Quantitative Evaluation Of Vortex Flow In Patients With Left Ventricular Diastolic Dysfunction By Vector Flow Mapping

Objective:Blood flow patterns are closely linked to the morphology and function of the cardiovascular system. Therefore, analyzing the blood flow dynamics opens up new perspectives for our understanding of cardiovascular physiology and for developing very early diagnostic tools. Vecter flow mapping have provided valuable opportunities for direct in vivo assessment of multidirectional blood flow. Here we analyzed the LV vortex in patients with impaired LV diastolic function by vector flow mapping.Methods:Patients with LV diastolic dysfunction were divided into 3 groups:impaired LV relaxation(n=39), PNF(n=39) and restrictive LV filling (n=29). Healthy participants were identified as controls(n=22). All patients underwent 2D, M model and doppler echocardiography.Left ventricular inflow color Doppler findings were analyzed by the vector profile model with the vector flow mapping technology offline. Left ventriculer end diastolic pressure was measured by left cardiac catheterization in 23 patients.Results:①Duration of vortex during early diastole among restrictive LV filling and PNF group were significantly higher than that of impaired LV relaxation and control group (P<0.05, respectively). Duration of vortex during early diastole in restrictive LV filling group was significantly higher than that of PNF group(P<0.05). But duration of vortex during late diastole had no significant difference. Maximum vortex area during eraly diastole and late diastole among (P<0.05, respectively). Diastolic mean energy loss(EL) in control group, impaired LV relaxation, PNF and restrictive LV filling group gradually increased (P<0.05, respectively).② Diastolic mean EL was positively correlated with left ventricular end diatolic diameter, left ventricular end diatolic volume, left atrial diameter and left atrial volume index(r=0.5237, P<0.05; r=0.8022, P<0.05; r=0.7167, P<0.05; r=0.7572, P<0.05). Diastolic mean EL was positively correlated with E and E/A(r=0.5237, P<0.05; r=0.6487, P<0.05). but negtively correlated with A and e’(r=-0.4673, P<0.05; r=-0.6927, P<0.05).③Diastolic mean EL was positively correlated with E/e’(r=0.7466, P<0.05).V Diastolic mean EL was positively correlated with Left ventriculer end diastolic pressure measured by left cardiac catheterization (r= 0.8612, P< 0.05).Conclusion:VFM can be used to access vortex flow in patients with left ventricular diastolic dysfunction. Duration of vortex during diastole is the effective index in evaluation of vortex flow generation and evolution. Diastolic mean EL is a new parameter for left ventricular diastolic function and LV filling pressure assessment.