Intraventricular thrombus formation in the LVAD-assisted heart studied in a mock circulatory loop
Intraventricular thrombus formation in the LVAD-assisted heart studied in a mock circulatory loop
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DOI：
10.1007/s11012-016-0433-z
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发表时间：
2017-02-01
期刊：
影响因子：
2.7
通讯作者：
May-Newman, Karen
中科院分区：
文献类型：
--
作者：
Reider, Claudine;Moon, Juyeun;May-Newman, Karen
左心室辅助装置(LVAD)是一种机械泵，通过手术连接到左心室和主动脉。临床研究表明，LVADs改善了患者的健康和生活质量，并显著降低了心力衰竭的死亡率。在高LVAD支持期间，血流完全通过LVAD，主动脉瓣持续关闭，心脏与泵串联运行。因此，室内血流的正常流体动力学改变，并与血栓的发展有关，在自然心脏和左心室。我们在这项研究中的目标是模拟一名血栓复发的患者，并量化随着血栓的发展左室内流场的变化。在一定的LVAD支撑条件下，对透明硅胶模型进行了粒子图像测速。结果表明，在LVOT中出现小血栓为进一步生长创造了有利条件，特别是在存在高LVAD支持的情况下。随着血栓的增大，它开始影响正常的涡流模式，进一步降低左心室流出道的流速和脉动性。对患者和LVAD支持的实验模型的涡旋动力学和停滞区的评估产生了可用于评估LVAD患者血栓风险和降低这种风险的策略的定量指标。
Left ventricular assist devices (LVADs) are mechanical pumps that are surgically attached to the left ventricle and aorta. Clinical studies show that LVADs improve patient health and quality of life, and dramatically reduce the mortality of cardiac failure. During periods of high LVAD support, blood flow occurs entirely through the LVAD, the aortic valve is continuously closed, and the heart operates in series with the pump. Thus the normal fluid dynamics of intraventricular flow are altered and linked to the development of thrombus in both the native heart and LVAD. Our goal in this study was to simulate a patient with a recurring thrombus and quantify the variations in the flow field in the LV as the thrombus developed. Particle image velocimetry measurements of transparent silicone models were performed for a range of LVAD support conditions. Results show that the presence of a small thrombus in the LVOT creates a favorable condition for further growth, especially in the presence of high LVAD support. As the thrombus enlarges, it begins to affect the normal vortex-flow pattern, further reducing flow rate and pulsatility in the LVOT. Evaluation of vortex dynamics and stasis regions in both patients and experimental models of LVAD support yield quantitative metrics that can be used to assess the risk of thrombus and the development of strategies to reduce this risk in LVAD patients.