Fluid mechanics of aortic stenosis

摘要: In vitro qualitative and quantitative flow-mapping studies were conducted in an adult size aortic flow chamber, using bioprosthetic valves (0·5–5·0 cm2) to mimic varying degrees of stenosis. The performed under physiologic conditions a left heart stimulator using: visualization, laser Doppler anemometry (LDA), continuous-wave (CW) colour mapping (CDFM) techniques. Pressure gradients the range 15–150 mmHg accurately predicted by CW Bernoulli equation (r=0·99). visualization CDFM revealed that all stenosis led jet-type fields, which jet orientation was not necessarily symmetric skewed degrees. Therefore, stenosis, measurements should be multiple views order visualize field properly. Measurements with cross-sectional LDA as increased: narrowed; peak velocity turbulent intensities increased; instability acceleration proximal valve increased. Peak velocities high 4–7 ms−1 turbulence levels (i.e. root mean square axial velocities) 1·0–2·3 measured, moderately severely stenotic valves. These elevated could cause damage formed elements blood walls ascending aorta. created valves, made interpretation recordings very difficult, if impossible.