Tricuspid annuloplasty is a surgical procedure that cinches the valve's annulus in order to reduce regurgitant blood flow. One of its critical parameters is the degree of downsizing. To provide insight into the effect of downsizing, we studied the annulus of healthy sheep during suture annuloplasty. To this end, we implanted fiduciary markers along the annulus of sheep and subsequently performed a DeVega suture annuloplasty. We performed five downsizing steps in each animal while recording hemodynamic and sonomicrometry data in beating hearts. Subsequently, we used splines to approximate the annulus at baseline and at each downsizing step. Based on these approximations we computed clinical metrics of annular shape and dynamics, and the continuous field metrics height, strain, and curvature. With these data, we demonstrated that annular area reduction during downsizing was primarily driven by compression of the anterior annulus. Similarly, reduction in annular dynamics was driven by reduced contractility in the anterior annulus. Finally, changes in global height and eccentricity of the annulus could be explained by focal changes in the continuous height profile and changes in annular curvature. Our findings are important as they provide insight into a regularly performed surgical procedure and may inform the design of transcatheter devices that mimic suture annuloplasty.

中文翻译：

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缩小尺寸对正常三尖瓣环的影响。

三尖瓣环成形术是一种收紧瓣膜环以减少回流血流的外科手术。其关键参数之一是小型化程度。为了深入了解缩小尺寸的影响，我们研究了健康羊在缝合瓣环成形术期间的瓣环。为此，我们沿着绵羊的瓣环植入了信托标记，随后进行了 DeVega 缝合瓣环成形术。我们对每只动物进行了五个缩小尺寸的步骤，同时记录跳动心脏的血流动力学和声学测量数据。随后，我们使用样条曲线来近似基线和每个缩小尺寸步骤的环面。基于这些近似值，我们计算了环形形状和动力学的临床指标，以及连续场指标的高度、应变和曲率。通过这些数据，我们证明了缩小尺寸期间环面积的减少主要是由前环的压缩驱动的。类似地，环动力学的降低是由前环的收缩性降低引起的。最后，环空的整体高度和偏心率的变化可以通过连续高度轮廓的焦点变化和环空曲率的变化来解释。我们的研究结果很重要，因为它们提供了对定期进行的外科手术的深入了解，并可能为模仿缝合瓣环成形术的经导管装置的设计提供信息。