PHEniX Laboratory, Department of Pulmonary Medicine, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; Pulmonary Hypertension and Thrombosis, Amsterdam Cardiovascular Sciences, Amsterdam, the Netherlands.
Cardiovascular and Respiratory Physiology, Faculty of Science and Technology, Technical Medical Centre, University of Twente, Enschede, the Netherlands.
J Am Coll Cardiol. 2023 Aug 22;82(8):704-717. doi: 10.1016/j.jacc.2023.05.063.
Precapillary pulmonary hypertension (precPH) patients have altered right atrial (RA) function and right ventricular (RV) diastolic stiffness.
This study aimed to investigate RA function using pressure-volume (PV) loops, isolated cardiomyocyte, and histological analyses.
RA PV loops were constructed in control subjects (n = 9) and precPH patients (n = 27) using magnetic resonance and catheterization data. RA stiffness (pressure rise during atrial filling) and right atrioventricular coupling index (RA minimal volume / RV end-diastolic volume) were compared in a larger cohort of patients with moderate (n = 39) or severe (n = 41) RV diastolic stiffness. Cardiomyocytes were isolated from RA tissue collected from control subjects (n = 6) and precPH patients (n = 9) undergoing surgery. Autopsy material was collected from control subjects (n = 6) and precPH patients (n = 4) to study RA hypertrophy, capillarization, and fibrosis.
RA PV loops showed 3 RA cardiac phases (reservoir, passive emptying, and contraction) with dilatation and elevated pressure in precPH. PrecPH patients with severe RV diastolic stiffness had increased RA stiffness and worse right atrioventricular coupling index. Cardiomyocyte cross-sectional area was increased 2- to 3-fold in precPH, but active tension generated by the sarcomeres was unaltered. There was no increase in passive tension of the cardiomyocytes, but end-stage precPH showed reduced number of capillaries per mm accompanied by interstitial and perivascular fibrosis.
RA PV loops show increased RA stiffness and suggest atrioventricular uncoupling in patients with severe RV diastolic stiffness. Isolated RA cardiomyocytes of precPH patients are hypertrophied, without intrinsic sarcomeric changes. In end-stage precPH, reduced capillary density is accompanied by interstitial and perivascular fibrosis.
毛细血管前肺动脉高压（precPH）患者的右心房（RA）功能和右心室（RV）舒张僵硬发生改变。
本研究旨在使用压力-容积（PV）环、分离的心肌细胞和组织学分析来研究 RA 功能。
使用磁共振和导管数据在对照受试者（n=9）和 precPH 患者（n=27）中构建 RA PV 环。在更大的中度（n=39）或重度（n=41）RV 舒张僵硬患者队列中比较 RA 僵硬（心房充盈期间压力升高）和右房-室耦合指数（RA 最小容积/RV 舒张末期容积）。从接受手术的对照受试者（n=6）和 precPH 患者（n=9）的 RA 组织中分离心肌细胞。从对照受试者（n=6）和 precPH 患者（n=4）的尸检材料中收集 RA 肥大、毛细血管化和纤维化的标本。
RA PV 环显示 3 个 RA 心脏阶段（储器、被动排空和收缩），precPH 出现扩张和升高的压力。RV 舒张僵硬严重的 precPH 患者的 RA 僵硬增加，右房-室耦合指数更差。precPH 中的心肌细胞横截面积增加了 2-3 倍，但肌节产生的主动张力没有改变。心肌细胞的被动张力没有增加，但终末期 precPH 显示每毫米毛细血管数量减少，伴有间质和血管周围纤维化。
RA PV 环显示 RA 僵硬增加，提示严重 RV 舒张僵硬患者的房室分离。precPH 患者的分离 RA 心肌细胞发生肥大，而肌节无内在变化。在终末期 precPH 中，毛细血管密度降低，伴有间质和血管周围纤维化。
