Cardiovascular Dysfunction

Cardiovascular abnormalities are pervasive in ME/CFS and contribute substantially to disability, particularly through exercise intolerance and orthostatic symptoms. The 2024 NIH deep phenotyping study by Walitt et al. provided rigorous documentation of cardiopulmonary exercise testing abnormalities, including reduced peak oxygen consumption and chronotropic incompetence, establishing objective physiological correlates of the subjective exercise intolerance reported by patients (Walitt et al. 2024).

NoteChapter Roadmap: How to Use This Chapter

For patients: read the heart-rate and blood-pressure sections to understand orthostatic symptoms and palpitations. The post-covid section is relevant if your illness began with COVID.

For caregivers: read the summary integrated model and the heart-rate section to understand exertion intolerance and pacing needs. The vascular section can be skimmed.

For clinicians: read the cardiac, blood-pressure, and heart-rate sections for assessment of orthostatic intolerance, plus the coagulation/rheological section for microclot considerations. The sex-differences section informs female-specific presentations.

For researchers: read the post-covid, mast-cell, and summary sections. These cross-link to Chapter Integrative Models and Multi-System Pathophysiology and Chapter Immune System Dysfunction.

1 Contents

• Cardiac Function
• Vascular Dysfunction
• Blood Pressure Regulation
• Heart Rate Abnormalities
• Coagulation and Rheological Abnormalities
• Cardiovascular Dysfunction in Post-COVID ME/CFS
• Sex Differences in Cardiovascular Manifestations
• Mast Cell Activation and Cardiovascular Dysfunction
• Summary: Integrated Cardiovascular Model

References

Walitt, Brian, Komudi Singh, Samuel R LaMunion, Mark Hallett, Sandra Jacobson, Kong Chen, Yoshihisa Enose-Akahata, et al. 2024. “Deep Phenotyping of Post-Infectious Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.” Nature Communications 15 (1): 907. https://doi.org/10.1038/s41467-024-45107-3.