Jimeno-Almazán, Amaya, Pallarés, Jesús G, Buendía-Romero, Ángel et al. · Journal of clinical medicine · 2021 · DOI
Some people who recover from COVID-19 experience persistent fatigue and difficulty exercising for months afterward. This study tested 32 people with long-lasting COVID symptoms and found that about 12% had a specific heart problem called chronotropic incompetence—their heart rate doesn't increase normally during exercise. This heart rhythm problem may explain why some patients struggle with exercise intolerance after COVID-19.
This study identifies chronotropic incompetence as a potential cardiopulmonary mechanism underlying exercise intolerance in post-COVID syndrome. The findings are relevant to ME/CFS research because similar autonomic dysfunction and cardiac response abnormalities may contribute to post-exertional malaise and exercise intolerance in ME/CFS patients, suggesting shared physiological pathways warranting investigation.
This study does not establish chronotropic incompetence as the primary cause of post-COVID fatigue or demonstrate that this finding is specific to COVID-19 rather than other conditions. The small sample size and cross-sectional design preclude causal inference or determination of how common this abnormality truly is in the broader post-COVID population. Results cannot be generalized to hospitalized or more severely affected COVID-19 patients.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
Spotted an error in this entry? Report it →