Title: Hemodynamics of a Bileaflet Mechanical Heart Valve with Different Levels of Dysfunction,
Abstract: Heart disease is one of leading causes of mortality worldwide. Healthy heart
valves are key for proper heart function. When these valves dysfunction, a
replacement is often necessary in severe cases. The current study presents an
investigation of the pulsatile blood flow through a bileaflet mechanical heart
valve (BMHV) where one leaflet is healthy and can fully open and the other
leaflet cannot fully open with different levels of dysfunction. To better
understand the implications that a dysfunctional leaflet has on the blood flow
through these valves, analysis of flow characteristics such as velocity,
pressure drop, wall shear stress and vorticity profiles was performed. Results
suggested that leaflet dysfunction caused increased local velocities,
separation regions and wall shear stresses. For example, the maximum velocity
increased from 2.53 m/s to 4.9 m/s when dysfunction increased from 0% to 100%.
The pressure drop increased (by up to 300%) with dysfunctionality. Results
suggested that leaflet dysfunction also caused increased wall shear stresses on
the valve frame where higher stresses developed around the hinges (at 75% and
100% dysfunctions). Analysis also showed that increased dysfunctionality of one
leaflet led to higher net shear forces on both the healthy and dysfunctional
leaflets (by up to 200% and 600%, respectively).