A Study On The Systolic Dyssynchrony And Systolic Function In Hypertrophic Cardiomyopathy By Real-time Three-dimensional Echocardiography Volume-time Curves

Objective1、Real-time three-dimensional echocardiography(RT-3DE)volume-time curve and two-dimensional speckle tracking imaging(2D-STI)were used to assess the left ventricular systolic dyssynchrony and systolic function of obstructive hypertrophic cardiomyopathy and non-obstructive hypertrophic cardiomyopathy,respectively.2、The correlation between RT-3DE volume-time curve systolic dyssynchrony index(SDI)and 2D-STI peak strain dispersion(PSD),as well as the correlation between SDI and thickness of thickest chamber wall,the correlation between SDI and 3D left ventricular ejection fraction(3D-LVEF)were assessed.Methods1、Object: A total of 97 subjects with regular heart rhythm were selected,including 69 patients with hypertrophic cardiomyopathy(HCM)and 28 healthy volunteers in the same period.Patients with HCM were divided into obstructive HCM group and non-obstructive HCM group according to the left ventricular outflow tract pressure difference measured by echocardiographic spectrum doppler in resting state.2、Measurements:The two-dimensional images of patients in control group and HCM group were collected,and the left ventricular end-diastolic volume index(LVEDVI),left ventricular end-systolic volume index(LVESVI)and left ventricular ejection fraction(LVEF)were used as indexes to assess systolic function.Using 2D-STI,the peak strain dispersion PSD measured by 2D-STI was used as an index to assess systolic dyssynchrony.Three-dimensional images of patients in control group and HCM group were collected,and three-dimensional left ventricular end-diastolic volume index(3D-LVEDVI),three-dimensional left ventricular end-systolic volume index(3D-LVESVI)and three-dimensional left ventricular ejection fraction(3D-LVEF)were used as indexes to assess systolic function.Using RT-3DE,the systolic dyssynchrony index SDI measured by three-dimensional volume-time curve was used as an index to evaluate systolic dyssynchrony.Then,the correlation analysis of SDI and PSD,SDI and thickness of the thickest ventricular wall,SDI and 3D-LVEF was carried out,and the repeatability of PSD,SDI,LVEF and 3D-LVEF was analyzed.Results1、There were no statistically significant differences in LVEDVI,LVESVI and LVEF between the HCM group and the control group(P>0.05).There was no significant difference in LVEDVI,LVESVI and LVEF among the obstructive HCM group,the non-obstructive HCM group and the control group(P>0.05).2、The PSD of the HCM group was significantly bigger than that of the control group(P<0.01).The PSD of the obstructive HCM group was significantly bigger than that of the control group(P<0.01).The PSD of the non-obstructive HCM group was significantly bigger than that of the control group(P<0.01).There was no significant difference in PSD among the obstructive HCM group and the non-obstructive HCM group(P>0.05).3、There were no statistically significant differences in 3D-LVEDVI,3D-LVESVI and 3D-LVEF between the HCM group and the control group(P>0.05).There were no statistically significant differences in 3D-LVEDVI,3D-LVESVI and 3D-LVEF among the obstructive HCM group,the non-obstructive HCM group and the control group(P>0.05).4、SDI in the HCM group was significantly bigger than that in the control group(P<0.01).SDI in the obstructive HCM group was significantly bigger than that in the control group(P<0.01).SDI in the non-obstructive HCM group was significantly bigger than that in the control group(P<0.01).There was no significant difference in SDI between the obstructive HCM group and the non-obstructive HCM group(P>0.05).5、The SDI of RT-3DE volume-time curve was closely correlated with PSD of 2D-STI(r=0.665,P<0.01).The SDI of RT-3DE volume-time curve was correlated with the thickness of the thickest chamber wall(r=0.18,P<0.01).For HCM patients with normal LVEF,there was no significant correlation between SDI of HCM and 3D-LVEF(r=0.01,P>0.05).SDI of RT-3DE volume-time curve had better repeatability than PSD of 2D-STI,and 3D-LVEF had better repeatability than that of LVEF.ConclusionRT-3DE volume-time curve can accurately evaluate the systolic dyssynchrony of obstructive HCM and non-obstructive HCM in the same cardiac cycle.The systolic dyssynchrony of HCM is related to the thickness of the wall.