Charles University in Prague, Faculty of Mathematics and Physics, Prague, Czech Republic Stenotic heart valve diseases are among the leading causes of death worldwide. A stenosis in the cardiovascular system is a reduction in cross-sectional area of a structure across which blood flows due to the plack or other incapabillities. Interventional and surgical treatments have provided improvements in survival, cardiac function, and functional capacity. Still, accurate and precise assessment of stenosis severity is required in order to appropriately decide whether and what type of treatment is warranted for a given lesion. Current approaches to interpreting non-invasive data are still incapable of ascertaining hemodynamic stenosis severity. Various methods have been used to evaluate stenoses by either anatomic or physiologic criteria. In this work, we develop an improved approach to determination of blood energy dissipation and pressure differences across cardiovascular stenoses, which can be applied to non-invasive diagnostic modalities. Even if we consider incompressible newtonian fluid in rigid wall, the problem is quite challenging. We will start with the flow in different geometries of the stenotic vessels to obtain the reference velocity field and pressure drop across the stenosis and compute corresponding dissipation. Finally, we discuss two approaches to obtain pressure from the measured velocity.