Significant mitral valve regurgitation creates progressive adverse remodeling of the left ventricle (LV). Replacement of the failing valve with a prosthesis generally improves patient outcomes but leaves the patient with non-physiological intracardiac flow patterns that might contribute to their future risk of thrombus formation and embolism.

It has been suggested that the angular orientation of the implanted valve might modify the postoperative distortion of the intraventricular flow field. In this study, we investigated the effect of prosthetic valve orientation on LV flow patterns by using heart geometry from a patient with LV dysfunction and a competent native mitral valve to calculate intracardiac flow fields with computational fluid dynamics (CFD). Results were validated using in vivo 4D Flow MRI. The computed flow fields were compared to calculations following virtual implantation of a mechanical heart valve oriented in four different angles to assess the effect of leaflet position. Flow patterns were visualized in long- and short-axes and quantified with flow component analysis. In comparison to a native valve, valve implantation increased the proportion of the mitral inflow remaining in the basal region and further increased the residual volume in the apical area. Only slight changes due to valve orientation were observed.

Using our numerical framework, we demonstrated quantitative changes in left ventricular blood flow due to prosthetic mitral replacement. This framework may be used to improve design of prosthetic heart valves and implantation procedures to minimize the potential for apical flow stasis, and potentially assist personalized treatment planning.

二尖瓣关闭不全明显导致左心室（LV）进行性不良重塑。用假体代替有故障的瓣膜通常可以改善患者的预后，但会使患者处于非生理性的心内血流模式，这可能会导致他们将来发生血栓形成和栓塞的风险。

已经提出，植入的瓣膜的角度取向可能会改变脑室内流场的术后变形。在这项研究中，我们通过使用左室功能不全患者的心脏几何形状和称职的天然二尖瓣来研究人工瓣膜方向对左心室血流模式的影响，并通过计算流体力学（CFD）计算心脏内流场。使用体内验证结果4D流MRI。将虚拟流向四个不同角度的机械心脏瓣膜虚拟植入后，将计算得到的流场与计算结果进行比较，以评估小叶位置的影响。流动模式在长轴和短轴上可视化，并通过流动成分分析进行量化。与天然瓣膜相比，瓣膜植入增加了残留在基底区域的二尖瓣血流的比例，并进一步增加了根尖区域的残留量。仅观察到由于阀方向的轻微变化。

使用我们的数值框架，我们证明了由于人工二尖瓣置换术导致左心室血流的定量变化。该框架可用于改善人工心脏瓣膜和植入程序的设计，以最大程度地减少根尖血流淤滞的可能性，并可能有助于个性化治疗计划。