Delhaas Tammo, Koeken Yvette, Latus Heiner, Apitz Christian, Schranz Dietmar
Department of Biomedical Engineering, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, Netherlands.
Department of Paediatric Cardiology and Congenital Heart Defects, German Heart Centre, Munich, Germany.
Front Physiol. 2018 Sep 10;9:1252. doi: 10.3389/fphys.2018.01252. eCollection 2018.
To quantitatively evaluate the basic pathophysiological process involved in the creation of Eisenmenger syndrome in pediatric pulmonary arterial hypertension (PAH) patients by either atrial septostomy (AS) or Potts shunt (PS) as well as to predict the effects of AS or PS in future PAH patients. The multi-scale lumped parameter CircAdapt model of the cardiovascular system was used to investigate the effects of AS and PS on cardiovascular hemodynamics and mechanics, as well as on oxygen saturation in moderate to severe PAH. The reference simulation, with cardiac output set to 2.1 l/min and mean systemic pressure to 61 mmHg, was used to create a compensated moderate PAH simulation with mPAP 50 mmHg. Thereupon we created a range of decompensated PAH simulations in which mPAP was stepwise increased from 50 to 80 mmHg. Then we simulated for each level of mPAP the acute effects of either PS or AS with connection diameters ranging between 0-16 mm. For any mPAP level, the effect on shunt flow size is much larger for the PS than for AS. Whereas right ventricular pump work in PS is mainly dependent on mPAP, in AS it depends on both mPAP and the size of the defect. The effects on total cardiac pump work were similar for PS and AS. As expected, PS resulted in a drastic decrease of lower body oxygen saturation, whereas in AS both the upper and lower body oxygen saturation decreased, though not as drastically as in PS. Our simulations support the opinion that a PS can transfer suprasystemic PAH to an Eisenmenger physiology associated with a right-to-left shunt at the arterial level. Contrary to the current opinion that PS in PAH will decompress and unload the right ventricle, we show that while a PS does lead to a decrease in mPAP toward mean systemic arterial pressure, it does not unload the right ventricle because it mainly diverts flow from the pulmonary arterial system toward the lower body systemic arteries.
定量评估小儿肺动脉高压（PAH）患者通过房间隔造口术（AS）或Potts分流术（PS）形成艾森曼格综合征所涉及的基本病理生理过程，并预测AS或PS对未来PAH患者的影响。采用心血管系统的多尺度集总参数CircAdapt模型，研究AS和PS对中重度PAH患者心血管血液动力学、力学以及氧饱和度的影响。参考模拟中，心输出量设定为2.1升/分钟，平均体循环压力设定为61毫米汞柱，用于创建平均肺动脉压（mPAP）为50毫米汞柱的代偿性中度PAH模拟。随后，我们创建了一系列失代偿性PAH模拟，其中mPAP从50毫米汞柱逐步增加到80毫米汞柱。然后，我们针对每个mPAP水平，模拟了连接直径在0至16毫米之间的PS或AS的急性效应。对于任何mPAP水平，PS对分流流量大小的影响远大于AS。PS中右心室泵功主要取决于mPAP，而在AS中则取决于mPAP和缺损大小。PS和AS对总心脏泵功的影响相似。正如预期的那样，PS导致下半身氧饱和度急剧下降，而在AS中，上半身和下半身氧饱和度均下降，尽管不如PS那样剧烈。我们的模拟支持以下观点，即PS可将系统性PAH转变为与动脉水平右向左分流相关的艾森曼格生理状态。与目前认为PAH中的PS会使右心室减压和卸载的观点相反，我们表明，虽然PS确实会导致mPAP朝着平均体循环动脉压降低，但它并不会卸载右心室，因为它主要将血流从肺动脉系统转向下半身体循环动脉。
