Department of Mechanical Engineering, University of Texas at Austin, Austin, TX, USA.
Division of Cardiothoracic Surgery, Spectrum Health, Grand Rapids, MI, USA.
Biomech Model Mechanobiol. 2019 Oct;18(5):1351-1361. doi: 10.1007/s10237-019-01148-y. Epub 2019 Apr 12.
The tricuspid leaflets coapt during systole to facilitate proper valve function and, thus, ensure efficient transport of deoxygenated blood to the lungs. Between their open state and closed state, the leaflets undergo large deformations. Quantification of these deformations is important for our basic scientific understanding of tricuspid valve function and for diagnostic or prognostic purposes. To date, tricuspid valve leaflet strains have never been directly quantified in vivo. To fill this gap in our knowledge, we implanted four sonomicrometry crystals per tricuspid leaflet and six crystals along the tricuspid annulus in a total of five sheep. In the beating ovine hearts, we recorded crystal coordinates alongside hemodynamic data. Once recorded, we used a finite strain kinematic framework to compute the temporal evolutions of area strain, radial strain, and circumferential strain for each leaflet. We found that leaflet strains were larger in the anterior leaflet than the posterior and septal leaflets. Additionally, we found that radial strains were larger than circumferential strains. Area strains were as large as 97% in the anterior leaflet, 31% in the posterior leaflet, and 31% in the septal leaflet. These data suggest that tricuspid valve leaflet strains are significantly larger than those in the mitral valve. Should our findings be confirmed they could suggest either that the mechanobiological equilibrium of tricuspid valve resident cells is different than that of mitral valve resident cells or that the mechanotransductive apparatus between the two varies. Either phenomenon may have important implications for the development of tricuspid valve-specific surgical techniques and medical devices.
三尖瓣叶瓣在收缩期相互靠拢，以促进瓣膜的正常功能，从而确保含氧不足的血液有效地输送到肺部。在它们的开放状态和关闭状态之间，瓣叶会经历很大的变形。这些变形的定量对于我们对三尖瓣功能的基本科学理解以及诊断或预后目的都很重要。迄今为止，三尖瓣瓣叶的应变从未在体内被直接量化过。为了填补我们知识中的这一空白，我们在每片三尖瓣叶上植入了四个声纳微测计晶体，在三尖瓣环上共植入了六个晶体，总共在五只羊身上进行了实验。在跳动的羊心实验中，我们记录了晶体坐标以及血液动力学数据。记录完成后，我们使用有限应变运动学框架计算了每个瓣叶的面积应变、径向应变和周向应变的时间演变。我们发现，前瓣叶的应变比后瓣叶和隔瓣叶大。此外，我们还发现，径向应变比周向应变大。前瓣叶的面积应变高达 97%，后瓣叶为 31%，隔瓣叶为 31%。这些数据表明，三尖瓣瓣叶的应变明显大于二尖瓣瓣叶的应变。如果我们的发现得到证实，这可能表明三尖瓣瓣膜固有细胞的力学生物学平衡与二尖瓣瓣膜固有细胞不同，或者两种瓣膜之间的力学转导装置不同。这两种现象都可能对开发特定于三尖瓣的手术技术和医疗设备具有重要意义。
