Division of Thoracic and Cardiovascular Surgery, University of Louisville, Louisville, KY 40202, USA.
J Heart Lung Transplant. 2013 Jun;32(6):581-7. doi: 10.1016/j.healun.2013.02.010. Epub 2013 Mar 27.
Continuous-flow ventricular assist devices (CVADs) have gained widespread use as an effective clinical therapy for patients with advanced-stage heart failure. Axial and centrifugal CVADs have been successfully used as bridge-to-transplant and destination therapy. CVADs are smaller, more reliable, and less complex than the first-generation pulsatile-flow ventricular assist devices. Despite their recent clinical success, arteriovenous malformations, gastrointestinal bleeding, hemorrhagic strokes, aortic valve insufficiency, and valve fusion have been reported in heart failure patients supported by CVADs. It has been hypothesized that diminished arterial pressure and flow pulsatility delivered by CVAD may be a contributing factor to these adverse events. Subsequently, the clinical significance of vascular pulsatility continues to be highly debated. Studies comparing pulsatile-flow and continuous-flow support have presented conflicting findings, largely due to variations in device operation, support duration, and the criteria used to quantify pulsatility. Traditional measurements of pulse pressure and pulsatility index are less effective at quantifying pulsatility for mechanically derived flows, particularly with the growing trend of CVAD speed modulation to achieve various pulsatile flow patterns. Kinetic measurements of energy equivalent pressure and surplus hemodynamic energy can better quantify pulsatile energies, yet technologic and conceptual challenges are impeding their clinical adaption. A review of methods for quantifying vascular pulsatility and their application as a research tool for investigating physiologic responses to CVAD support are presented.
连续血流心室辅助装置（CVAD）已广泛应用于晚期心力衰竭患者的有效临床治疗。轴流式和离心式 CVAD 已成功用作桥接移植和终末期治疗。CVAD 比第一代搏动血流心室辅助装置更小、更可靠且更简单。尽管它们最近在临床上取得了成功，但 CVAD 支持的心力衰竭患者报告了动静脉畸形、胃肠道出血、出血性中风、主动脉瓣关闭不全和瓣膜融合等不良事件。据推测，CVAD 输送的动脉血压和血流搏动性降低可能是这些不良事件的一个促成因素。随后，血管搏动性的临床意义仍在激烈争论中。比较搏动血流和连续血流支持的研究结果存在冲突，主要原因是装置操作、支持持续时间和用于量化搏动性的标准存在差异。传统的脉搏压和搏动指数测量方法在量化机械衍生流的搏动性方面效果较差，尤其是随着 CVAD 速度调节以实现各种搏动流模式的趋势不断增加。能量等效压力和剩余血流动力学能量的动力学测量可以更好地量化搏动性能量，但技术和概念上的挑战阻碍了它们在临床上的应用。本文回顾了量化血管搏动性的方法及其作为研究工具在研究 CVAD 支持对生理反应的应用。
