Davenport, Todd E, Lehnen, Mary, Stevens, Staci R et al. · Frontiers in pediatrics · 2019 · DOI
This review examines how people with ME/CFS respond to exercise differently than healthy people. Researchers found that during exercise tests, people with ME/CFS have a blunted heart rate response—their heart rate doesn't increase as much as expected for the amount of work they're doing. This abnormal response, called chronotropic intolerance, may help explain why exercise worsens symptoms in ME/CFS patients.
Understanding chronotropic intolerance could provide objective evidence for ME/CFS and help explain the mechanism behind post-exertional malaise, which is the defining feature of the disease. This knowledge could guide clinicians in advising patients about activity management and may inform development of targeted treatments based on underlying cardiovascular dysfunction.
This review does not establish causation or prove that chronotropic intolerance is the sole cause of post-exertional malaise. It does not clarify whether CI is a primary disease mechanism or a secondary consequence of ME/CFS, nor does it demonstrate that treating CI would eliminate PEM symptoms. Additionally, the findings are based on aggregated literature rather than new experimental data.
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 →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Davenport, Todd E, Lehnen, Mary, Stevens, Staci R, VanNess, J Mark, Stevens, Jared, & Snell, Christopher R (2019). Chronotropic Intolerance: An Overlooked Determinant of Symptoms and Activity Limitation in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome?. Frontiers in pediatrics. https://doi.org/10.3389/fped.2019.00082
BibTeX
@article{mecfsatlas-davenport-2019-chronotropic-intolerance,
author = {Davenport, Todd E and Lehnen, Mary and Stevens, Staci R and VanNess, J Mark and Stevens, Jared and Snell, Christopher R},
title = {Chronotropic Intolerance: An Overlooked Determinant of Symptoms and Activity Limitation in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome?},
journal = {Frontiers in pediatrics},
year = {2019},
doi = {10.3389/fped.2019.00082},
note = {PubMed: 30968005},
url = {https://www.mecfsatlas.com/evidence/davenport-2019-chronotropic-intolerance},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-29. https://www.mecfsatlas.com/evidence/davenport-2019-chronotropic-intolerance
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