Division of Cardiothoracic Surgery, Spectrum Health, Grand Rapids, Michigan; Department of Cardiac, Vascular and Endovascular Surgery and Transplantology, Medical University of Silesia in Katowice, Silesian Centre for Heart Diseases, Zabrze, Poland.
Division of Cardiothoracic Surgery, Spectrum Health, Grand Rapids, Michigan; Department of Cardiac Surgery, Medical University of Silesia, School of Medicine in Katowice, Katowice, Poland.
Semin Thorac Cardiovasc Surg. 2021;33(2):356-364. doi: 10.1053/j.semtcvs.2020.09.012. Epub 2020 Sep 23.
Functional tricuspid regurgitation (FTR) is thought to arise due to annular dilation and alteration of right ventricular (RV) geometry in the presence of normal leaflets, yet mitral leaflets have been shown to remodel significantly in functional mitral regurgitation. We set out to evaluate tricuspid valve anterior leaflet deformations in ovine FTR. Eleven animals (FTR group) underwent implantation of a pacemaker with high rate pacing to induce biventricular dysfunction and at least moderate TR. Subsequently, both FTR (n = 11) and Control (n = 12) animals underwent implantation of 6 sonomicrometry crystals around the tricuspid annulus, 4 on the anterior leaflet, and 14 on RV epicardium. Tricuspid valve geometry and anterior leaflet strains were calculated from crystal coordinates. Left ventricular ejection fraction and RV fractional area change were significantly lower in FTR animals versus Control. Tricuspid annular area, septo-lateral diameter, RV pressures were all significantly greater in the FTR group. Mean TR grade (+0-3) was 0.7 ± 0.5 in Control and 2.4 ± 0.5 in FTR (P = < 0.001). The anterior leaflet area and length increased significantly. Global radial leaflet strain was significantly lower in FTR mostly driven by decreased free edge leaflet strain. Global circumferential anterior leaflet strain was also significantly lower in FTR with more remarkable reduction in the belly region. Rapid ventricular pacing in sheep resulted in a clinically pertinent model of RV and annular dilation with FTR and leaflet enlargement. Both circumferential and radial anterior leaflet strains were significantly reduced with FTR. Functional TR may be associated with alteration of leaflet mechanical properties.
功能性三尖瓣反流（FTR）被认为是由于正常瓣叶存在时的瓣环扩张和右心室（RV）几何形状改变引起的，但功能性二尖瓣反流时已经显示出二尖瓣瓣叶有明显的重塑。我们旨在评估羊 FTR 中三尖瓣前瓣叶的变形。11 只动物（FTR 组）接受了起搏器的高频率起搏植入，以诱导双心室功能障碍和至少中度 TR。随后，FTR 组（n=11）和对照组（n=12）动物都在三尖瓣环周围植入了 6 个超声心动图晶体，前瓣叶 4 个，右心室心外膜 14 个。从晶体坐标计算三尖瓣几何形状和前瓣叶应变。与对照组相比，FTR 动物的左心室射血分数和 RV 射血分数明显降低。三尖瓣环面积、隔侧-外侧直径、RV 压力在 FTR 组均显著增大。对照组的平均 TR 分级（0-3）为 0.7±0.5，FTR 组为 2.4±0.5（P<0.001）。前瓣叶面积和长度显著增加。FTR 组的整体径向瓣叶应变明显降低，主要是游离缘瓣叶应变降低所致。FTR 组的整体环形前瓣叶应变也明显降低，腹侧区域的降低更为显著。绵羊快速心室起搏导致 RV 和瓣环扩张以及瓣叶增大的具有临床相关性的 FTR 模型。FTR 时环形和径向前瓣叶应变均明显降低。功能性 TR 可能与瓣叶机械特性的改变有关。
