Evaluation Of Left Ventricular Systolic Function In Hypertensive Patients With Sigmoid-shaped Interventricular Septum By Two-dimensional Speckle Tracking Technique

Objective:Two-dimensional speckle tracking technique was used to measure the longitudinal strain of left ventricular myocardium in hypertensive patients with sigmoid-shaped interventricular septum to evaluate their left ventricular global and regional systolic function.In order to explore whether the sigmoid-shaped interventricular septum affects the left ventricular systolic function in patients with hypertension and its clinical significance.Methods:This study was divided into three groups:essential hypertension group with sigmoid-shaped interventricular septum(n=34),essential hypertension group without sigmoid-shaped interventricular septum(n=34)and normal control group(n=30).There was no significant difference in sex and age among the three groups.Using Philips iE Elite color echocardiography diagnostic instrument,S5-1 phased array probe,frequency 1?5 MHz,frame rate>60 frames/s,and equipped with Q-LAB offline analysis software.The three groups of subjects routinely took the left recumbent position.The thickness of basal segment of interventricular septum(IVSBT),the thickness of middle segment of interventricular septum(IVSMT),the thickness of left ventricular posterior wall(LVPWT),the peak early diastolic velocity of mitral orifice(E),the peak velocity of late diastolic flow of mitral orifice(A),the ratio of E/A,the diameter of left ventricular outflow tract(LVOTD),the flow velocity of left ventricular outflow tract(LVOTV)and Tei index were measured.The left ventricular ejection fraction(LVEF)was measured by biplane Simpson.Two-dimensional dynamic images of standard apical four-chamber view,left ventricular apical three-chamber section and left ventricular apical two-chamber section were collected and stored for off-line analysis by two-dimensional speckle tracking technique in Q-LAB workstation.The two-dimensional dynamic images of left ventricular apical three-chamber section,apical four-chamber section and left ventricular apical two-chamber section were analyzed in turn.The peak systolic longitudinal strain(LS)of left ventricular myocardial segments and whole myocardium corresponding to each section were obtained.The above parameters were compared among the three groups and between the two groups.Results:There were significant differences in IVSBT,IVSMT and LVPWT among SIS group,non-SIS group and normal control group(P<0.05),and there were significant differences between the two groups(P<0.05).There was significant difference in LVEF and Tei index among the three groups(P<0.05).There was significant difference between non-SIS group and normal control group(P<0.05),and there was significant difference between SIS group and normal control group(P<0.05),but there was no significant difference between SIS group and non-SIS group(P>0.05).There were significant differences in global peak systolic longitudinal strain(4C-GLS),left ventricular apical three-chamber view global peak systolic longitudinal strain(3C-GLS),left ventricular apical two-chamber view global peak systolic longitudinal strain(2C-GLS)and left ventricular average global systolic peak longitudinal strain(GLS-Avg)among SIS group,non-SIS group and normal control group(P<0.05).Compared with the normal control group,the absolute values of 4C-GLS,3C-GLS,2C-GLS and GLS-Avg in the SIS group and the non-SIS group were significantly lower,and there was significant difference(P<0.05),but there was no significant difference between the SIS group and the non-SIS group(P>0.05).There were significant differences in the peak systolic longitudinal strain of the anterior and posterior walls of the left ventricular basal segment among the SIS group,the non-SIS group and the normal control group(P<0.05).Compared with the normal control group,the peak systolic longitudinal strain of the anterior and posterior walls of the left ventricular basal segment in the SIS group and the non-SIS group decreased,and the peak systolic longitudinal strain of the anterior and posterior wall of the left ventricular basal segment in the SIS group was further lower than that in the non-SIS group.There was significant difference between the two groups(P<0.05).Conclusion:1.Sigmoid-shaped interventricular septum affect the regional systolic function of left ventricular myocardium in patients with hypertension,mainly resulting in the decrease of systolic function of the basal segment of interventricular septum.2.Sigmoid-shaped interventricular septum may aggravate the damage of left ventricular regional systolic function in patients with hypertension.3.When LVEF is still in normal range,the left ventricular longitudinal strain measured by two-dimensional speckle tracking technique can earlier evaluate the involvement of global and regional left ventricular systolic function in hypertensive patients with or without sigmoid-shaped interventricular septum.