Evaluation of left ventricular systolic function in patients with chronic heart failure using vector flow mapping

Objective\r\nTo observe the hemodynamic change characteristics of left ventricle and evaluate left ventricular systolic function in patients with chronic heart failure (CHF) via vector flow mapping(VFM).\r\n\r\n\r\nMethods\r\nSixty-two patients with CHF(CHF group) were selected as case group and were divided into three groups (B, C, D) according to the American College of Cardiology Foundation and the American Heart Association (ACC/AHA ) recommended stages.Sixty healthy volunteers were selected as control group. The left ventricular circulation parameters (vortex quantity, vortex area, circulation) and energy loss (EL) of the apex, mid, and basal segments in different groups were compared in all the systolic phases. Left ventricular ejection fraction (LVEF) was calculated by biplane Simpson method, and the correlation was analyzed with the parameters of circulation and EL.\r\n\r\n\r\nResults\r\n①In the phase of isovolumetric contraction (IVC) and slow ejection (SE), compared with the control group, the levels of EL were increased in mid and basal segments (P\u003c0.01 or P\u003c0.05) in CHF group. The vortex area and circulation during IVC and rapid ejection (RE) were higher in CHF group than those in the control group (P\u003c0.01 or P\u003c0.05). As for SE, only vortex quantity was higher in CHF group than that in the control group (P\u003c0.05). ②In CHF group, EL were increased at stage B and stage C than those in the control group (P\u003c0.05), and EL were decreased at stage D than those in the control group ( P\u003c0.05). Meanwhile, there was decreased tendency of EL in CHF group with the increase of ACC/AHA stages. ③The circulation during IVC of phase D was higher in CHF group than that in the control group (P\u003c0.05), the vortex area during RE was greater in CHF group than that of the control group and stage B (P\u003c0.05). ④EL was positively correlated with LVEF at basal segment of IVC(r=0.615, P\u003c0.001). The vortex area during RE, circulation during IVC and RE were negtively correlated with LVEF (r=-0.598, -0.594, -0.623; all P\u003c0.001).\r\n\r\n\r\nConclusions\r\nVFM technology can quantify the left ventricular hemodynamic changes of patients with CHF in the systolic phase, and shows its relationship with left ventricular systolic function, to provide objective basis for grading of CHF and also provide objective quantitative indicators for clinical treatment and curative effect evaluation.\r\n\r\n\r\nKey words: \r\nEchocardiography; Heart failure; Ventricular function, left; Vector flow mapping