Orthostatic intolerance as a potential contributor to prolonged fatigue and inconsistent performance in elite swimmers

Abstract:

Background: Athletic underperformance is characterized by fatigue and an inability to sustain a consistent exercise workload. We describe five elite swimmers with prolonged fatigue and athletic underperformance. Based on our work in myalgic encephalomyelitis /chronic fatigue syndrome, we focused on orthostatic intolerance as a possible contributor to symptoms.

Methods: Participants were referred for evaluation of fatigue and underperformance to the Chronic Fatigue Clinic at the Johns Hopkins Children’s Center. All patients were evaluated for overtraining syndrome, as well as for features commonly seen in myalgic encephalomyelitis/chronic fatigue syndrome. The latter included joint hypermobility, orthostatic intolerance, and non-IgE mediated milk protein intolerance. Orthostatic intolerance was tested by performing a ten-minute passive standing test or a head-up tilt table test.

Results: Orthostatic testing provoked fatigue and other symptoms in all five swimmers, two of whom met heart rate criteria for postural tachycardia syndrome. Treatment was individualized, primarily consisting of an increased intake of sodium chloride and fluids to address orthostasis. All patients experienced a relatively prompt improvement in fatigue and other orthostatic symptoms and were able to either return to their expected level of performance or improve their practice consistency.

Conclusions: Orthostatic intolerance was an easily measured and treatable contributor to athletic underperformance in the five elite swimmers we describe. We suggest that passive standing tests or formal tilt table tests be incorporated into the clinical evaluation of athletes with fatigue and underperformance as well as into scientific studies of this topic. Recognition and treatment of orthostatic intolerance provides a new avenue for improving outcomes in underperforming athletes.

Source: Petracek LS, Eastin EF, Rowe IR, Rowe PC. Orthostatic intolerance as a potential contributor to prolonged fatigue and inconsistent performance in elite swimmers. BMC Sports Sci Med Rehabil. 2022 Jul 23;14(1):139. doi: 10.1186/s13102-022-00529-8. PMID: 35870963. https://bmcsportsscimedrehabil.biomedcentral.com/articles/10.1186/s13102-022-00529-8 (Full text)

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

Abstract:

Background: Some patients with acute COVID-19 are left with persistent, debilitating fatigue, cognitive impairment (“brain fog”), orthostatic intolerance (OI) and other symptoms (“Long COVID”). Many of the symptoms are like those of other post-infectious fatigue syndromes and may meet criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Common diagnostic laboratory tests are often unrevealing.

Methods: We evaluated whether a simple, standardized, office-based test of OI, the 10-min NASA Lean Test (NLT), would aggravate symptoms and produce objective hemodynamic and cognitive abnormalities, the latter being evaluated by a simple smart phone-based app.

Participants: People with Long COVID (N = 42), ME/CFS (N = 26) and healthy control subjects (N = 20) were studied just before, during, immediately after, 2 and 7 days following completion of the NLT.

Results: The NLT provoked a worsening of symptoms in the two patient groups but not in healthy control subjects, and the severity of all symptoms was similar and significantly worse in the two patient groups than in the control subjects (p < 0.001). In the two patient groups, particularly those with Long COVID, the NLT provoked a marked and progressive narrowing in the pulse pressure. All three cognitive measures of reaction time worsened in the two patient groups immediately following the NLT, compared to the healthy control subjects, particularly in the Procedural Reaction Time (p < 0.01).

Conclusions: A test of orthostatic stress easily performed in an office setting reveals different symptomatic, hemodynamic and cognitive abnormalities in people with Long COVID and ME/CFS, compared to healthy control subjects. Thus, an orthostatic challenge easily performed in an office setting, and the use of a smart phone app to assess cognition, can provide objective confirmation of the orthostatic intolerance and brain fog reported by patients with Long COVID and ME/CFS.

