Evaluation of diastolic blood flow dynamic of the left ventricle in dogs with mitral valve regurgitation using vector flow mapping

Mitral valve regurgitation (MVR) is a common valvular disease in dogs. Hydrokinetic evaluation of the blood flow within the ventricles has become possible by vector flow mapping (VFM), which shows the blood flow within the ventricles in vector and vortex flows. Blood flow within the left ventricle of MVR dogs was compared at different stages of MVR and to that of normal dogs. 14 normal dogs and 40 clinical cases of MVR were used. Echocardiographic videos were collected and vectors and vortexes were analysed by VFM analysis using software. In diastole, reversal of vectors which formed vortexes was observed around the anterior leaflet of the mitral valve in the control group. In the MVR dogs, in addition to that, reversed vectors were also observed at the left ventricular free-wall which formed Vortexes along the Posterior Wall (PWv). As MVR became more severe, PWv occupied a wider range; however, it was not observed at the outflow tract, suggesting that it occurs to lower transfer effectiveness. Controlling transfer effectiveness may be considered to alleviate the exacerbation of the heart failure caused by MVR.