Hopmeyer J, Fontaine A A, Yang S, Levine R A, Yoganathan A P
Cardiovascular Fluid Mechanics Laboratory, School of Chemical Engineering, Georgia Institute of Technology, Atlanta 30332-0100, USA.
J Am Soc Echocardiogr. 1996 Jan-Feb;9(1):44-57. doi: 10.1016/s0894-7317(96)90103-0.
The effect of aortic outflow on the quantification of mitral regurgitation by the flow convergence method was investigated by both in vitro experiments and computational simulations. Digital analysis of the color Doppler M-mode images was compared with results obtained with laser Doppler anemometry, an engineering gold standard, and three-dimensional computational simulations. Regurgitant orifices of 3.2 and 6.4 mm in diameter were used with instantaneous aortic flow rates from 0 to 500 ml/sec, corresponding to net cardiac outputs of 0 to 5 L/min. In the absence of aortic outflow, a clear plateau was observed in plots of the calculated flow rate as a function of the distance from the orifice, indicating that there was a zone in which the hemispheric assumption was valid. As the aortic outflow was increased, the length of this plateau region decreased and then disappeared at high aortic flow rates. Farther from the orifice, beyond the plateau zone, the flow rate was overestimated and this overestimation increased with increasing aortic flow rate. Results showed excellent agreement between in vitro experiments and computational stimulations. This study demonstrated that aortic outflow has a dramatic effect on the flow convergence region and therefore must be considered in flow rate calculations.
通过体外实验和计算模拟研究了主动脉流出对用血流会聚法量化二尖瓣反流的影响。将彩色多普勒M型图像的数字分析结果与激光多普勒风速仪（一种工程学金标准）以及三维计算模拟所获得的结果进行了比较。使用直径为3.2毫米和6.4毫米的反流口，瞬时主动脉流速为0至500毫升/秒，对应于心输出量为0至5升/分钟。在没有主动脉流出的情况下，计算流速作为距反流口距离的函数的图中观察到一个明显的平台期，表明存在一个半球形假设有效的区域。随着主动脉流出增加，该平台期区域的长度减小，然后在高主动脉流速时消失。在距反流口更远的地方，超出平台期区域，流速被高估，并且这种高估随着主动脉流速的增加而增加。结果表明体外实验和计算模拟之间具有极好的一致性。这项研究表明主动脉流出对血流会聚区域有显著影响，因此在流速计算中必须予以考虑。