Source: Vernon SD, Funk S, Bateman L, Stoddard GJ, Hammer S, Sullivan K, Bell J, Abbaszadeh S, Lipkin WI, Komaroff AL. Orthostatic Challenge Causes Distinctive Symptomatic, Hemodynamic and Cognitive Responses in Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Front Med (Lausanne). 2022 Jun 23;9:917019. doi: 10.3389/fmed.2022.917019. PMID: 35847821; PMCID: PMC9285104. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9285104/ (Full text)

The higher resting heart rate in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients compared to healthy controls: relation with stroke volumes

Abstract:

Introduction: In patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) a higher-than-normal resting heart rate has been reported in a number of studies. As heart rate is linked to stroke volume, the present study explored the relationship between the supine heart rate and stroke volume index in healthy controls and in ME/CFS patients. Moreover, as patients with a postural orthostatic tachycardia syndrome (POTS) during tilt testing, have a higher supine heart rate than patients with a normal heart rate and blood pressure response during tilting, these two patient groups were also compared.

Methods and results: From a database of individuals who had undergone tilt-testing, including supine Doppler measurements for stroke volume index calculation, we selected ME/CFS patients and healthy controls without evidence of hypotension or syncope. 474 ME/CFS patients were analyzed, 314 with a normal heart rate and blood pressure response and 160 with POTS during tilt-testing, and 56 healthy controls. Resting stroke volume indices were similar between the 3 groups. All 3 groups had an inverse relation between the resting stroke volume index and resting heart rate (all p<0.0001). The slope of the relation was not significantly different between the 3 groups. Using the upper limit of the 95% prediction interval for the heart rate of healthy controls, 46 (15%) of patients with a normal heart rate and blood pressure response had a resting heart rate above the upper limit, 248 (85%) a heart rate between the upper and lower limit. In 47 (29%) patients developing POTS the resting heart rate was above the upper limit, and in 113 (71%) patients within the upper limit and lower limit. This distribution was significantly different between the two patient groups (p=0.0001).

Conclusion: Patients and healthy controls showed a significant and inverse relation between the SVI and heart rate at rest. Already at rest heart rate in patients developing POTS during tilt-testing were higher compared to the patients with a normal heart rate and blood pressure response per unit of SVI, but the heart rate of the majority of all patients fell within the limits of normal of healthy controls. The difference of patients with heart rate above the upper limit versus between the upper limit and lower limit deserves further investigation and may have therapeutic implications.

Source: VAN CAMPEN, C (Linda) M.C.; VISSER, Frans C.. The higher resting heart rate in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients compared to healthy controls: relation with stroke volumes.. Medical Research Archives, [S.l.], v. 10, n. 6, june 2022. ISSN 2375-1924. Available at: https://esmed.org/MRA/mra/article/view/2891. Date accessed: 17 july 2022. doi: https://doi.org/10.18103/mra.v10i6.2891.

Autonomic function testing in long-COVID syndrome patients with orthostatic intolerance

Abstract:

The association between dysautonomia and long-COVID syndrome has gained considerable interest. This study retrospectively characterized the findings of autonomic reflex screen (ARS) in long-COVID patients presenting with orthostatic intolerance (OI). Fourteen patients were identified. All patients had normal cardiovagal function and 2 patients had abnormal sudomotor function. The head-up tilt table (HUTT) was significantly abnormal in 3 patients showing postural orthostatic tachycardia syndrome (POTS). CASS ranged from 0 to 2. The most common clinical scenario was symptoms of orthostatic intolerance without demonstrable HUTT orthostatic tachycardia or orthostatic hypotension (OH) (n = 8, 57 %). In our case series, most long-COVID patients presenting to our laboratory with OI had no significant HUTT abnormalities; only 3 patients met the criteria for POTS.

