Hemodynamic exercise responses with a continuous-flow left ventricular assist device: Comparison of patients' response and cardiorespiratory simulations
Hemodynamic exercise responses with a continuous-flow left ventricular assist device: Comparison of patients' response and cardiorespiratory simulations
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DOI：
10.1371/journal.pone.0229688
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发表时间：
2020-03-18
期刊：
影响因子：
3.7
通讯作者：
Moscato, Francesco
中科院分区：
文献类型：
--
作者：
Gross, Christoph;Fresiello, Libera;Moscato, Francesco
背景左心室辅助装置（LVAD）是治疗终末期心力衰竭患者的一种成熟的治疗方法。由于LVAD目前对运动需求没有反应，因此还将注意力集中在运动能力和由此产生的生活质量的改善上。本研究的目的是探讨血流动力学反应最大运动试验期间观察到的推断潜在的患者状态，因此调查可能的诊断从LVAD派生的数据和推进发展的生理适应LVAD controllers.MethodsHigh分辨率连续LVAD流量波形记录从14 LVAD患者和评估在休息和最大自行车运动试验（n = 24）。根据最小值（Q（MIN））、平均值（Q（MEAN））、最大流量（Q（MAX））和流量脉动性（Q（P2P））的增加（向上箭头）或减少（向下箭头）分析对运动的反应。为了解释临床数据，使用心肺数值模拟器再现患者在休息和运动时的血流动力学。不同的心血管情况下，包括变时性和变力性反应，外周血管舒张，和主动脉瓣病变进行了系统的模拟和比较患者的respons.ResultsDifferent患者的反应运动观察。最常见的反应是从休息到运动的Delta Q（MIN）向上箭头和Delta Q（P2P）向上箭头的阳性变化（70%的运动试验）。迄今为止从未在患者中报告的两种反应通过Q（MIN）向上箭头和Q（P2P）向下箭头（在17%中观察到）以及Q（MIN）向下箭头和Q（P2P）向上箭头（在13%中观察到）区分。模拟表明，Q（P2P）向下箭头可以导致左心室收缩力降低，Q（MIN）向上箭头可以发生更好的左心室收缩力和/或主动脉瓣关闭不全。不同的波形响应运动，包括以前未观察到的，被报道。模拟表明左心室收缩力是不同反应的主要决定因素，因此改善了患者分层，以确定患者组如何从运动反应LVAD控制中获益。
BackgroundLeft ventricular assist devices (LVADs) are an established treatment for end stage heart failure patients. As LVADs do not currently respond to exercise demands, attention is also directed towards improvements in exercise capacity and resulting quality of life. The aim of this study was to explore hemodynamic responses observed during maximal exercise tests to infer underlying patient status and therefore investigate possible diagnostics from LVAD derived data and advance the development of physiologically adaptive LVAD controllers.MethodsHigh resolution continuous LVAD flow waveforms were recorded from 14 LVAD patients and evaluated at rest and during maximum bicycle exercise tests (n = 24). Responses to exercise were analyzed in terms of an increase (up arrow) or decrease (down arrow) in minimum (Q(MIN)), mean (Q(MEAN)), maximum flow (Q(MAX)) and flow pulsatility (Q(P2P)). To interpret clinical data, a cardiorespiratory numerical simulator was used that reproduced patients' hemodynamics at rest and exercise. Different cardiovascular scenarios including chronotropic and inotropic responses, peripheral vasodilation, and aortic valve pathologies were simulated systematically and compared to the patients' responses.ResultsDifferent patients' responses to exercise were observed. The most common response was a positive change of Delta Q(MIN)up arrow and Delta Q(P2P)up arrow from rest to exercise (70% of exercise tests). Two responses, which were never reported in patients so far, were distinguished by Q(MIN)up arrow and Q(P2P)down arrow (observed in 17%) and by Q(MIN)down arrow and Q(P2P)up arrow (observed in 13%). The simulations indicated that the Q(P2P)down arrow can result from a reduced left ventricular contractility and that the Q(MIN)up arrow can occur with a better left ventricular contractility and/or aortic insufficiency.ConclusionLVAD flow waveforms determine a patients' hemodynamic "fingerprint" from rest to exercise. Different waveform responses to exercise, including previously unobserved ones, were reported. The simulations indicated the left ventricular contractility as a major determinant for the different responses, thus improving patient stratification to identify how patient groups would benefit from exercise-responsive LVAD control.