Meijer Heart and Vascular Institute at Spectrum Health, 100 Michigan Ave NE, Grand Rapids, MI 49503, USA; Department of Cardiac Surgery, Medical University of Silesia, School of Medicine in Katowice, Ziołowa 47, 40635 Katowice, Poland.
Meijer Heart and Vascular Institute at Spectrum Health, 100 Michigan Ave NE, Grand Rapids, MI 49503, USA.
Int J Cardiol. 2018 Aug 1;264:124-129. doi: 10.1016/j.ijcard.2018.02.072.
Functional tricuspid regurgitation (FTR) commonly arises secondary to conditions affecting the left heart and is associated with right ventricular dysfunction and tricuspid annular dilatation. We set out to establish an animal model of acute RV failure (RVF) with FTR resembling the clinical features.
Ten adult sheep had pressure sensors placed in the LV, RV, and right atrium while sonomicrometry crystals were implanted around tricuspid annulus and on the RV. Animals were studied open-chest to assess for RV function and FTR after: (1) volume infusion, (2) pulmonary artery constriction, (3) 5 min posterior descending artery occlusion, and (4) combination of all interventions. Hemodynamic, echocardiographic, and sonomicrometry data were collected at baseline and after every intervention. RV dimensions, RV strain, and annular area, perimeter, and size were calculated from crystal coordinates. The model was validated in six additional sheep studied only before and after combined interventions.
Neither volume infusion, pulmonary hypertension, nor ischemia were associated with RVF or clinically significant TR when applied separately but combined resulted in RVF and greater than moderate FTR. In the validation group, maximal RV volume increased (62 ± 14 vs 70 ± 16 ml, p = 0.006), contractility decreased (20 ± 6 vs 12 ± 2%, p = 0.02), and strain increased. FTR increased from 0.4 ± 0.5 to 2.5 ± 0.8 (p < 0.001) and annular area from 652 ± 87 mm to 739 ± 87 mm (p = 0.005).
The developed ovine model of acute RVF was associated with significant annular and RV enlargement and FTR. This novel and clinically pertinent research platform offers insight into the acute RVF pathophysiology and can be utilized to evaluate treatment interventions.
功能性三尖瓣反流（FTR）通常继发于影响左心的疾病，与右心室功能障碍和三尖瓣环扩张有关。我们旨在建立一种具有类似于临床特征的 FTR 的急性 RV 衰竭（RVF）动物模型。
10 只成年绵羊在左心室、右心室和右心房放置压力传感器，在三尖瓣环周围和右心室放置超声心动图晶体检波器。动物开胸进行 RV 功能和 FTR 评估，在以下情况下：（1）容量输注，（2）肺动脉收缩，（3）5 分钟后降支动脉闭塞，（4）所有干预的组合。在基线和每次干预后收集血流动力学、超声心动图和超声心动图数据。从晶体检波器坐标计算 RV 尺寸、RV 应变和环面积、周长和大小。在仅在联合干预前后进行研究的另外 6 只绵羊中验证了该模型。
单独应用容量输注、肺动脉高压或缺血均与 RVF 或临床上显著的 TR 无关，但联合应用会导致 RVF 和大于中度的 FTR。在验证组中，最大 RV 容积增加（62±14 与 70±16ml，p=0.006），收缩力降低（20±6 与 12±2%，p=0.02），应变增加。FTR 从 0.4±0.5 增加到 2.5±0.8（p<0.001），环面积从 652±87mm 增加到 739±87mm（p=0.005）。
所开发的急性 RVF 绵羊模型与显著的环形和 RV 增大和 FTR 相关。这种新颖且与临床相关的研究平台提供了对急性 RVF 病理生理学的深入了解，并可用于评估治疗干预措施。
