Assessment Of Relationship Between Left Ventricular Remodling And Left Ventricular Deformation, The Asynchronyz Ation In Patients With Dilated Cardiomyopathy By Velocity Vector Imaging

Objective:The morphological changes of ventricular remodeling of Dilated cardiomyopathy (DCM) is ventricular expansion, mainly left ventricular dilatation, associated with altered geometry with a more spherical left ventricle. Sphericity index (SI) is used to assess left ventricular remodeling in foreign and domestic researches. A large number of studies have shown that cardiac function is getting worse with the growing sphere of left ventricular in patients with DCM. Left ventricular strain and strain rate reflect myocardial deformation. Studies have shown that patients with DCM with reduced longitudinal strain and strain rate, cardiac function decreased, then what is the relationship between left ventricular deformation and remodeling? In addition, studies have shown that left ventricular myocardium in patients with DCM significantly in the longitudinal contraction is asynchronized, Whether asynchronyzation is related to the ventricular remodeling? Velocity vector imaging is applied to evaluate the relationship of left ventricular remodeling and left ventricular deformation,asynchronization.Method:1 Study PopulationThe study group consisted of 30 patients (22men,8women;mean age 47.6±10.1 years) with DCM and age-and gender-matched control subjects (20men,10 women; mean age 48.03±9.47 years). All participants underwent conventional echocardiography. Inclusion criteria were according to WHO/ ISFC diagnostic criteria, NYHA cardiac function classification gradeⅢor IV,a reduction in left ventricular ejection fraction (LVEF) below 45% and the absence of coronary artery disease as confirmed by invasive coronary angiography. Patients who had known familial cardiomyopathy, history of heart disease, abnormal liver function, renal function, and lipid level, were in contact of alcohol and toxic substance, and pregnant women were excluded from the study. The study protocol was approved by the ethics committee of the university of our institution, and written informed consent was obtained from all participants.2 InstrumentPatients with DCM and control subjects underwent transthoracic echocardiographic evaluation with digital acquisition on a Sequoia c512 ultrasound system with the 4Ⅴ1 c transducer with a frequency range of 2.75-4.25MHz andⅤⅤⅠquantitative analysis software.3 Image AcquisitionECG leads were connected to each participant in the left decubitus and utilizing a breath-hold technique, standard high frame rate apical four-chamber, two-chamber, and long-axis views of two or three consecutive heart cycles were stored digitally for subsequent off-line analysis.4 Conventional Two-Dimensional EchocardiographyDouble-plane Simpson's measurement of left ventricular ejection fraction (LV EF), left ventricular end-diastolic volume (LV EDV), left ventricular end-systolic volume (LV ESV).SI:According to Tischler's method of determination of left ventricular sphericity index (SI), in the apical four-chamber view of left ventricular end systolic and diastolic long shaft (L) and short shaft (D), according to the formula SI= L/D calculation of left ventricular end systolic sphericity index (SIs) and end-diastolic sphericity index (SId).5ⅤⅥand Off-LineThe user first selects clips where the full R-R intervals are present and the borders are well visualized and then manually traces the endocardial border. Velocity vectors are displayed in the two-dimensional plane automatically throughout the cardiac cycles From the same tracked contour of the endo-cardium, two dimensional strain and strain rate are obtained from the velocity of the displacement along the contour. The LV wall was divided into 18segments.Peak systolic longitudinal myocardial velocity(Vs), strain(S), and strain rate(SR) were recorded for each segment. The 18-segment left ventricular longitudinal systolic strain average is the global peak systolic longitudinal strain(GLs),18-segment peak longitudinal systolic strain rate is the global peak systolic longitudinal strain rate (GLsr).The time to peak systolic longitudinal velocity(Tvl) were also derived from the same endocardial contour, then Tvl-SD and Tvl-dif were calculated.Results:1 Compare of general parametersThere were no differences between the groups in sex and age (P>0.05).SId, SIs, EDV, ESV, LVEF between the two groups there was significant difference (P<0.01).,SId, SIs, LVEF of the DCM group significantly less than the control group, EDV, ESV of the DCM group significantly higher than the control group.2 Indicators of left ventricular deformationVs of DCM group was significantly lower than the corresponding segments of the control group (P<0.01). The absolute value S, SR, GLs, GLsr was significantly lower than the corresponding segments of the control group (P <0.01), the difference was statistically significant.3 Asynchronous IndexTvl, Tvl-SD, Tvl-dif was significantly higher of DCM group than the control group (P<0.01), the difference was statistically significant.4 SI and LVEF, GLs, GLsr correlation analysisCorrelation analysis showed that:SId, and SIs of DCM group were positively correlated with LVEF (respectively, r= 0.541, P<0.01; r= 0.502, P <0.01), a positive correlation with the absolute value of GLs (respectively, r= 0.567, P<0.01; r= 0.581, P<0.01), a positive correlation with the absolute value of GLsr (respectively, r= 0.645, P<0.01; r= 0.598, P<0.01).5 SI and Tvl-SD, Tvl-dif correlation analysisCorrelation analysis showed that:SId, and SIs of DCM group were negatively correlated with Tvl-SD (respectively r=-0.513, P<0.01; r= 0.446, P<0.05), and Tvl-dif (respectively r=-0.583, P<0.01; r=-0.570, P <0 .01).Conclusion:1 With left ventricular remodeling,the ventricular spherify is inevitable in patients with DCM.Along with the aggravation of spherical ventricular, the capacity of left ventricular myocardial deformation gradually reduces, cardiac function gradually reduces. The spherical index as a morphological parameter can reflect cardiac myocardial deformation.2 Left ventricular of patients with DCM is accompanied by increasing spherify,worsening synchronization and a gradual deterioration of cardiac function. Spherical index as a morphological parameters can reflect asynchronous movement of myocardial.