[Characteristics of left ventricular wall shear stress at each segment in patients with dilated cardiomyopathy based on vector flow imaging].

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 <i>P</i><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, <i>P</i><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.