Love Holley C, Timms Daniel L, McMahon Richard A
Annu Int Conf IEEE Eng Med Biol Soc. 2015;2015:274-7. doi: 10.1109/EMBC.2015.7318353.
Cardiac recovery has been observed in end-stage heart failure patients with mechanical circulatory support. An intra-aortic ventricular assist device (IntraVAD) is a novel rotary blood pump designed to operate in the ascending aorta behind the aortic valve, working in series with the compromised left ventricle (LV). Such a device requires optimal motion control in order to enhance the myocardial perfusion and thus promote cardiac recovery. Therefore, a reverse-rotating control (RRc) mode has been proposed to increase the mean arterial pressure (MAP) in diastole where the most coronary flow occurs. The RRc mode consists of two motions - forward rotating speed (FS) and reversely rotating speed (RS). The capability of cardiac recovery of three control modes, including continuous', on/off ' and RRc' modes, was evaluated in vitro. Stroke work (SW), ventricular volume, coronary perfusion pressure (CPP), and arterial pulsatility index (API) were used to evaluate LV unloading, myocardial perfusion and arterial pulsatility. The results show that, all three modes increased the LV stroke work (0.98W vs 1.00W vs 1.01W for continuous, on/off and RRc, respectively; baseline 0.9W) and decreased both end-diastolic volume (EDV) and end-systolic volume (ESV). The "RRc" mode improved CPP significantly (78.4 mm Hg compared to 66.4 mmHg and 70.9 mm Hg for continuous and on/off modes; baseline 71 mm Hg). The arterial pulsatility was higher in RRc' mode (0.84 compared to 0.43 and 0.59; baseline 0.48). In summary, the IntraVAD operating in the RRc mode can successfully unload the LV, enhance the myocardial perfusion, and restore the arterial pulsatility; therefore, it could be a promising therapeutic option to bridge heart failure patients to recovery.
在接受机械循环支持的终末期心力衰竭患者中已观察到心脏功能的恢复。主动脉内心室辅助装置（IntraVAD）是一种新型旋转血泵，设计用于在主动脉瓣后方的升主动脉中运行，与受损的左心室（LV）串联工作。这种装置需要优化的运动控制，以增强心肌灌注，从而促进心脏功能恢复。因此，有人提出了一种反向旋转控制（RRc）模式，以增加舒张期的平均动脉压（MAP），此时冠状动脉血流最为丰富。RRc模式由两种运动组成——正向转速（FS）和反向转速（RS）。在体外评估了三种控制模式（包括“连续”、“开/关”和“RRc”模式）促进心脏功能恢复的能力。使用每搏功（SW）、心室容积、冠状动脉灌注压（CPP）和动脉搏动指数（API）来评估左心室负荷减轻、心肌灌注和动脉搏动情况。结果表明，所有三种模式均增加了左心室每搏功（连续、开/关和RRc模式分别为0.98W、1.00W和1.01W；基线为0.9W），并减少了舒张末期容积（EDV）和收缩末期容积（ESV）。“RRc”模式显著提高了CPP（连续模式和开/关模式分别为66.4 mmHg和70.9 mmHg，而RRc模式为78.4 mmHg；基线为71 mmHg）。“RRc”模式下的动脉搏动更高（分别为0.84，而连续模式和开/关模式为0.43和0.59；基线为0.48）。总之，以RRc模式运行的IntraVAD可以成功减轻左心室负荷，增强心肌灌注，并恢复动脉搏动；因此，它可能是帮助心力衰竭患者恢复的一种有前景的治疗选择。
