Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Department of Chronic Heart Failure Management, Global Center for Medical Engineering and Informatics, Osaka University, Suita, Osaka, Japan.
Am J Physiol Heart Circ Physiol. 2021 May 1;320(5):H2161-H2168. doi: 10.1152/ajpheart.00821.2020. Epub 2021 Apr 9.
Right ventricular failure (RVF) is a serious adverse event after left ventricular assist device (LVAD) implantation but difficult to be characterized. This study aimed to visualize the dynamic circulatory equilibrium of acute RVF after LVAD implantation using a new four-quadrant diagram constructed by ) cardiac function with central venous pressure (CVP) and cardiac index (CI) axes, ) arterial vascular resistance with CI and mean blood pressure (mBP) axes, ) pressure-diuretic function with mBP and net urinary sodium output (net U-Na) axes, and ) venous compliance with net U-Na and CVP axes. Twenty LVAD patients were stratified into two groups, (≤10 days) and (>10 days), according to duration of postoperative inotropic support. The preoperative equilibrium loops were small in both groups. In the early postoperative phase, the loop in became dramatically enlarged to the left and upward, indicating increased CVP and CI by LVAD support. In , however, augmentation of CI was smaller despite similarly increased CVP, and net U-Na was decreased despite increased mBP. In the late postoperative phase, the equilibrium loop in recovered as similar to that seen in . Thus, acute RVF, as shown in , was characterized by the shape of the loop constructed by marked increased CVP, a relatively small increase in CI, and concomitant impairment of pressure natriuresis. In conclusion, the novel four-quadrant presentation of systemic circulatory equilibrium provides clear visualization of RVF after LVAD implantation, thus serving as a useful guide for prompt and optimal management. Systemic circulatory dynamics are regulated by various negative feedback systems, including cardiac, arterial, venous, and renal functions, as well as autonomic nervous systems. The present novel four-quadrant presentation of their functions allows clear visualization of dynamic organ-to-organ interactions that can lead to a new circulatory equilibrium after therapeutic intervention. This new system physiological framework can serve as a useful guide for prompt and optimal management of circulatory malfunction.
右心衰竭（RVF）是左心室辅助装置（LVAD）植入后的严重不良事件，但难以确定。本研究旨在通过新构建的四象限图来可视化 LVAD 植入后急性 RVF 的动态循环平衡，该四象限图由）通过中心静脉压（CVP）和心指数（CI）轴构建的心脏功能，）通过 CI 和平均血压（mBP）轴构建的动脉血管阻力，）通过 mBP 和净尿钠排泄（net U-Na）轴构建的压力利尿功能，以及）通过 net U-Na 和 CVP 轴构建的静脉顺应性。根据术后正性肌力支持的持续时间，将 20 例 LVAD 患者分为两组， （≤10 天）和 （>10 天）。两组术前的平衡环均较小。在术后早期，组的环显著向左和向上扩大，表明 LVAD 支持增加了 CVP 和 CI。然而，在 组中，尽管 CVP 同样增加，但 CI 的增加较小，尽管 mBP 增加，但 net U-Na 减少。在术后晚期，组的平衡环恢复到与组相似的形状。因此，如 所示的急性 RVF 的特征是构建的环的形状明显增加 CVP、CI 相对较小增加以及压力利尿功能同时受损。总之，系统循环平衡的新四象限表现提供了 LVAD 植入后 RVF 的清晰可视化，因此是及时和优化管理的有用指导。系统循环动力学由各种负反馈系统调节，包括心脏、动脉、静脉和肾脏功能以及自主神经系统。这些功能的新四象限表现允许清晰地观察到治疗干预后导致新循环平衡的器官间动态相互作用。这个新的系统生理框架可以作为及时和优化管理循环功能障碍的有用指南。
