Fu Yan, Qiao Aike, Yang Yao, Fan Xiangming
College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China.
Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
Front Physiol. 2020 Mar 17;11:207. doi: 10.3389/fphys.2020.00207. eCollection 2020.
The one and a half ventricle repair (1.5VR) is a common clinical choice for patients with right heart dysfunction. Considering the influence of blood circulation failure and reoperation in urgent need, this essay aims to explore the hemodynamic effects of different pulmonary vascular resistance (PVR) values on reoperation after 1.5VR failure.
The lumped parameter model (LPM) was used to simulate the reoperation, including the return biventricular repair (2VR), ligation of azygos vein (1.5VR') and return single ventricular repair (1.0VR). Firstly, the debugging parameters were used to simulate the hemodynamics of 2VR. Secondly, the value of PVR was changed from one to four times while the other parameters remained unchanged. Finally, 15 cardiac cycles were simulated and the 15th result was obtained. In this work, the left and right ventricular stroke work and their sum (Plv, Prv, Ptotal), the left and right ventricular ejection fraction (LVEF, RVEF), the mean Cardiac Output (mCO) and the mean pressure and flow-rate ratio of superior and inferior vena cava (mPsvc\mPivc and mQsvc\mQivc), respectively, were used to describe the hemodynamics of reoperation.
With the change of PVR from one to four times, the values of Plv, Prv, Ptotal, LVEF, and RVEF gradually decreased. The change rate of Plv, Ptotal and LVEF of 1.0VR were the largest in the three kinds of reoperation. The change rate of Prv of 1.5VR' was larger than that of 2VR, but it was the opposite for their EF change rate. The mCO of 2VR, 1.5VR', and 1.0VR decreased by 18.53%, 37.58%, and 48.07%, respectively. The mPsvc\mPivc of 1.5VR' increased from 3.76 to 6.77 and the mQsvc\mQivc decreased from 0.55 to 0.36, while the mPsvc\mPivc and mQsvc\mQivc of 2VR and 1.0VR remained 1 and 0.67, respectively. The peak value of the tricuspid flow-rate (Qti) waveform of 2VR and 1.5VR' changed from "E peak" to "A peak."
The numerical results demonstrate the highly reoperation-dependent hemodynamic consequences and their responses to variations in PVR. Comprehensive analysis of EF, mCO and ventricular stroke work indicates that PVR has a greater impact on 1.5VR' and 1.0VR. Therefore, we suggest that the selection strategy of reoperation should focus on PVR.
对于右心功能不全患者，单心室合并半心室修复术（1.5VR）是一种常见的临床选择。考虑到血液循环衰竭和急需再次手术的影响，本文旨在探讨不同肺血管阻力（PVR）值对1.5VR失败后再次手术的血流动力学影响。
采用集总参数模型（LPM）模拟再次手术，包括恢复双心室修复术（2VR）、奇静脉结扎术（1.5VR'）和恢复单心室修复术（1.0VR）。首先，使用调试参数模拟2VR的血流动力学。其次，在其他参数不变的情况下，将PVR值从1倍改变到4倍。最后，模拟15个心动周期并获得第15个结果。在本研究中，分别使用左、右心室每搏功及其总和（Plv、Prv、Ptotal）、左、右心室射血分数（LVEF、RVEF）、平均心输出量（mCO）以及上、下腔静脉的平均压力和流量比（mPsvc\mPivc和mQsvc\mQivc）来描述再次手术的血流动力学。
随着PVR从1倍增加到4倍，Plv、Prv、Ptotal、LVEF和RVEF的值逐渐降低。在三种再次手术中，1.0VR的Plv、Ptotal和LVEF的变化率最大。1.5VR'的Prv变化率大于2VR，但其EF变化率则相反。2VR、1.5VR'和1.0VR的mCO分别下降了18.53%、37.58%和48.07%。1.5VR'的mPsvc\mPivc从3.76增加到6.77，mQsvc\mQivc从0.55下降到0.36，而2VR和1.0VR的mPsvc\mPivc和mQsvc\mQivc分别保持在1和0.67。2VR和1.5VR'的三尖瓣流速（Qti）波形峰值从“E峰”变为“A峰”。
数值结果表明再次手术对血流动力学后果有高度依赖性，且其对PVR变化有响应。对EF、mCO和心室每搏功的综合分析表明，PVR对1.5VR'和1.0VR的影响更大。因此，我们建议再次手术的选择策略应关注PVR。
