The left ventricular cavity blood flow energy loss in patients with dilated cardiomyopathy as detected by vector flow mapping / 实用医学杂志

ABSTRACT

Objective To study the characteristics of blood flow in isovolumic systole(IVC)of left ventric-ular(LV)in patients with dilated cardiomyopathy by flow-vector imaging(VFM). Methods Color flow Doppler imaging was performed from the apical long-axis view in 58 patients with dilated cardiomyopathy who was admitted in our hospital from October 2015 to November 2016 and 56 healthy volunteers as control. Doppler flow data ob-tained during IVC were analyzed offline with vector flow mapping.Results At the beginning of IVC,the swirl area (15 ± 3)cm2and flow(36 ± 8)cm2/s in the control group were significantly less than those in the observation group (27 ± 8)cm2,(45 ± 12)cm2/s,all P=0.000.At the end of IVC,the vortex flow was similar in both groups[(28 ± 4)cm2/s vs.(29 ± 11)cm2/s,P=0.617)],and the vortex area in the control group was significantly smaller than that in the observation group[(16 ± 3)cm2vs.(24 ± 9)cm2,P=0.000)].During the IVC,the area of the vortex in the control group increased slightly but not significantly(P = 0.073),but the flow rate decreased significantly (10 ± 27%). The area and volume of the vortex in the observation group decreased significantly with the flow de-creased by 29 ± 54%(P=0.000 vs.the control group).When the aortic valve was open,the average blood flow veloc-ity in the middle and basal parts of the LV compartment in the observation group was significantly lower than that in the control group(P<0.05).In multivariate models,a decreased LV ejection fraction was the only independent pre-dictor of the percentage decrease in area of the vortex during the IVC(P < 0.001),and a larger QRS width(P =0.026)and LV end-systolic long diameter(P = 0.004)were independent predictors of the percentage decrease in flow volume of the vortex. Conclusion The VFM technique enables a better assessment of the pathophysiological state of LV lumen energy loss during IVC in patients with dilated cardiomyopathy by vortex imaging.