Source: Eldokla AM, Ali ST. Autonomic function testing in long-COVID syndrome patients with orthostatic intolerance. Auton Neurosci. 2022 Jun 2;241:102997. doi: 10.1016/j.autneu.2022.102997. Epub ahead of print. PMID: 35679657. https://pubmed.ncbi.nlm.nih.gov/35679657/

Post-Acute Sequelae of SARS-CoV-2 infection (PASC) – Lessons Learned From a Coordinated Health Systems Response

Abstract:

Objective: To outline a consensus designed process for triaging and managing patients with Post COVID syndrome at the Mayo Clinic.

Patients and methods: We convened a central multidisciplinary team including members from General Internal Medicine, Occupational Medicine, Physical Medicine & Rehabilitation, Psychology, Allergy and Immunology, Infectious Disease, Pulmonology, Neurology, Cardiology, Pediatrics and Otorhinolaryngology, with membership from all the Mayo Clinic sites in Arizona, Florida, Iowa, Minnesota, and Wisconsin.

Results: Consensus recommendations were made for best practice guidelines on triaging and managing patients. Several innovations were agreed upon including a PASC specific appointment request form for data collection, a bio-registry, a bio-repository, and a PASC specific treatment program.

Conclusions: Given that each clinical site had individual clinical practices, these recommendations were implemented using different models, which may provide broad applicability to other clinical settings.

Source: Ganesh R, Vanichkachorn GS, Munipalli B, Hanson SN, Abu Dabrh AM, Croghan IT, Dawson NL, Hurt RT. Post-Acute Sequelae of SARS-CoV-2 infection (PASC) – Lessons Learned From a Coordinated Health Systems Response. Mayo Clin Proc Innov Qual Outcomes. 2022 Jun 1. doi: 10.1016/j.mayocpiqo.2022.05.007. Epub ahead of print. PMID: 35669936; PMCID: PMC9156955. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9156955/ (Full text)

A case series of cutaneous phosphorylated α-synuclein in Long-COVID POTS

Dear Editors,

As case numbers of coronavirus disease 19 (COVID-19) increase, chronic symptoms, including those of autonomic dysfunction, are being reported with increasing frequency [], leading to the diagnosis of post-acute sequelae of COVID-19 (PASC), or Long-COVID. In addition, small fiber neuropathy (SFN) has been reported after viral infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) []. These associations have prompted our group to systematically perform autonomic testing and skin biopsies in a cohort of patients who have developed postural tachycardia syndrome (POTS) as a consequence of PASC (Long-COVID POTS). As part of this evaluation, all skin biopsy samples undergo immunohistochemical analysis of both intraepidermal nerve fiber density (IENFD) and phosphorylated α-synuclein (p-syn) [], the pathological form of α-synuclein associated with the neurodegenerative diseases of Parkinson’s disease (PD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and pure autonomic failure (PAF), as well as isolated REM sleep behavior disorder (iRBD), a prodromal manifestation of synucleinopathy for the majority of patients.

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Source: Miglis MG, Seliger J, Shaik R, Gibbons CH. A case series of cutaneous phosphorylated α-synuclein in Long-COVID POTS. Clin Auton Res. 2022 May 16:1–4. doi: 10.1007/s10286-022-00867-0. Epub ahead of print. PMID: 35570247; PMCID: PMC9108014. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9108014/ (Full text)

Autonomic dysfunction and post-COVID-19 syndrome: A still elusive link

Editorial:

Infection from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing the long-lasting pandemic coronavirus disease 2019 (COVID-19), with dramatic clinical, social, and economic implications. Importantly, evolving experience consistently shows that, in addition to issues related to the acute phase, patients who recover from COVID-19 may present a wide variety of bothersome symptoms, which may be debilitating and significantly impair their quality of life. This condition, when it persists beyond 12 weeks after recovery, is defined as “post–COVID-19” or “long COVID-19” syndrome.

