Correlation between Aortic Flow and Coronary Circulation

Abstract

Three bi-leaflet prostheses, the St. Jude Medical (SJM) and the On-X valves with straight leaflets and the MIRA valves with curved leaflets were tested in the aortic position under pulsatile-flow condition. Dynamic PIV system, which was employed to analyze the flow field affected by the valve-installed orientations, leaflet shapes, and valve designs, and direct measurement of the coronary flow using ultrasonic flow meter were utilized to correlate the results of aortic flow field to coronary flow. Detailed chronological comparison of the flow fields downstream of the aortic valve and inside the sinus of valsalva associated with the opening, accelerating, peak, and closing phase of the flow revealed the significance of the leaflet and overall valve designs on the flow and possible influence on the coronary flow.

Based on the experimental results, following general conclusions can be made. The SJM and the newer On-X valve generate stronger circulatory flow inside the sinus of valsalva when valve orientation is set at 180°( while the MIRA valve with curved leaflet generates stronger circulatory flow inside the sinus of valsalva when valve orientation is set at 90°). Direct measurement of coronary flow clearly shows the increase of flow rate when the circulatory flow inside the sinus of valsalva increase indicating the positive correlation exist between the circulatory flow inside the sinus of valsalva and the coronary flow.