Several studies have suggested that the mitral annulus displacement and velocity in early diastole can be used as indicators
of diastolic performance. The peak velocity of the mitral annulus away from the LV apex during early diastole, which indicates
the rate of longitudinal expansion of the LV, is reduced in patients with impaired diastolic relaxation. With the intention
of relating the trans-mitral flow to mitral annulus plane dynamics, we measured mitral annulus recoil force for different
valve sizes, while applying an exponential pressure drop in a simplified model of the ventricle. The temporal changes in diameter
of the valve during rapid filling phase were also considered. The process of ventricular vortex formation was studied together
with the measurement of mitral annulus recoil force within different pressure drop conditions. Matching the vorticity contour
plots with the recoil force measurements resulted in the fact that the magnitude of recoil is maximal once the vortex ring
is about to pinch off, regardless of the valve size or the characteristics of ventricular pressure drop. This study showed
that the mitral annulus recoil is maximal once occurs at the vortex formation time ranging from 3.5 to 4.5. It was also shown
that the presence of leaflets would dissipate the annulus recoil force.
Keywords Vortex ring - Vortex formation time - Left ventricle - Diastole - Mitral annulus recoil