Evaluation Of Energy Loss In Left Ventricle By Vector Flow Mapping In Patients With Different Degrees Of Reduced Ejection Fraction

BackgroundHeart failure is a complex clinical syndrome which is due to any cardiac structural or functional abnormalities resulting in impaired ventricular filling or ejection.The main clinical manifestations are dyspnea,fatigue and fluid retention.In patients with heart failure,cardiac remodeling occurs and heart systolic and diastolic functions are impaired.The intracavitary flow of the laminar flow and vortex flow changes significantly and the energy loss(EL)changes.These changes further affect the cardiac function.Echocardiography is the most commonly used method to evaluate cardiac structure and function.The newly developed vector flow mapping(VFM)based on color Doppler flow imaging can quantitatively calculate the energy loss in patients with heart failure.We combine VFM and 2DTT to evaluate the changes of EL in left ventricle in patients with heart failure with reduced ejection fraction and mid-range ejection fraction.Objectives:1.To calculate the EL in left ventricle by VFM in patients with different degrees of reduced ejection fraction quantitatively;2.To study the relationship between EL and cardiac structure and cardiac function in patients with different degrees of reduced ejection fraction.Methods1.Study populationHeart failure group:including 56 patients with heart failure,which were divided into three groups on the basis of LVEF:A group:(EF<0.30)17 patients,B group:(0.30?EF<0.40)22 patients,C group:(0.40?EF<0.50)17 patients.Healthy control group:20 healthy volunteers matching in terms of age and gender were enrolled into our study.2.ExaminationEchocardiography was performed in all patients after admission using ALOKA F75 color Doppler diasonograph simultaneous recording ECG.We acquired images of parasternal long axis view of left ventricular,A4C,A2C and A3C and dynamic images by two-dimensional echocardiography and the corresponding Color Doppler flow images and tissue Doppler images.The VFM mode was used to collect at least three cycles of A3C dynamic images.3.EchocardiographyWe measured IVS,LV,LVPW,LAD,LaD,SaD,LVESV,LVEDV,LAV(by bi-plane Simpson method)in two-dimensional images.We calculated LVEF,SV,CO,LAVI,LVM,LVMI and SI.We measured E,A,E/A and DT in CDFI images.We measured mitral annular velocities e'(S),e'(1)in TDI images.We calculated the average value e' and E/e'.We calculated the average EL in the whole left ventricle of seven phases,including isovolumetric diastole phase(P1),rapid filling phase(P2),slow filling phase(P3),atrial systole phase(P4),isovolumetric contraction phase(P5),rapid ejection phase(P6),and slow ejection phase(P7).We calculated the GLS using A3C dynamic images with 2DTT.4.Statistical analysisSPSS21.0 statistical software was used to analyze the data.T-test was used for comparison of two independent groups when the data were in normal distribution.The One-way ANOVA was used for comparison of four groups.We used Pearson analysis to study the correlation of two variations.Log transformation was used when the data were in non-normal distribution.The level of statistical significance was set at P<0.05.Results:1.clinical dataNo statistically significant differences existed between control group and heart failure group in age,sex,height,weight,BSA,BMI,HR,SBP and DBP(P>0.05).2.Two-dimensional echocardiography parameters comparison2.1 No statistically significant differences existed between control group and heart failure group in I VS and LVPW(P>0.05).2.2 Compared with control group,LAD,LAV and LAVI of the heart failure group increased with statistical significance(P<0.05).2.3 Compared with control group,LV,LVEDV and LVESV of the heart failure group increased with statistical significance(P<0.05).2.4 Compared with control group,LVM and LVMI of the heart failure group increased with statistical significance(P<0.05).2.5 Compared with control group,LaD and SaD of the heart failure group increased,and SI of the heart failure group decreased with statistical significance(P<0.05).2.6 No statistically significant differences existed between control group and heart failure group in SV and CO(P>0.05).3.Color Doppler flow imaging parameters comparison No statistically significant differences existed between control group and heart failure group in E,A,E/A and DT(P>0.05).4.Tissue Doppler imaging parameters comparison Compared with control group,E/e' of the heart failure group increased,and e' of the heart failure group decreased with statistical significance(P<0.05).5.GLS comparison Compared with control group,GLS of the heart failure group decreased with statistical significance(P<0.05).6.EL comparisonCompared with control group,the EL in isovolumetric diastole phase,rapid filling phase,atrial systole phase and rapid ejection phase decreased in the heart failure groupwith statistical significance(P<0.05).Compared with control group,the EL in atrial systole phase decreased in A and B group;compared with C group,the EL in atrial systole phase decreased in Agroupwith statistical significance(P<0.05).Compared with A group,the EL in isovolumetric contraction phase increased in C and D groupwith statistical significance(P<0.05);compared with control group,the EL in rapid ejection phase decreased in A and B group with statistical significance(P<0.05).7.Correlation analysesDuring rapid ejection phase,the EL of the left ventricle for all patients with heart failure is independently associated with the GLS(B=0.317,p=0.015).Conclusion1.The EL in diastole phase and rapid ejection phase decreases in heart failure group compared with control group.In heart failure group,EL in the atrial systolic phase,isovolumic systolic phase and rapid ejection phase decreases with the LVEF decreases;2.EL is correlated with left ventricular systolic and diastolic function;3.Combination of VFM,2DTT,two-dimensional echocardiography,CDFI and TDI can comprehensive evaluate the changes of cardiac structure,function and hemodynamics.