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. Key words: Echocardiography; Ventricular function,left; Hemodynamic phemomena; Vector flow mapping