Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
Sci Transl Med. 2018 Feb 28;10(430). doi: 10.1126/scitranslmed.aao2980.
The full potential of mechanical circulatory systems in the treatment of cardiogenic shock is impeded by the lack of accurate measures of cardiac function to guide clinicians in determining when to initiate and how to optimally titrate support. The left ventricular end diastolic pressure (LVEDP) is an established metric of cardiac function that refers to the pressure in the left ventricle at the end of ventricular filling and immediately before ventricular contraction. In clinical practice, LVEDP is typically only inferred from, and poorly correlates with, the pulmonary capillary wedge pressure (PCWP). We leveraged the position of an indwelling percutaneous ventricular assist device and advanced data analysis methods to obtain LVEDP from the hysteretic operating metrics of the device. We validated our hysteresis-derived LVEDP measurement using mock flow loops, an animal model of cardiac dysfunction, and data from a patient in cardiogenic shock to show greater measurement precision and correlation with actual pressures than traditional inferences via PCWP. Delineation of the nonlinear relationship between device and heart adds insight into the interaction between ventricular support devices and the native heart, paving the way for continuous assessment of underlying cardiac state, metrics of cardiac function, potential closed-loop automated control, and rational design of future innovations in mechanical circulatory support systems.
机械循环系统在治疗心源性休克方面的全部潜力受到阻碍,因为缺乏准确的心脏功能测量方法来指导临床医生确定何时开始以及如何最佳地调整支持力度。左心室舒张末期压(LVEDP)是一种已确立的心脏功能指标,指的是心室充盈结束时和心室收缩前即刻左心室中的压力。在临床实践中,LVEDP 通常仅通过推断得出,并且与肺毛细血管楔压(PCWP)相关性较差。我们利用留置经皮心室辅助装置的位置和先进的数据分析方法,从设备的滞后操作指标中获取 LVEDP。我们使用模拟流量回路、心脏功能障碍的动物模型以及心源性休克患者的数据验证了我们的滞后衍生 LVEDP 测量方法,结果表明,与通过 PCWP 进行传统推断相比,该方法具有更高的测量精度和与实际压力的相关性。设备和心脏之间的非线性关系的描绘增加了对心室辅助装置和原生心脏之间相互作用的深入了解,为连续评估潜在的心脏状态、心脏功能指标、潜在的闭环自动控制以及机械循环支持系统的未来创新的合理设计铺平了道路。