Venet Maelys, Malik Aimen, Gold Samantha, Zhang Naiyuan, Gopaul Josh, Dauz John, Yazaki Kana, Ponzoni Matteo, Coles John G, Maynes Jason T, Sun Mei, Howell Alison, Chaturvedi Rajiv, Mertens Luc, Mroczek Dariusz, Uike Kiyoshi, Baranger Jerome, Friedberg Mark K, Villemain Olivier
Department of Cardiology, The Labatt Family Heart Centre, The Hospital for Sick Children, Toronto, Ontario, Canada; Bordeaux University Hospital, Department of Pediatric and Adult Congenital Cardiology, Pessac, France; Electrophysiology and Heart Modeling Institute, Institut Hospital-Universitaire Liryc, Fondation Bordeaux Université, Bordeaux, France.
Department of Cardiology, The Labatt Family Heart Centre, The Hospital for Sick Children, Toronto, Ontario, Canada.
JACC Cardiovasc Imaging. 2025 Feb;18(2):211-225. doi: 10.1016/j.jcmg.2024.06.020. Epub 2024 Aug 21.
Right ventricular (RV) hemodynamic performance determines the prognosis of patients with RV pressure overload. Using ultrafast ultrasound, natural wave velocity (NWV) induced by cardiac valve closure was proposed as a new surrogate to quantify myocardial stiffness.
This study aimed to assess RV NWV in rodent models and children with RV pressure overload vs control subjects and to correlate NWV with RV hemodynamic parameters.
Six-week-old rats were randomized to pulmonary artery banding (n = 6), Sugen hypoxia-induced pulmonary arterial hypertension (n = 7), or sham (n = 6) groups. They underwent natural wave imaging, echocardiography, and hemodynamic assessment at baseline and 6 weeks postoperatively. The authors analyzed NWV after tricuspid and after pulmonary valve closure (TVC and PVC, respectively). Conductance catheters were used to generate pressure-volume loops. In parallel, the authors prospectively recruited 14 children (7 RV pressure overload; 7 age-matched control subjects) and compared RV NWV with echocardiographic and invasive hemodynamic parameters.
NWV significantly increased in RV pressure overload rat models (4.99 ± 0.27 m/s after TVC and 5.03 ± 0.32 m/s after PVC in pulmonary artery banding at 6 weeks; 4.89 ± 0.26 m/s after TVC and 4.84 ± 0.30 m/s after PVC in Sugen hypoxia at 6 weeks) compared with control subjects (2.83 ± 0.15 m/s after TVC and 2.72 ± 0.34 m/s after PVC). NWV after TVC correlated with both systolic and diastolic parameters including RV dP/dt (r = 0.75; P < 0.005) and RV Ees (r = 0.81; P < 0.005). NWV after PVC correlated with both diastolic and systolic parameters and notably with RV end-diastolic pressure (r = 0.65; P < 0.01). In children, NWV after both right valves closure in RV pressure overload were higher than in healthy volunteers (P < 0.01). NWV after PVC correlated with RV E/E' (r = 0.81; P = 0.008) and with RV chamber stiffness (r = 0.97; P = 0.03).
Both RV early-systolic and early-diastolic myocardial stiffness show significant increase in response to pressure overload. Based on physiology and our observations, early-systolic myocardial stiffness may reflect contractility, whereas early-diastolic myocardial stiffness might be indicative of diastolic function.
右心室（RV）血流动力学表现决定了右心室压力超负荷患者的预后。利用超快超声，心脏瓣膜关闭诱发的自然波速度（NWV）被提议作为量化心肌僵硬度的新替代指标。
本研究旨在评估啮齿动物模型和右心室压力超负荷儿童与对照受试者的右心室NWV，并将NWV与右心室血流动力学参数相关联。
将6周龄大鼠随机分为肺动脉环扎组（n = 6）、苏金缺氧诱导的肺动脉高压组（n = 7）或假手术组（n = 6）。在基线和术后6周对它们进行自然波成像、超声心动图和血流动力学评估。作者分析了三尖瓣关闭后和肺动脉瓣关闭后（分别为TVC和PVC）的NWV。使用导管生成压力-容积环。同时，作者前瞻性招募了14名儿童（7名右心室压力超负荷；7名年龄匹配的对照受试者），并将右心室NWV与超声心动图和有创血流动力学参数进行比较进行比较。
与对照受试者（TVC后2.83±0.15 m/s，PVC后2.72±0.34 m/s）相比，右心室压力超负荷大鼠模型中的NWV显著增加（肺动脉环扎6周时TVC后4.99±0.27 m/s，PVC后5.03±0.32 m/s；苏金缺氧6周时TVC后4.89±0.26 m/s，PVC后4.84±0.30 m/s）。TVC后的NWV与收缩期和舒张期参数均相关，包括右心室dP/dt（r = 0.75；P < 0.005）和右心室Ees（r = 0.81；P < 0.005）。PVC后的NWV与舒张期和收缩期参数均相关，尤其与右心室舒张末期压力相关（r = 0.65；P < 0.01）。在儿童中，右心室压力超负荷时右心室两个瓣膜关闭后的NWV均高于健康志愿者（P < 0.01）。PVC后的NWV与右心室E/E'（r = 0.81；P = 0.008）和右心室腔僵硬度（r = 0.97；P = 0.03）相关。
右心室收缩早期和舒张早期心肌僵硬度均因压力超负荷而显著增加。基于生理学和我们的观察，收缩早期心肌僵硬度可能反映收缩力，而舒张早期心肌僵硬度可能指示舒张功能。
