Mechanistic insights on age-related changes in heart-aorta-brain hemodynamic coupling using a pulse wave model of the entire circulatory system
Mechanistic insights on age-related changes in heart-aorta-brain hemodynamic coupling using a pulse wave model of the entire circulatory system
复制标题
使用整个循环系统的脉搏波模型对心脏-主动脉-脑血流动力学耦合中年龄相关变化的机制见解
DOI：
10.1152/ajpheart.00314.2023
复制
发表时间：
2023-11-15
影响因子：
4.8
通讯作者：
Pahlevan，Niema M.
中科院分区：
文献类型：
--
作者：
Aghilinejad，Arian;Amlani，Faisal;Pahlevan，Niema M.
年龄相关的主动脉生物力学变化可以通过减少血流量和增加脉冲能量传输来影响大脑。临床研究表明，心衰患者心功能受损与认知障碍有关。尽管先前的研究试图阐明年龄相关的主动脉硬化与搏动传递到大脑网络之间的复杂关系，但它们并没有充分解决主动脉硬化与左心室（LV）收缩力之间相互作用的影响（既不影响能量传递，也不影响脑灌注）。在这项研究中，我们使用了一个完善和验证的循环系统一维血流和脉搏波计算模型来解决心脏功能和脉管系统的年龄相关变化如何影响左心室-主动脉-脑血流动力学耦合的潜在机制。我们的研究结果揭示了左室收缩如何影响脉动能量传递到大脑，即使保留心输出量。我们的模型证明了存在一个最佳心率（接近正常的人类心率），它可以在不同的收缩水平下最大限度地减少向大脑传递的脉动能量。我们的研究结果进一步表明，低左室收缩力下的脑血流量减少在与年龄相关的主动脉硬化情况下更为突出。维持最佳的脑部血流量需要增加收缩力或增加心率。前者始终导致更高的脉冲功率传输，后者可以增加或减少随后的脉冲功率传输到大脑。我们研究了动脉系统和心功能的主要衰老机制对脑血流动力学的影响。我们的研究结果表明，衰老通过改变动脉硬化和左心室（LV）收缩力对心脏-主动脉-脑耦合有显著影响。了解这里涉及的潜在物理机制可能是开发更有效的治疗策略的关键一步，可以减轻lv -动脉异常偶联对神经退行性疾病和痴呆的贡献。
Age-related changes in aortic biomechanics can impact the brain by reducing blood flow and increasing pulsatile energy transmission. Clinical studies have shown that impaired cardiac function in patients with heart failure is associated with cognitive impairment. Although previous studies have attempted to elucidate the complex relationship between age-associated aortic stiffening and pulsatility transmission to the cerebral network, they have not adequately addressed the effect of interactions between aortic stiffness and left ventricle (LV) contractility (neither on energy transmission nor on brain perfusion). In this study, we use a well-established and validated one-dimensional blood flow and pulse wave computational model of the circulatory system to address how age-related changes in cardiac function and vasculature affect the underlying mechanisms involved in the LV-aorta-brain hemodynamic coupling. Our results reveal how LV contractility affects pulsatile energy transmission to the brain, even with preserved cardiac output. Our model demonstrates the existence of an optimal heart rate (near the normal human heart rate) that minimizes pulsatile energy transmission to the brain at different contractility levels. Our findings further suggest that the reduction in cerebral blood flow at low levels of LV contractility is more prominent in the setting of age-related aortic stiffening. Maintaining optimal blood flow to the brain requires either an increase in contractility or an increase in heart rate. The former consistently leads to higher pulsatile power transmission, and the latter can either increase or decrease subsequent pulsatile power transmission to the brain.NEW & NOTEWORTHYWe investigated the impact of major aging mechanisms of the arterial system and cardiac function on brain hemodynamics. Our findings suggest that aging has a significant impact on heart-aorta-brain coupling through changes in both arterial stiffening and left ventricle (LV) contractility. Understanding the underlying physical mechanisms involved here can potentially be a key step for developing more effective therapeutic strategies that can mitigate the contributions of abnormal LV-arterial coupling toward neurodegenerative diseases and dementia.