Some of the symptoms, including tachycardia/palpitations, chest pain, fatigue, and dyspnea with reduced effort tolerance, suggest a possible cardiovascular cause, whereas others (eg, muscle and/or joint pain, headache, memory loss, nausea, mood disturbances) suggest involvement of other systems. Symptoms may occur independently of the severity of COVID-19, although patients with more severe symptoms in the acute phase experience a higher rate of symptom persistence during follow-up. , 

Importantly, careful diagnostic assessment usually fails to identify specific causes of post–COVID-19 syndrome. However, it has been suggested that at least some post–COVID-19 symptoms, including those of potential cardiovascular origin, might be related to abnormalities of the autonomic nervous system (ANS). The pathophysiological mechanisms responsible for ANS impairment remain speculative and might include direct damage of the ANS (ganglia and/or nerve terminations) by the virus, a toxic effect of inflammatory cytokines released during the acute infection, and an immune-mediated response triggered by some viral component(s). ,  Independent of the mechanism, the possibility of ANS involvement in SARS-CoV-2 infection is supported by the frequent occurrence of neurologic symptoms (eg, anosmia, dysgeusia) as well as the sporadic occurrence of clinical conditions typically related to ANS dysfunction (eg, orthostatic hypotension, orthostatic tachycardia) in post–COVID-19 syndrome. Furthermore, patients with COVID-19, compared to healthy subjects, have been found to show reduced heart rate variability (HRV) parameters 20 weeks after recovery from the illness. However, a pathogenetic relationship between dysautonomia and post–COVID-19 syndrome remains to be demonstrated. Establishing such a relationship would be of importance because it might help guide the management of this clinical condition.

The study by Ladlow et al in this issue of Heart Rhythm Journal is welcome because it attempts to clarify whether any association exists between dysautonomia and symptoms, as well as objective evidence of exercise intolerance, in patients with post–COVID-19 syndrome. In their study, Ladlow et al enrolled 205 patients referred to a post–COVID-19 clinic who fulfilled specific eligibility criteria (hospitalization and desaturation ≤95% on a Harvard step test or chest pain with electrocardiographic [ECG] changes during acute illness and life-limiting symptoms persisting for >12 weeks). All patients underwent bicycle cardiopulmonary exercise testing (CPET) and were divided into 1 of 2 groups according to evidence or no evidence of dysautonomia.

Dysautonomia was diagnosed based on 3 heart rate (HR) parameters that Jouven et al found to be associated with total mortality and sudden death in a population of asymptomatic subjects: (1) resting HR >75 bpm; (2) increase in HR during exercise <89 bpm; and (3) HR reduction <25 bpm during the first minute of recovery from peak exercise. HRV was also assessed by calculating the root mean square of the squared differences of adjacent RR intervals (RMSSD) on a 1-minute 12-lead ECG at rest and on 30-second ECGs during the first 3 minutes of recovery after peak exercise.

Patients were studied 183 ± 77 days (∼6 months) from COVID-19 disease, and dysautonomia was found in 51 patients (25%). Per definition, these patients had higher HR at rest (95 ± 12 bpm vs 81 ± 12 bpm; P <.001) and lower HR increase during CPET (75 ± 12 bpm vs 96 ± 13 bpm; P <.001) and HR recovery after peak exercise (17 ± 4 bpm vs 31 ± 17 bpm; P <.001) compared to those without dysautonomia.

Patients with dysautonomia were older, had a higher body mass index (BMI) (P = .013) and waist circumference (WC) (P = .003), and had a lower basal RMSSD (P <.001). Furthermore, at rest, dysautonomic patients showed a higher breathing rate (P = .006) and lower forced vital capacity (P = .031), forced expiratory volume in 1 second (P = .036), and ventilatory efficiency (Ve/Vco 2) (P = .036).

When assessing symptoms that showed prevalence >25%, a significant association with dysautonomia was found for low mood (P = .007), headache (P = .026), and poor attention (P = .047). However, other symptoms, including some of potential cardiovascular origin (eg, shortness of breath, fatigue), showed no significant association with dysautonomia.

