Chronic fatigue syndrome: comments on deconditioning, blood volume and resulting cardiac function

Abstract

Cardiovascular and autonomic dysfunction have been suggested to underlie the symptoms accompanying CFS (chronic fatigue syndrome). In the present issue of Clinical Science, Hurwitz and co-workers have investigated whether deficits were present in cardiac output and blood volume in a cohort of patients with CFS and if these were linked to illness severity and sedentary lifestyle. The results clearly demonstrate reduced cardiac stroke volume and cardiac output in more severely afflicted patients with CFS, which is primarily attributable to a measurable reduction in blood volume. Similar findings are observed in microgravity and bed rest deconditioning, in forms of orthostatic intolerance and, to a lesser extent, in sedentary people. The circulatory consequences of reduced cardiac output may help to account for many of the findings of the syndrome.

Treatment Avenues in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Split-gender Pharmacogenomic Study of Gene-expression Modules

“…14 Therefore, these conditions may be related to reduced cardiac stroke volume and cardiac output seen in ME/CFS. 61 While the identification of these gene modules is consistent with our previous work, and with the general literature on ME/CFS, it is important to understand how these pathways may give rise to ME/CFS symptomatology. Regression of female gene-expression values onto fatigue measures showed several significant associations between the identified affected gene modules and ME/CFS symptoms.…”

Orthostatic Challenge Causes Distinctive Symptomatic, Hemodynamic and Cognitive Responses in Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

“…An alternative explanation for our findings is that the endothelial dysfunction that is well documented in COVID-19 (47) may lead to increased arteriolar tone-an imbalance between vasodilating and vasoconstricting mediators. We speculate that this may become manifest during standing because standing exaggerates the lower blood volume and lower extremity venous pooling that has been documented in ME/CFS (48,49) and in Long COVID (50), and that vasoconstriction occurs as a compensatory mechanism.…”

Parasympathetic activity is reduced during slow-wave sleep, but not resting wakefulness, in patients with chronic fatigue syndrome

“…For example, disrupted autonomic activity during deep sleep may also arise from habitual poor sleep, or emerge as a secondary symptom of reduced physical activity, which is common in patients with CFS. 55,56 Exploratory analyses indeed indicated a positive association between increased physical activity and higher HFnu HRV during NREM2 and REM stages of sleep, which may be a result of greater physical conditioning.…”