Evidence of altered cardiac autonomic regulation in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract

Background:Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex condition with no reliable diagnostic biomarkers. Studies have shown evidence of autonomic dysfunction in patients with ME/CFS, but results have been equivocal. Heart rate (HR) parameters can reflect changes in autonomic function in healthy individuals; however, this has not been thoroughly evaluated in ME/CFS.Methods:A systematic database search for case-control literature was performed. Meta-analysis was performed to determine differences in HR parameters between ME/CFS patients and controls.Results:Sixty-four articles were included in the systematic review. HR parameters assessed in ME/CFS patients and controls were grouped into ten categories: resting HR (RHR), maximal HR (HRmax), HR during submaximal exercise, HR response to head-up tilt testing (HRtilt), resting HR variability (HRVrest), HR variability during head-up tilt testing (HRVtilt), orthostatic HR response (HROR), HR during mental task(s) (HRmentaltask), daily average HR (HRdailyaverage), and HR recovery (HRR) Meta-analysis revealed RHR (MD ± 95% CI = 4.14 ± 1.38, P < .001), HRtilt (SMD ± 95% CI = 0.92 ± 0.24, P < .001), HROR (0.50 ± 0.27, P < .001), and the ratio of low frequency power to high frequency power of HRVrest (0.39 ± 0.22, P < .001) were higher in ME/CFS patients compared to controls, while HRmax (MD ± 95% CI = –13.81 ± 4.15, P < .001), HR at anaerobic threshold (SMD ± 95% CI = –0.44 ± 0.30, P = 0.005) and the high frequency portion of HRVrest (–0.34 ± 0.22, P = .002) were lower in ME/CFS patients.Conclusions:The differences in HR parameters identified by the meta-analysis indicate that ME/CFS patients have altered autonomic cardiac regulation when compared to healthy controls. These alterations in HR parameters may be symptomatic of the condition.

Potential causal factors of CFS/ME: a concise and systematic scoping review of factors researched

“…Our scoping review included 1161 studies, and although our scope was larger than the 2008 review, there is a clear increase in research in the field. However, our findings echo the conclusions of numerous recent reviews [ 3 , 12 , 15 , 16 , 23 , 27 , 29 ], namely, that our confidence in the evidence is too low to draw conclusions about causal factors. This is due to the preponderance of relatively weak study designs.…”

“…The vastness of the research field on etiological factors reflects the variety of causal hypotheses [ 19 ], and in the past two years alone, numerous systematic reviews have been published examining distinct causal factors such as immunological [ 12 , 16 , 29 ], metabolic [ 15 , 23 ], circulatory [ 27 ], and epigenetic factors [ 3 ]. In 2016, the Research Council of Norway selected the CFS/ME field as the pilot field for a research priority setting partnership strategy, in which patients, next of kin, and related organizations prioritized research questions for commissioned research [ 14 ].…”

Acupuncture therapy on chronic fatigue syndrome based on radar plot

“…[ 3 ] Symptoms of tolerance, pain, flu-like physical or mental activity abnormalities are related to the central nervous system, autonomic nervous system, digestive system, endocrine metabolism, immune regulation, and other systems. [ 4 , 5 ] International research on the etiology, pathogenesis, and treatment of chronic fatigue syndrome (CFS) involves more than 20 commonly used case definition standards. [ 2 ] The prevalence of CFS/ME ranges from 0.1% to 7.62%, affecting different ages, races, and socioeconomic groups.…”

Cardiac Dimensions and Function are Not Altered among Females with the Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

“…Notably, the differences in lactate accumulation and gas exchange threshold between the patients and controls increased when they were re-tested after 24 h. Neither resting nor maximum heart rate at peak exercise differed significantly between the groups [ 3 ]. Such alterations in the oxidative vs. glycolytic energy balance might be due to intrinsic abnormalities in various energy-yielding metabolic pathways and/or reduced tissue oxygen supply [ 1 , 4 ].…”

“…In support of this, Miwa et al have shown that ME patients often have small hearts as measured using chest roentgenograms and cardiac dysfunction evaluated with echocardiography [ 6 ]. Corroborating this notion of impaired cardiovascular capacity in ME/CFS are data from a systematic meta-analysis showing differences in various heart-rate indices in ME/CFS compared to healthy controls [ 4 ]. Notwithstanding these findings, detailed studies of cardiac function in rigorously defined ME/CFS cohorts are scarce.…”