Computational analysis of ventricular valve-valve interaction: influence of flow conditions

Apart from dependence on the heart muscle contractility, the pumping efficiency of the heart depends on the functioning of its valves. Valve functionality, expressed as 1 minus the ratio between regurgitant and stroke volume, is the result of the motion of the valve depending on local flow phenomena. In this work, the relation between flow conditions and valve functionality was studied by means of a parameter study of the flow and valve dynamics in a two-dimensional computational model of the left ventricle with two rigid valves. It was found that valve functionality depends strongly on the applied flow conditions as expressed by the Strouhal and the Reynolds numbers. Furthermore, it was found that the regurgitant volume can vary from beat-to-beat resulting in a non-periodic pumping efficiency of the heart. These observations are of importance to future research based on simulations of geometrically more realistic heart valve-ventricle configurations as it may not always be taken for granted that beat-to-beat variations of the pumping efficiency are small. © 2009 Taylor & Francis.