Stewart, J, Weldon, A, Arlievsky, N et al. · Clinical autonomic research : official journal of the Clinical Autonomic Research Society · 1998 · DOI
This study looked at how the nervous system controls heart rate in children with ME/CFS during a tilt test (where patients lie flat then are gradually tilted upright). Researchers found that children with ME/CFS had much lower heart rate variability—a measure of how well the nervous system adjusts the heart—compared to children who faint from other causes and healthy controls. When tilted, children with ME/CFS did not show the normal nervous system adjustments that other groups showed, suggesting their autonomic nervous system (which controls involuntary functions) may not be working properly.
This study provides mechanistic evidence that ME/CFS involves fundamental autonomic nervous system dysfunction distinct from other causes of fainting, not merely orthostatic intolerance. Understanding that autonomic dysregulation occurs even at baseline—and worsens under physiologic stress—may help explain multiple ME/CFS symptoms and guide development of targeted autonomic therapies.
This study does not prove that autonomic dysfunction is the primary cause of ME/CFS or that it accounts for all symptoms in the disease. The cross-sectional design cannot establish whether autonomic impairment precedes CFS onset or develops as a consequence of the illness. The study examined only pediatric patients during a single physiologic challenge and may not generalize to adult ME/CFS populations or other stress conditions.
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
Stewart, J, Weldon, A, Arlievsky, N, Li, K, & Munoz, J (1998). Neurally mediated hypotension and autonomic dysfunction measured by heart rate variability during head-up tilt testing in children with chronic fatigue syndrome.. Clinical autonomic research : official journal of the Clinical Autonomic Research Society. https://doi.org/10.1007/BF02267785
BibTeX
@article{mecfsatlas-stewart-1998-neurally-mediated,
author = {Stewart, J and Weldon, A and Arlievsky, N and Li, K and Munoz, J},
title = {Neurally mediated hypotension and autonomic dysfunction measured by heart rate variability during head-up tilt testing in children with chronic fatigue syndrome.},
journal = {Clinical autonomic research : official journal of the Clinical Autonomic Research Society},
year = {1998},
doi = {10.1007/BF02267785},
note = {PubMed: 9791743},
url = {https://www.mecfsatlas.com/evidence/stewart-1998-neurally-mediated},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-27. https://www.mecfsatlas.com/evidence/stewart-1998-neurally-mediated
Contribute
Private, reviewed by a human. Not a public comment thread.