UMR-S 999, Inserm, Hôpital Marie Lannelongue, Université Paris-Sud, Université Paris-Saclay, Le Plessis-Robinson, France.
UMR-S 1180, Inserm, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France.
J Am Soc Echocardiogr. 2017 Nov;30(11):1138-1147.e4. doi: 10.1016/j.echo.2017.07.003. Epub 2017 Aug 30.
Early detection of right ventricular (RV) failure is required to improve the management of patients with congenital heart diseases. The aim of this study was to validate echocardiography for the early detection of overloaded RV dysfunction, compared with hemodynamic and myocyte contractility assessment.
Using a porcine model reproducing repaired tetralogy of Fallot, RV function was evaluated over 4 months using standard echocardiography and speckle-tracking compared with hemodynamic parameters (conductance catheter). Sarcomere shortening and calcium transients were recorded in RV isolated myocytes. Contractile reserve (ΔE) was assessed by β-adrenergic stimulation in vivo (dobutamine 5 μg/kg) and ex vivo (isoproterenol 100 nM).
Six operated animals were compared with four age- and sex-matched controls. In the operated group, hemodynamic RV efficient ejection fraction was significantly decreased (29.7% [26.2%-34%] vs 42.9% [40.7%-48.6%], P < .01), and inotropic responses to dobutamine were attenuated (ΔE was 51% vs 193%, P < .05). Echocardiographic measurements of fraction of area change, tricuspid annular plane systolic excursion, tricuspid annular peak systolic velocity (S') and RV free wall longitudinal systolic strain and strain rate were significantly decreased. Strain rate, S', and tricuspid annular plane systolic excursion were correlated with ΔE (r = 0.75, r = 0.78, and r = 0.65, respectively, P < .05). These alterations were associated in RV isolated myocytes with the decrease of sarcomere shortening in response to isoproterenol and perturbations of calcium homeostasis assessed by the increase of spontaneous calcium waves.
In this porcine model, both standard and strain echocardiographic parameters detected early impairments of RV function and cardiac reserve, which were associated with cardiomyocyte excitation-contraction coupling alterations.
需要早期检测右心室（RV）衰竭，以改善先天性心脏病患者的治疗效果。本研究旨在通过超声心动图与血流动力学和心肌收缩力评估对比，验证其对 RV 超负荷功能障碍的早期检测能力。
使用一种复制法洛四联症修复后的猪模型，在 4 个月内通过标准超声心动图和斑点追踪技术与血流动力学参数（电导导管）进行 RV 功能评估。在 RV 分离心肌细胞中记录肌节缩短和钙瞬变。通过体内（多巴酚丁胺 5μg/kg）和体外（异丙肾上腺素 100nM）β-肾上腺素刺激评估收缩储备（ΔE）。
比较了 6 只手术动物和 4 只年龄和性别匹配的对照动物。在手术组中，RV 有效射血分数明显降低（29.7%[26.2%-34%] vs 42.9%[40.7%-48.6%]，P<.01），对多巴酚丁胺的变力反应减弱（ΔE 为 51% vs 193%，P<.05）。面积变化分数、三尖瓣环平面收缩期位移、三尖瓣环收缩期峰值速度（S'）和 RV 游离壁纵向收缩应变和应变率的超声心动图测量值明显降低。应变率、S'和三尖瓣环平面收缩期位移与ΔE 相关（r=0.75、r=0.78 和 r=0.65，分别，P<.05）。这些变化与 RV 分离心肌细胞中异丙肾上腺素反应肌节缩短减少以及通过自发钙波增加评估的钙稳态紊乱相关。
在这种猪模型中，标准和应变超声心动图参数均能早期检测 RV 功能和心脏储备的损害，与心肌兴奋-收缩偶联改变相关。
