Vortical Structures in Cardiac Filling Flows – A Universal Descriptor of Diastolic Efficiency – In-Vitro and Clinical Studies

Maximal efficiency of cardiac filling requires that blood entering the LV decelerate and mix evenly before energy is spent. This requires a rapid rollup of the flowing blood into the vortical structures within the left ventricle. The strength and efficiency of vortex rollup can be measured in terms of the maximum amount of the circulation attained by the vortex during the formation process. Formation number, a descriptor of vortex formation, in its non-dimensional form (f = ut/D, where u = mean velocity over inflow period, t = inflow period, D = mitral annulus diameter) would be expected to stay within a narrow range. We performed both in vitro and clinical studies to quantify this parameter.