Résumé
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.