Rotary pump speed modulation for generating pulsatile flow and phasic Left ventricular volume unloading in a bovine model of chronic ischemic heart failure
Rotary pump speed modulation for generating pulsatile flow and phasic Left ventricular volume unloading in a bovine model of chronic ischemic heart failure
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DOI：
10.1016/j.healun.2014.09.017
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发表时间：
2015-01-01
影响因子：
8.9
通讯作者：
Koenig, Steven C.
中科院分区：
文献类型：
--
作者：
Soucy, Kevin G.;Giridharan, Guruprasad A.;Koenig, Steven C.
背景：旋转血泵以恒定转速（rpm）运行，降低血管搏动性和心室收缩末和舒张末容积的变化，这可能导致不良事件，包括主动脉功能不全和胃肠道出血。在这项研究中，使用临床植入的离心左心室辅助装置（LVAD），在缺血性心力衰竭（IHF）牛模型（n = 10）中研究了泵速调节算法，以产生脉动性和心室收缩末和舒张末容积变化。方法：在基线、恒定泵速、异步（19-60周期/分钟）和同步（脉冲和反脉冲）泵速调制（低相对脉冲速度（25%）为3,200 - 800转/分，高相对脉冲速度（38%）为2,900 - 1,100转/分）期间记录血液动力学和血液学测量。测量终末器官灌注、血流动力学和泵参数，以表征每种速度调制剖面的脉动性、心肌负荷和LVAD性能。结果：与匀速手术相比，速度调节可使主动脉脉压升高、血流动力学能量过剩和终末器官灌注增加（p < 0.01）。与IHE基线相比，左心室外功和心肌耗氧量显著降低（p < 0.01），但代价是LVAD功率消耗增加。结论：泵速调节可增加脉搏度，改善心功能和终末器官灌注，但异步模式具有无传感器控制的技术优势。对长期支持期间异步泵速调节的研究是有必要的，以验证这样的假设，即在恒定泵速下操作LVAD可以最大限度地减少由LVAD支持的患者的不良事件。(C) 2015国际心肺移植学会。版权所有。
BACKGROUND: Rotary blood pumps operate at a constant speed (rpm) that diminishes vascular pulsatility and variation in ventricular end-systolicand end-diastolic volumes, which may contribute to adverse events, including aortic insufficiency and gastrointestinal bleeding. In this study, pump speed modulation algorithms for generating pulsatility and variation in ventricular end-systolic and end-diastolic volumes were investigated in an ischemic heart failure (IHF) bovine model (n = 10) using a clinically implanted centrifugal-flow left ventricular assist device (LVAD).METHODS: Hemodynamic and hematologic measurements were recorded during THE baseline, constant pumps speeds, and asynchronous (19-60 cycles/min) and synchronous (copulse and counterpulse) pump speed modulation profiles using low relative pulse speed (25%) of 3,200 800 rpm and high relative pulse speed (38%) of 2,900 1,100 rpm. End-organ perfusion, hemodynamics, and pump parameters were measured to characterize pulsatility, myocardial workload, and LVAD performance for each speed modulation profile.RESULTS: Speed modulation profiles augmented aortic pulse pressure, surplus hemodynamic energy, and end-organ perfusion (p < 0.01) compared with operation at constant speed. Left ventricular external work and myocardial oxygen consumption were significantly reduced compared with IHE baseline (p < 0.01) but at the expense of higher LVAD power consumption.CONCLUSIONS: Pump speed modulation increases pulsatility and improves cardiac function and end-organ perfusion, but the asynchronous mode provides the technologic advantage of sensorless control. Investigation of asynchronous pump speed modulation during long-term support is warranted to test the hypothesis that operating an LVAD with speed modulation will minimize adverse events in patients supported by an LVAD that may be associated with long-term operation at a constant pump speed. (C) 2015 International Society for Heart and Lung Transplantation. All rights reserved.