Abstract: AIM To compare the left ventricular (LV) intracavitary vortex during the isovolumic contraction (IVC) period between normals and patients with heart failure by using vector flow mapping (VFM). METHODS Color Doppler flow images were recorded from LV apical long-axis view in 51 healthy volunteers and 57 patients with dilated cardiomyopathy and LV ejection fraction ≤45%. RESULTS In normal subjects, the area of the LV intracavitary vortex formed at the end of diastole was sustained and the flow volume significantly decreased during the IVC period (P<0.01). The vortex reached the basal region of LV chamber in all normal subjects. However, both the area and flow volume of the vortex decreased significantly during the IVC period in the patients (both P<0.05). The vortex reached the basal region of LV chamber only in 25(44%) patients. When corrected for the influence of LV size, both the area and the flow volume of the vortex were significantly smaller in the patients than those in the normal subjects at the end of the IVC period (both P<0.01). CONCLUSION Both the area and flow volume of intracavitary vortex significantly decrease during the IVC period in patients with heart failure and are smaller than those in normals.