血流向量成像技术评价射血分数中间值及射血分数减低的心力衰竭患者左心室能量损耗和涡流特征

Study of the energy loss and vortex in the left ventricle in patients with mid-range and reduced left ventricular ejection fraction by vector flow mapping

目的应用血流向量成像(VFM)技术定量评估心力衰竭患者左室能量损耗(EL)及涡流特点,探讨EL与心脏功能及涡流的关系。方法选取2016年10月至2017年9月就诊于山东大学齐鲁医院左室射血分数(LVEF)<50%的心力衰竭患者105例,分为射血分数中间值的心力衰竭组(LVEF 40%-<50%,HFmrEF组,56例)及射血分数减低的心力衰竭组(LVEF<40%,HFrEF组,49例),并匹配同期32例健康人作为对照组。应用VFM技术测量左室内等容舒张期(IVR)、快速充盈期(RFP)、心房收缩期(ACP)、等容收缩期(IVC)及快速射血期(REP)的EL、涡流面积及循环强度。结果HFmrEF组、HFrEF组左室内各时期EL较对照组减低,且ACP内左室内EL在对照组、HFmrEF组、HFrEF组间呈逐渐减低的趋势(均P<0.05)。ACP内HFmrEF组、HFrEF组左室内漩涡面积、循环强度均较对照组增大,且在对照组、HFmrEF组、HFrEF组间呈逐渐增大趋势(均P<0.05)。RFP左室内EL与E/e′呈正相关(r=0.524,P<0.001)。ACP左室内EL与A峰呈正相关(r=0.492,P<0.001),与漩涡面积呈负相关(r=-0.235,P=0.040)。结论VFM技术可用于评估左室内EL改变,HFmrEF及HFrEF患者左室内EL较正常人显著减低,EL与心脏舒缩功能及漩涡面积具有相关性。

Objective To quantitatively evaluate the energy loss(EL)and vortex characteristics in the left ventricle by vector flow mapping(VFM)technique in heart failure patients with mid-range ejection fraction(HFmrEF)and reduced ejection fraction(HFrEF).Methods One hundred and five patients in Qilu Hospital of Shandong University from October 2016 to November 2017 with heart failure and left ventricular ejection fraction(LVEF)<50%were enrolled and divided into HFmrEF Group(LVEF40%-<50%,56 cases)and HFrEF group(LVEF<40%,49 cases).Another 32 healthy people at the same period were matched as control group.The EL,vortex area and circulation of isovolumic relaxation phase(IVR),rapid filling phase(RFP),atrial contraction phase(ACP),isovolumic contraction phase(IVC)and rapid ejection phase(REP)in the left ventricle was measured by VFM technique.Results The EL in HFmrEF group and HFrEF group was lower than that in the control group.In ACP,the EL was gradually decreased among the control group,HFmrEF group and HFrEF group(P<0.05).In ACP,the vortex area and circulation was larger in heart failure patients than those in the control group,and gradually increased from control group,to HFrEF group(P<0.05).Positive correlation between EL and E/e′was evidenced in the RFP(r=0.524,P<0.001).While in ACP,there was a positive correlation between EL and A peak(r=0.492,P<0.001),and a negative correlation between EL and vortex area(r=-0.235,P=0.040).Conclusions VFM can be applied to evaluate the EL in left ventricle.The EL in the left ventricle of patients with HFmrEF and HFrEF is significantly lower than that in control group.El is correlated with cardiac systolic and diastolic function and vortex area.