Left Ventricular Blood Flow Dynamics in Aortic Stenosis before and after Aortic Valve Replacement

Surgical intervention for aortic valve stenosis (AS) has been established; however its diagnosis based on echocardiographic assessment is still limited by aortic valvular velocity, aortic valvular pressure gradients, and color Doppler imaging. Echo-dynamography (EDG) is a method to determine intracardiac flow dynamics, such as two-dimensional blood flow velocity, vortex, and dynamic pressure. These flow dynamics may be influenced by left ventricular (LV) wall motion and the resistance in LV outflow caused by AS. The objective of the present study was to assess the changes and differences in LV vortices and vorticity before and after AS surgery. Five patients who underwent aortic valve replacement surgery for AS and five control patients were included. Besides routine echocardiographic measurement, EDG was applied to determine the two-dimensional blood flow vector and vorticity. The LV vortex flow in the isovolumetric contraction phase had multiple formations in preoperative cases. The clockwise vortex was found in all cases postoperatively; the vortex formation showed no significant difference between postoperative and normal control groups. EDG may serve important information on LV flow dynamics, non-invasively.