血流向量图分析正常左心室等容收缩期血流动力学特点

目的 应用血流向量图(vector flow mapping,VFM)技术分析正常左室等容收缩期是否为血流动力学停滞期.方法 健康志愿者50例,心尖左室长轴观记录动态彩色多普勒血流图像,VFM技术分析等容收缩期左室内血流动力学特点.结果 舒张末期左室腔内形成一个较大的整体涡流,并持续至整个等容收缩期,于射血早、中期消失.它使左室腔内原本朝向心尖的血流于心尖部转向,向基底部流出道流动.结论 等容收缩期并非左室的血流动力学停滞期,在这一时相,心脏依靠涡流完成了血液的传递和血流的转向,更实现了血流动量的传递.

Assessment of the hemodynamics of left ventricle during the isovolumic contraction phase in normal snbjects by vector flow mapping

Objective To clarify whether the phase of left ventricle(LV)isovolumic contraction is the phase of hemodynamics stasis in normal subjects by using vector flow mapping(VFM).Methods Color Doppler flow images were recorded from LV apical long-axis view in fifty healthy volunteers.The characteristics of LV intracavitary flow dynamics during isovolumic contraction were analyzed by VFM.Results A global vortex occurred in the LV chamber during the late diastole which was sustained during the whole phase of isovolumic contraction.The vortex disappeared quickly in the early and middle ejection phase.The flow in the LV was initially directed toward the apex and then briefly reversed toward the base.Conclusions Isovolumic contraction phase is not the period of hemodynamic stasis but,rather,phase with dynamic changes in intracavitary flow.The vortex during isovolumic contraction makes a dynamic contribution to flow redirection and provides efficiency for momentum transfer.