Initial exploration of evaluation of left ventricular blood flow structure and dynamics in normal subjects by vect flow maping

Objective:To investigate the blood flow structure and flow dynamics during the ventricular systole stage by Vector Flow Mapping(VFM).Method:There were 40 healthy volunteers(22 male,18 female)enrolled in this study.The apical three-chamber view and Color Dopper image in left ventricular(LV)were reserved and analyzed off-line.Time-Flow curves(TF)were obtained in cardiac cycle through the sample line in the basal,central and apical areas of LV.TF of early systole(ES-TF),mid-systole(MS-TF)and late systole(LS-TF)were recorded in the basal,central and apical areas of LV.Characteristics of blood flow structure of LV were observed during systolic,emergence time of vortexes,transverse diameters of eddies and maximum vector speed of the eddies.Result:The characteristic of flow structure had regular change in each of the cardiac phases,including early,mid-and late systole.During the early systolic phase,the circular arrangement of the vector(the eddy)was demonstrated at the anterior leaflet of mitral valve.The valves of ES-TF,MS-TF and LS-TF from basal areas to apical areas were gradually increased(P0.05).The eddy was about(25.74±7.32)mm in diameter,and about(38.31±14.25)cm/s and(11.42±6.28)cm/s in the speed toward and from the outflow.Conclusion:The flow structure and dynamics of LV can be evaluated noninvasively by VFM,especially to obtain the mapping of the flow vector and time flow curve during individual cardiac phases and also to visualize the cardiac function.