Ph.D. Thesis Defense by Russell Heinrich

(Dr. Ajit Yoganathan, advisor)

"Assessment of the Fluid Mechanics of Aortic Valve Stenosis With In Vitro Modeling and Control Volume Analysis"

Abstract

This thesis describes experiments performed to assess the relationship between the fluid mechanics of aortic valve stenosis and left ventricular workload. In vitro experiments were performed to examine the effects that the downstream geometry and stenotic orifice area had on left ventricular work. A flexible model of the left ventricle was created to examine the effects of jet direction, ventricular wall motion and realistic valve geometries on left ventricular work. Finally, specific prosthetic valve designs, sizes and orientations were examined to determine their effects on left ventricular work.

The experiments have shown that the geometry downstream of the aortic valve is an important determinant of left ventricular workload. In addition, a critical value of the ratio of the aortic valve stenosis orifice area to the aortic cross-sectional area was identified. The left ventricular model experiments have shown that jet direction, realistic valve geometry and ventricular wall motion can have significant effects on left ventricular workload. Also, prosthetic valve design, size and orientation have important effects on the left ventricular workload.