Patients with dysautonomia, however, showed a lower performance on CPET. In particular, HR at peak exercise (170 ± 13 bpm vs 177 ± 15 bpm; P = .003), maximal work rate (219 ± 37 W vs 253 ± 52 W; P <.001), and maximal oxygen consumption (VO2) (30.6 ± 5.5 mL/kg/min vs 35.8 ± 7.6 mL/kg/min; P <.001) all were significantly lower in patients with dysautonomia than in those without dysautonomia, suggesting a role of ANS dysfunction in their physical limitation.

Ladlow et al should be congratulated for performing this large study on post–COVID-19 syndrome. However, possible alternative interpretations of the data suggest caution in deriving definitive conclusions from their results.

Although the study shows the lack of significant relationship between dysautonomia and most post–COVID-19 symptoms, including, in particular, some symptoms of possible cardiovascular origin, the method applied to identify patients with an impairment of ANS function presents some limitations. Both higher HR at rest and lower HR recovery after exercise suggest an imbalance of sympathovagal tone toward adrenergic predominance in their patients with dysautonomia. However, rather than reflecting a primary impairment of the ANS, these findings simply might have been related to differences between the 2 groups with regard to some basal clinical characteristics, including higher BMI/WC, lower efficiency in respiratory function, and lower mood in dysautonomic patients. In addition, the lower increase in HR during maximal exercise in patients with dysautonomia might have been a mere consequence of their having a higher HR at rest and, given their older age, a lower maximal theoretical HR for age. The percent of predicted maximal HR for age achieved during CPET, in fact, did not differ between the 2 groups. The possibility that the differences in HR behavior might have not been related to a primary abnormality of the ANS is also suggested by the fact that, despite the basal difference, RMSSD values were similar during exercise recovery in the 2 groups of patients, suggesting a similar ANS response to exercise interruption in the 2 groups.

Future studies should clarify whether different results regarding the relationship between ANS dysfunction and post–COVID-19 symptoms might be obtained using more comprehensive and better validated methods for the diagnosis of ANS dysfunction, such as standard tests of autonomic function and HRV assessed from its multiple (short-term and long-term) components.

Of note, although the results of CPET in the study by Ladlow et al suggest lower performance by patients classified with dysautonomia, exercise tolerance was largely normal in these subjects, who achieved >100% of the predicted maximal oxygen consumption and an average maximal work rate of 219 W, with only small differences compared to patients without dysautonomia, possibly explained, again, and at least in part, by some demographic (age) and clinical (BMI, respiratory function) differences.

In conclusion, the study by Ladlow et al provides interesting data on the clinical characteristics and objective physical performance of patients with post–COVID-19 syndrome. However, the role of ANS in determining symptoms (particularly those of potential cardiovascular origin) and physical limitation in these patients still has not been fully elucidated by their data, making necessary further studies applying more comprehensive and valuable methods for the assessment of ANS function.

Source: Lanza GA. Autonomic dysfunction and post-COVID-19 syndrome: A still elusive link. Heart Rhythm. 2022 Apr;19(4):621-622. doi: 10.1016/j.hrthm.2021.12.027. Epub 2021 Dec 28. PMID: 34968741; PMCID: PMC8712711. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8712711/ (Full study)

Platelet Storage Pool Deficiency and Elevated Inflammatory Biomarkers Are Prevalent in Postural Orthostatic Tachycardia Syndrome

Abstract:

A significant number of postural orthostatic tachycardia syndrome (POTS) patients have platelet delta granule storage pool deficiency (δ-SPD).

The etiology of POTS is unknown but a number of laboratories, including ours, have reported elevations of G-protein-coupled adrenergic receptor and muscarinic acetylcholine receptor autoantibodies in POTS patients, detected by a variety of techniques, suggesting that the disorder is an autoimmune condition. Thus, it could also be considered an inflammatory disease.

In a pilot study, we investigated a limited number of platelet-related cytokines and chemokines and discovered many that were elevated.

