Evaluating the Effect of Subaortic Stenosis on Blood Fow Downstream of Bileaflet Mechanical Heart Valve Using Particle Image Velocimetry.*

Concomitant left ventricular septal myectomy during aortic valve replacement is possible in the presence of congenital or acquired severe subaortic stenosis. However, subaortic stenosis may recur in some patients (recurrence rate up to 37%), so regular clinical evaluation is required. The hemodynamic effects of different types (discrete vs. tunnel) and shapes (symmetric vs. asymmetric) of subaortic stenosis on flow downstream of bileaflet mechanical heart valve were investigated in this study using particle image velocimetry and a cutting-edge cardiac simulator. Different 3D printed subaortic stenosis models were created and tested under physiological flow conditions for this purpose.

The study found that subaortic stenosis and its various types and shapes had a significant impact on flow patterns in terms of velocity, vorticity dynamics, and Reynolds shear stress. Also, leaflets’ kinematics were noticeably affected by the type, shape, and severity of subaortic stenosis.