age,HR,BSA and DBP between the two groups(P>0.05);the SBP in the HCM subjects was higher than that in the control group(P > 0.05).2.The comparison of conventional echocardiographic parameters: compared with the control group,IVSd,LVPWDd,LAESD,E/e’ increased significantly and e’ decreased significantly in the HCM subjects,the difference was statistically significant(P<0.05);while E,A,E/A,LVEDV,LVESV,LVEF had no statistical significance(P>0.05).3.The comparison of myocardial strain parameters: ⑴There was a gradient of LPS among the 3 layers in the Control Group,that is,the LPS decreased gradually from the endocardium to the epicardium,the difference were statistically significant(P<0.01).The feature of the 3 layers in the HCM group were similar to the Control group,but the difference between the mid-myocardium and the epicardium was not statistically significant(P>0.05).Compared with the control group,the 3 layers’ LPS and the GLPS of HCM group were significantly lower,and the difference was statistically significant(P<0.001).⑵ There was also a gradient of LPS between the 3 segments in the Control Group,that is,the LPS decreased gradually from the apical segment to the basal segmen,the difference were statistically significant(P<0.05).The feature of the 3 segments in the HCM group were similar to the Control group,too.But there were no statistical difference between the basal segment and the middle segment(P>0.05).In the Control group,LPS in basal segment,middle segment and apical segment were descending from epicardial to endocardial.But in the basal segment,there were no statistical difference between the endocardium and the midmyocardium,the mid-myocardium and the epicardium(P>0.05).In the HCM group,the LPS in the 3 segments were similar to the Control group.But there were no statistical difference among the endocardium and the mid-myocardium of the middle segment,and 3 myocardiums of the basal segment(P>0.05).Compared with the control group,LPS in basal segment,middle segment and apical segment of the 3 myocardial layers strain were significantly reduced in the HCM subjects,the difference was statistically significant(P<0.001).⑶Compared with the Control group,both of the segments and global transmural gradient were reduced in the HCM group,but the difference had no statistical significant(P>0.05).The transmural gradient percentage in both of the control group and the HCM subjects were reduced from the apical segment to the bascal segment,the difference were statistically significant(P<0.05).Compared with the control group,the △LS%m and the△LS%a of HCM group were significantly higher,and the difference was statistically significant(P<0.01).Conclusions: 1.In the normal group,there was a gradient in the 3 myocardium layers,the LPS decreases gradually from the endocardium to epicardium.And there was also a gradient in the 3 myocardium segments,the LPS decreases gradually from the apical segment to the basal segment.In HCM subjects with normal LVEF,LPS in the 3 layers,3 segments and the whole left ventricular wall was lower than in controls.2.Even the LVEF was normal,patients with HCM had already had a damaged systolic function in the part or in the whole of left ventricular.3.Using 2D-STI could accurately determine the partial or the whole left ventricular systolic function in patients with HCM.It provids a new noninvasive examination method for clinical to evaluate the effect of myocardium in HCM patients.But there is still lack of diagnostic criteria.4.The transmural gradient percentage can be more sensitive to reflect the change of the transmural gradient. |
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