This study utilized vector flow mapping (VFM) technology to evaluate the characteristics of wall shear stress (WSS) in each segment of the left ventricle in patients with dilated cardiomyopathy (DCM). A total of 39 DCM patients [DCM group, 17 males and 22 females, aged (56.4±12.3) years] treated at the Second Affiliated Hospital of Air Force Medical University from May 2020 to September 2022 were prospectively enrolled. Additionally, 46 age-and gender-matched healthy volunteers [control group, 20 males and 26 females, aged (55.2±11.8) years] were selected during the same period. VFM was applied to annlyze WSS in the apical four-chamber, three-chamber, and two-chamber views of the left ventricle, and differences in WSS between the two groups were compared. The results showed that WSS at each phase of cardiac cycle gradunlly decreased gradually from basal to apical segments of the left uenrtricle in the control group but not in the DCM group. The DCM group exhibited significantly lower WSS than the control group in the mid-inferolateral wall during rapid filling; the basal posterior septum, basal inferolateral wall, mid-inferolateral wall, basal anterior septum, basal inferior wall, mid-anterior wall, and basal anterior wall during isovolumic contraction; and the basal, mid, and apical inferolateral segments during rapid ejection (all P<0.05). In addition, the global WSS was significantly lower in the DCM group than in the control group only in the mid-systolic phase [0.23(0.16, 0.31) N/m2 vs 0.34(0.24, 0.38) N/m2, P<0.05]. This study suggests that abnormal WSS distribution in DCM patients may reflect differences in ventricular mechanics, and changes in this parameter could serve as a novel indicator of ventricular dysfunction.
应用血流向量成像（VFM）技术评价扩张型心肌病（DCM）患者左心室各节段的室壁剪应力（WSS）特征。前瞻性纳入2020年5月至2022年9月在空军军医大学第二附属医院就诊的39例DCM患者（DCM组），男17例，女22例，年龄（56.4±12.3）岁。选取同期年龄、性别相匹配的46名健康志愿者（对照组），男20名，女26名，年龄（55.2±11.8）岁。应用VFM对左心室心尖四腔、三腔及二腔心切面进行WSS分析，并比较组间差异。结果显示对照组左心室各心动周期时相的WSS从基底段到心尖段均呈逐渐减低的趋势，而DCM组无此变化规律。DCM组在快速充盈期左心室下侧壁中间段，等容收缩期左心室后间隔基底段、下侧壁基底段、下侧壁中间段、前间隔基底段、下壁基底段、前壁中间段、前壁基底段及快速射血期下侧壁基底段、下侧壁中间段、下侧壁心尖段的WSS均低于对照组，差异均有统计学意义（均P<0.05）。此外，DCM组左心室整体WSS仅在收缩中期低于对照组［0.23（0.16，0.31）N/m2比0.34（0.24，0.38）N/m2，P<0.05］。研究提示DCM患者WSS的分布异常可反映心室力学的差异，该参数的变化可能是心室功能障碍的新指标。.