Conclusions
There are cardiovascular changes that are associated with ME/CFS, such as reduced stroke volume and resting cardiac output, decreased total blood volume, and altered heart rate variability with postural hypotension. These cardiovascular changes may contribute to the symptoms and debilitation associated with this disorder. Further research is needed to assess if and how these cardiovascular changes are associated with the severe fatigue and PEM of ME/CFS and what role deconditioning plays in symptom maintenance over time.
Abbreviations and Acronyms
HRV = heart rate variability; ME/CFS = myalgic encephalomyelitis/chronic fatigue syndrome; OI = orthostatic intolerance; PEM = postexertional malaise; POSH = postural orthostatic syndrome of hypocapnia (or hyperventilation); POTS = postural orthostatic tachycardia syndrome; VO2VT
= oxygen output at ventilatory threshold
J Am Coll Cardiol. 2021;78(10):1056-1067. © 2021 American College of Cardiology Foundation