Abstract：
Computational fluid dynamics (CFD) was used to identify factors influencing the accuracy of the hemispherical proximal isovelocity surface area (PISA) method in calculating the effective regurgitant orifice area (EROA) for patients with functional mitral regurgitation (FMR). Ninety-nine CFD models were constructed to investigate the impact of regurgitant orifice shape and leaflet tethering on the EROA calculation using the PISA method. The correction factors for regurgitation orifice shape (CFs) and for leaflet tethering (CFt) were derived by comparing the 2D PISA method and the actual orifice area. The correction formula was then tested in vivo via 2D transthoracic echocardiography with 3D transesophageal echocardiography of the vena contracta area (VCA) as a reference method in 62 patients with FMR. Based on the CFD simulation results, the two major factors for correcting the EROA calculation were vena contracta length (VCL) and coaptation depth (CD). The correction formula for the EROA was corrected effective regurgitant orifice area (CEROA) = EROA*CFs*CFt, where CFs = 0.59 × VCL(cm) + 0.6 × MR Vmax(cm/s)-0.63 × PISA R(cm)-1.51 and CFt = 0.4 × CD (cm) + 0.96. The correction formula was applied to FMR patients, and the bias and LOA between the CEROA and VCA (0.01 ± 0.13 cm2) were much smaller than those between the EROA and VCA (0.26 ± 0.32 cm2). The CFD-based correction formula improves the accuracy of the EROA calculation based on the hemispheric PISA method, possibly leading to more accurate and reliable data for treatment decision-making in FMR patients.
摘要：
计算流体动力学（CFD）用于确定影响半球形近端等速表面积（PISA）方法在计算功能性二尖瓣反流（FMR）患者的有效反流孔口面积（EROA）时的准确性的因素。使用PISA方法构建了九十九个CFD模型，以研究反流孔口形状和小叶束缚对EROA计算的影响。通过比较2DPISA方法和实际孔口面积，得出了反流孔口形状（CFs）和小叶束缚（CFt）的校正因子。然后通过2D经胸超声心动图在体内测试校正公式，以62例FMR患者的静脉收缩区（VCA）的3D经食管超声心动图作为参考方法。根据CFD模拟结果,校正EROA计算的两个主要因素是静脉收缩长度(VCL)和接合深度(CD).EROA的校正公式为校正后的有效反流孔口面积(CEROA)=EROA*CFs*CFt,其中CFs=0.59×VCL(cm)+0.6×MRVmax(cm/s)-0.63×PISAR(cm)-1.51,CFt=0.4×CD(cm)+0.96。将校正公式应用于FMR患者，CEROA和VCA之间的偏差和LOA（0.01±0.13cm2）远小于EROA和VCA之间的偏差和LOA（0.26±0.32cm2）。基于CFD的修正公式提高了基于半球PISA方法的EROA计算的精度,可能为FMR患者的治疗决策提供更准确和可靠的数据。
