目的研究超声血流向量成像技术(VFM)评价扩张型心肌病(DCM)患者左室等容收缩期(IVC)腔内血流能量损耗(EL)特征及临床价值。方法选取本院收治的DCM患者62例(DCM组),根据左室射血分数(LVEF)分为A组(40%≤LVEF<50%,n=21)、B组(30%≤LVEF<40%,n=24)、C组(LVEF<30%,n=17);另选健康志愿者62例作为健康对照组(HC组)。测定并比较两组VFM心尖长轴切面各期循环及旋涡EL参数。结果 (1)IVC初期DCM组的涡旋面积和循环强度显著高于HC组(P<0.05);IVC晚期,DCM组的涡旋面积及降低率显著高于HC组(P<0.05),DCM组的循环强度降低率显著高于HC组(P<0.05);(2)在IVC期,DCM组在左室顶部、中部、底部的血流速度、EL及其平均值均显著低于HC组(P<0.05);(3)A、B、C组的IVC期涡旋面积下降率、循环强度下降率依次呈升高趋势,血流速度及EL呈降低趋势,差异有统计学意义(P<0.05)。结论 VFM能够较为准确地评价DCM患者IVC期左室血流场及EL异常改变,可作为定量评价DCM早期心功能改变的新指标。
Objective To evaluate the characteristics and clinical value of left ventricular energy loss(EL) during isovolumic systole(IVC) in patients with dilated cardiomyopathy(DCM) detected by vector flow mapping(VFM). Methods 62 DCM patients(DCM group) admitted to our hospital from January to December 2017 were divided into 3 groups according to the left ventricular ejection fraction(LVEF):group A(40%≤LVEF<50%, n=21), group B(30%≤LVEF<40%, n=24), group C(LVEF<30%, n=17), and 62 healthy volunteers were selected as healthy controls(HC group). The quantitative parameters of apical long-axis section and EL were measured in the different periods of VFM imaging. Results(1) The vortex area and circulation of the DCM group were significantly higher than those of the HC group at the early stage of IVC(P<0.05);In the advanced stage of IVC, the vortex area and its reduction rate of the DCM group were significantly higher than those of the HC group(P<0.05);The rate of decrease in circulation of the DCM group was significantly higher than that in HC group(P<0.05).(2) During the IVC phase, the blood flow velocity, EL and its mean values of the left ventricular at the top, middle and bottom of the DCM group were significantly lower than those of the HC group(P<0.05).(3) The decrease rate of vortex area and the decrease rate of circulating intensity in group A, B, C showed an increasing trend, and the blood flow velocity and EL showed a decreasing trend, the differences were statistically significant(P<0.05). Conclusions VFM can accurately evaluate the abnormality of left ventricular blood flow field and EL during IVC in DCC patients, which can serve as new indexes in evaluating early cardiac function changes in DCM.
Chinese Journal of Ultrasound in Medicine