Mitral valve geometrical echocardiographic analysis and 3D computational modeling of a normal mitral valve - supplementary material

<b>Aim: </b>This research aims to develop a consistent computational model of a normal mitral valve (MV) and describe mitral regurgitation (MR) geometry based on Carpentier’s classification. <b>Materials &amp;methods:</b>MV geometry was assessed by 2D transthoracic echocardiogram in 100 individuals. A 3D parametric geometric model of the MV was developed. A computational model of a normal MV was performed. <b>Results: </b>The simulation of the valve function was successfully accomplished and its kinematics was analyzed. Differences in geometry were revealed between normal and type III MR. <b>Conclusion: </b>3D computational models of the normal MV can be constructed relying on standard measurements performed by 2D echocardiography. Certain geometrical differences exist among the normal and the most severe type of MR.<b>Plain language summary: </b>Mitral insufficiency, represents the most common form of valvular heart disease and occurs when the mitral valve does not close tight causing blood to flow the wrong way in the heart. The simplest and most usual method to evaluate this dysfunction is the 2D transthoracic echocardiography, which uses ultrasound to create images of the heart. Mitral insufficiency can be classified into three types. This study tried to evaluate any differences in the clinical and<b>/</b>or echocardiographic geometrical characteristics between the normal MV and the three types of insufficient MV. Moreover, it tried to develop a 3D model to simulate the normal MV function. To achieve this, it enrolled 100 individuals (both normal and insufficientMV), evaluated theirMV with 2D echocardiography and compared all geometrical characteristics between them. Finally, computational simulation, using specific and appropriate methods, was used to create the 3D model. Regarding the results, the most differences were found between subjects with normal and subjects with type III mitral insufficiency. Moreover, a 3D model of the normal MV was successfully developed. To conclude, there are specific geometrical differences among the normal and the most severe type of the insufficient MV, while 3D models of the normal MV can be developed by 2D echocardiography measurements.

**研究目的**：本研究旨在构建一致性正常二尖瓣（mitral valve, MV）计算模型，并基于卡彭蒂耶（Carpentier）分型描述二尖瓣反流（mitral regurgitation, MR）的几何特征。**材料与方法**：本研究对100名受试者采用二维经胸超声心动图评估二尖瓣几何形态，构建了二尖瓣的三维参数化几何模型，并完成了正常二尖瓣的计算模型搭建。**研究结果**：成功完成瓣膜功能仿真并分析了其运动学特征；揭示了正常二尖瓣与Ⅲ型二尖瓣反流之间的几何形态差异。**研究结论**：可基于二维超声心动图的标准测量数据构建正常二尖瓣的三维计算模型；正常二尖瓣与最严重类型的二尖瓣反流之间存在特定的几何形态差异。**通俗语言总结**：二尖瓣关闭不全是最常见的心脏瓣膜疾病，当二尖瓣无法完全闭合时，血液会在心脏内逆向流动。评估该功能障碍最简便且常用的方法是二维经胸超声心动图，该技术借助超声生成心脏影像。二尖瓣关闭不全可分为三种类型。本研究旨在对比正常二尖瓣与三类功能不全二尖瓣的临床及/或超声心动图几何特征差异，并尝试构建模拟正常二尖瓣功能的三维模型。为此，本研究纳入100名受试者（含正常受试者与二尖瓣功能不全受试者），采用二维超声心动图评估其二尖瓣形态，并对比各组间的所有几何特征；最终通过特定适配方法完成计算仿真，构建出正常二尖瓣的三维模型。研究结果显示，正常受试者与Ⅲ型二尖瓣关闭不全受试者之间的几何形态差异最为显著。综上，正常二尖瓣与最严重类型的二尖瓣关闭不全之间存在特定几何差异，且可通过二维超声心动图测量数据构建正常二尖瓣的三维模型。