Fumero R, Pietrabissa R
J Biomech. 1986;19(1):71-7. doi: 10.1016/0021-9290(86)90110-7.
The diameter of prosthetic heart valves is usually chosen according to the anatomic annulus size as determined during open-heart surgery. Therefore, this approach does not take into account the dimensional changes induced by heart pathology and surgical procedures. In addition, current practice fails to consider the variations of heart dimensions due to hemodynamic improvement following valve replacement. Here we suggest a method to determine the appropriate prosthesis diameter according to the hemodynamic features of the patient, to its kind of activity, and to the type of prosthesis. Assuming that the pressure drop across a valve can be calculated as delta p = apv 2/2, and considering the variation of blood flow with time and its change induced by frequency, it is possible to obtain the relationship between pressure drop and prosthetic valve diameter. The results obtained with this analytical method have been plotted on diagrams which allow the graphical determination of the proper valve diameter.
人工心脏瓣膜的直径通常根据心脏直视手术中确定的解剖瓣环大小来选择。因此，这种方法没有考虑到心脏病变和手术操作引起的尺寸变化。此外，目前的做法没有考虑到瓣膜置换后血流动力学改善导致的心脏尺寸变化。在此，我们提出一种根据患者的血流动力学特征、活动类型和假体类型来确定合适假体直径的方法。假设瓣膜两端的压力降可以计算为Δp = apv²/2，并考虑血流随时间的变化及其由频率引起的变化，就有可能获得压力降与人工瓣膜直径之间的关系。用这种分析方法得到的结果已绘制在图表上，这些图表可用于通过图形确定合适的瓣膜直径。
