Sze Shirley, Pan Daniel, Moss Alastair J, Ong Cheng Ken, Pareek Manish, Squire Iain B, Clark Andrew L
Department of Cardiovascular Science, National Institute for Health Research Leicester Biomedical Research Centre, University of Leicester, Leicester, United Kingdom.
Department of Respiratory Sciences, University of Leicester, Leicester, United Kingdom.
Front Cardiovasc Med. 2022 Jul 15;9:940832. doi: 10.3389/fcvm.2022.940832. eCollection 2022.
Long COVID refers to a multitude of symptoms that persist long after SARS-CoV-2 infection. Fatigue and breathlessness are the most common symptoms of long COVID across a range of studies. They are also cardinal symptoms of chronic heart failure (CHF). In this review, we propose that fatigue and breathlessness in patients with long COVID may be explained by skeletal muscle abnormalities, in a manner similar to patients with CHF. The ergoreflex is a cardiorespiratory reflex activated by exercise, which couples ventilation and cardiovascular function to exercise intensity. At least part of the symptomatology of CHF is related to abnormal skeletal muscle and an enhanced ergoreflex, resulting in heightened sympathetic, vasoconstrictor and ventilator drives. Similarly, SARS-CoV-2 infection results in a hyperinflammatory and hypercatabolic state. This leads to reduction in skeletal muscle mass and altered function. We postulate that the ergoreflex is chronically overstimulated, resulting in fatigue and breathlessness. Exercise training preserves muscle mass and function as well as reduces ergoreflex activation; therefore may have a role in improving symptoms associated with long COVID. Should the ergoreflex be proven to be an important pathophysiological mechanism of long COVID, tailored exercise interventions should be trialed with the aim of improving both symptoms and perhaps outcomes in patients with long COVID.
“长新冠”指的是在感染严重急性呼吸综合征冠状病毒2（SARS-CoV-2）后很长时间仍持续存在的多种症状。在一系列研究中，疲劳和呼吸急促是“长新冠”最常见的症状。它们也是慢性心力衰竭（CHF）的主要症状。在本综述中，我们提出，“长新冠”患者的疲劳和呼吸急促可能与骨骼肌异常有关，其方式类似于CHF患者。运动反射是一种由运动激活的心肺反射，它将通气和心血管功能与运动强度联系起来。CHF的至少部分症状学与骨骼肌异常和增强的运动反射有关，导致交感神经、血管收缩和通气驱动增强。同样，SARS-CoV-2感染会导致高炎症和高分解代谢状态。这会导致骨骼肌质量减少和功能改变。我们推测运动反射会被长期过度刺激，从而导致疲劳和呼吸急促。运动训练可以保留肌肉质量和功能，并减少运动反射激活；因此可能在改善与“长新冠”相关的症状方面发挥作用。如果运动反射被证明是“长新冠”的一个重要病理生理机制，应该尝试进行有针对性的运动干预，以改善“长新冠”患者的症状，或许还能改善其预后。
