Background

A large number of patients around the world are recovering from coronavirus disease 2019 (COVID-19); many of them report persistence of symptoms. The aim of this study was to test pulmonary, cardiovascular, and peripheral responses to exercise in patients recovering from COVID-19.

Methods

Patients who recovered from COVID-19 were prospectively evaluated using a combined anatomic and functional assessment. All patients underwent clinical examination, laboratory tests, and combined stress echocardiography and cardiopulmonary exercise testing. Left ventricular volumes, ejection fraction, stroke volume, heart rate, E/e′ ratio, right ventricular function, oxygen consumption (Vo₂), lung volumes, ventilatory efficiency, oxygen saturation, and muscle oxygen extraction were measured in all effort stages and compared with values in historical control subjects.

Results

A total of 71 patients were assessed 90.6 ± 26 days after the onset of COVID-19 symptoms. Only 23 (33%) were asymptomatic. The most common symptoms were fatigue (34%), muscle weakness or pain (27%), and dyspnea (22%). Vo₂ was lower among post-COVID-19 patients compared with control subjects (P = .03, group-by-time interaction P = .007). Reduction in peak Vo₂ was due to a combination of chronotropic incompetence (75% of post-COVID-19 patients vs 8% of control subjects, P < .0001) and an insufficient increase in stroke volume during exercise (P = .0007, group-by-time interaction P = .03). Stroke volume limitation was mostly explained by diminished increase in left ventricular end-diastolic volume (P = .10, group-by-time interaction P = .03) and insufficient increase in ejection fraction (P = .01, group-by-time interaction P = .01). Post-COVID-19 patients had higher peripheral oxygen extraction (P = .004) and did not have significantly different respiratory and gas exchange parameters compared with control subjects.

Conclusions

Patients recovering from COVID-19 have symptoms associated with objective reduction in peak Vo₂. The mechanism of this reduction is complex and mainly involves a combination of attenuated heart rate and stroke volume reserve.

中文翻译：

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2019 年冠状病毒病康复患者的心肺功能异常

背景

世界各地有大量患者正在从 2019 年冠状病毒病 (COVID-19) 中康复；他们中的许多人报告症状持续存在。本研究的目的是测试从 COVID-19 中恢复的患者对运动的肺、心血管和外周反应。

方法

使用结合解剖学和功能评估的前瞻性评估从 COVID-19 中康复的患者。所有患者均接受临床检查、实验室检查以及联合负荷超声心动图和心肺运动试验。在所有努力阶段测量左心室容积、射血分数、每搏输出量、心率、E/e'比、右心室功能、耗氧量 (V o ₂ )、肺容积、通气效率、氧饱和度和肌肉氧提取并与历史对照受试者的值进行比较。

结果

在 COVID-19 症状出现后 90.6 ± 26 天，对总共 71 名患者进行了评估。只有 23 人（33%）没有症状。最常见的症状是疲劳 (34%)、肌肉无力或疼痛 (27%) 和呼吸困难 (22%)。与对照组相比，COVID-19 后患者的V o ₂较低（P  = .03，分组时间交互P  = .007）。V o ₂峰值的降低是由于变时功能不全（75% 的 COVID-19 后患者 vs 8% 的对照组，P  < .0001）和运动期间每搏输出量增加不足（P  = .0007 , 分组时间交互P = .03）。每搏输出量受限的主要原因是左心室舒张末期容积增加减少（P  = .10，按时间分组的交互作用P  = .03）和射血分数增加不足（P  = .01，按时间分组）交互作用P  = .01）。 与对照组相比，COVID-19 后患者的外周氧提取率更高 ( P = .004)，并且呼吸和气体交换参数没有显着差异。

结论

从 COVID-19 中恢复的患者出现与峰值 V o ₂客观降低相关的症状。这种降低的机制很复杂，主要涉及心率减慢和每搏输出量储备的组合。