Comparison of Hemodynamic Performance, Three-Dimensional Flow Fields, and Turbulence Levels for Three Different Heart...

The hemodynamic performance of different prosthetic heart valves is difficult to compare among studies due to a variety of test conditions and experimental techniques. Existing studies are typically limited to one family of valves (biological or mechanical) and testing conditions of 5l/min and often lack sufficient spatial resolution. To address these limitations, a pulse duplicator with a multi-view imaging system (Tomo-PIV) was employed to investigate the three-dimensional flow field in the aortic root of three different valves: a tri-leaflet mechanical heart valve (TRIFLO, Novostia), a bi-leaflet mechanical heart valve (On-X, Artivion), and a biological heart valve (Perimount, Edwards Lifesciences). The valves were tested at low (3 l/min), normal (5 l/min), and elevated (7 l/min) cardiac output $$ under hypotensive (40/60mmHg), normotensive (80/120mmHg), and moderate hypertensive (105/170mmHg) pressure conditions, respectively. Compared to the Perimount, peak mean velocity was - 33%, - 24%, - 18% for the TRIFLO and - 32%, - 20%, - 11% for the On-X at low, moderate, and elevated $$ , respectively. Corresponding peak $$ values decreased by - 66%, - 57%, - 44% (TRIFLO) and - 60%, - 50%, - 36% (On-X). At low $$ , $$ was lower for Perimount (1.07cm²) than for TRIFLO (1.47cm²) and On-X (1.52cm²), while it increased for elevated $$ to 2.75cm² (TRIFLO) and 2.16cm² (Perimount and On-X). For all valves, increasing $$ led to increased flow velocities, higher $$ and higher levels of turbulence, and the spatial influence of the valve on the flow field in the ascending aorta was extended. $$ peaked closer to the STJ than for TRIFLO and Perimount.