Voitl Peter, Vollkron Michael, Bergmeister Helga, Wieselthaler Georg, Schima Heinrich
Center for Biomedical Engineering and Physics, Medical University of Vienna, Vienna, Austria.
Artif Organs. 2009 Jan;33(1):77-80. doi: 10.1111/j.1525-1594.2008.00677.x.
Mechanical support offered by rotary pumps is increasingly used to assist the failing heart, although several questions concerning physiology remain. In this study, we sought to evaluate the effect of left-ventricular assist device (VAD) therapy on coronary hemodynamics, myocardial oxygen consumption, and pulmonary blood flow in sheep. We performed an acute experiment in 10 sheep to obtain invasively measured coronary perfusion data, as well as pressure and flow conditions under cardiovascular assistance. A DeBakey VAD (MicroMed Cardiovascular, Inc., Houston, TX, USA) was implanted, and systemic and coronary hemodynamic measurements were performed at defined baseline conditions and at five levels of assistance. Data were measured when the pump was clamped, as well as under minimum, maximum, and moderate levels of assistance, and in a pump-off condition where backflow occurs. Coronary flow at the different levels of support showed no significant impact of pump activity. The change from baseline ranged from -10.8% to +4.6% (not significant [n.s.]). In the pulmonary artery, we observed a consistent increase in flow up to +4.5% (n.s.) and a decrease in the pulmonary artery pressure down to -14.4% (P = 0.004). Myocardial oxygen consumption fell with increasing pump support down to -34.6% (P = 0.008). Left-ventricular pressure fell about 52.2% (P = 0.016) as support was increased. These results show that blood flow in the coronary arteries is not affected by flow changes imposed by rotary blood pumps. An undiminished coronary perfusion at falling oxygen consumption might contribute to cardiac recovery.
尽管关于生理学仍存在一些问题，但旋转泵提供的机械支持越来越多地用于辅助衰竭心脏。在本研究中，我们试图评估左心室辅助装置（VAD）治疗对绵羊冠状动脉血流动力学、心肌氧耗和肺血流量的影响。我们对10只绵羊进行了一项急性实验，以获得有创测量的冠状动脉灌注数据，以及心血管辅助下的压力和血流状况。植入了一台德巴基VAD（美国德克萨斯州休斯顿市MicroMed心血管公司），并在确定的基线条件和五个辅助水平下进行了全身和冠状动脉血流动力学测量。在泵夹闭时、最低、最高和中等辅助水平下以及在出现回流的泵关闭状态下测量数据。不同支持水平下的冠状动脉血流显示泵活动没有显著影响。与基线相比的变化范围为-10.8%至+4.6%（无显著性差异[n.s.]）。在肺动脉中，我们观察到血流量持续增加高达+4.5%（无显著性差异），肺动脉压力下降至-14.4%（P = 0.004）。随着泵支持增加，心肌氧耗下降至-34.6%（P = 0.008）。随着支持增加，左心室压力下降约52.2%（P = 0.016）。这些结果表明，冠状动脉血流不受旋转血泵引起的血流变化影响。在氧耗下降时冠状动脉灌注未减少可能有助于心脏恢复。