This case–control study validates our pilot study results that POTS patients have an activated innate immune system.

Plasma of 35 POTS patients and 35 patients with unexplained bleeding symptoms and categorized as “non-POTS” subjects was analyzed by multiplex flow cytometry to quantify 16 different innate immune system cytokines and chemokines. Electron microscopy was used to quantify platelet dense granules.

Ten of 16 biomarkers of inflammation were elevated in plasma from POTS patients compared to non-POTS subjects, with most of the differences extremely significant, with p values < 0.0001.

Of particular interest were elevations of IL-1β and IL-18 and decreased or normal levels of type 1 interferons in POTS patients, suggesting that the etiology of POTS might be autoinflammatory.

All POTS patients had δ-SPD. With a growing body of evidence that POTS is an autoimmune disease and having elevations of the innate immune system, our results suggest a potential T-cell-mediated autoimmunity in POTS characteristic of a mixed-pattern inflammatory disease similar to rheumatoid arthritis.

Source: Gunning WT, Kramer PM, Cichocki JA, Karabin BL, Khuder SA, Grubb BP. Platelet Storage Pool Deficiency and Elevated Inflammatory Biomarkers Are Prevalent in Postural Orthostatic Tachycardia Syndrome. Cells. 2022; 11(5):774. https://doi.org/10.3390/cells11050774  https://www.mdpi.com/2073-4409/11/5/774/htm (Full text)

Psychogenic Pseudosyncope: Real or Imaginary? Results from a Case-Control Study in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Patients

Abstract:

Background and objectives: Orthostatic intolerance (OI) is a clinical condition in which symptoms worsen upon assuming and maintaining upright posture and are ameliorated by recumbency. OI has a high prevalence in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Exact numbers on syncopal spells especially if they are on a weekly or even daily basis are not described. Although not a frequent phenomenon, this symptomatology is of very high burden to the patient if present. To explore whether patients with very frequent (pre)syncope spells diagnosed elsewhere with conversion or psychogenic pseudosyncope (PPS) might have another explanation of their fainting spells than behavioral psychiatric disorders, we performed a case-control study comparing ME/CFS patients with and without PPS spells.

Methods and results: We performed a case-control study in 30 ME/CFS patients diagnosed elsewhere with PPS and compared them with 30 control ME/CFS patients without syncopal spells. Cases were gender, age and ME/CFS disease duration matched. Each underwent a tilt test with extracranial Doppler measurements for cerebral blood flow (CBF). ME/CFS cases with PPS had a significant larger CBF reduction at end tilt than controls: 39 (6)% vs. 25 (4)%; (p < 0.0001). Cases had more severe disease compared with controls (chi-square p < 0.01 and had a p = 0.01) for more postural orthostatic tachycardia syndrome in cases compared with controls. PETCO2 end-tilt differed also, but the magnitude of difference was smaller than compared with the CBF reduction: there were no differences in heart rate and blood pressure at either end-tilt testing period. Compared with the test with the stockings off, the mean percentage reduction in cardiac output during the test with compression stockings on was lower, 25 (5) mmHg versus 29 (4) mmHg (p < 0.005).

Conclusions: This study demonstrates that in ME/CFS patients suspected of having PPS, or conversion, CBF measurements end-tilt show a large decline compared with a control group of ME/CFS patients. Therefore, hypoperfusion offers an explanation of the orthostatic intolerance and syncopal spells in these patients, where it is clear that origin might not be behavioral or psychogenic, but have a clear somatic pathophysiologic background.

Source: van Campen CLMC, Visser FC. Psychogenic Pseudosyncope: Real or Imaginary? Results from a Case-Control Study in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Patients. Medicina (Kaunas). 2022 Jan 9;58(1):98. doi: 10.3390/medicina58010098. PMID: 35056406. https://pubmed.ncbi.nlm.nih.gov/35056406/

Orthostatic Symptoms and Reductions in Cerebral Blood Flow in Long‐Haul COVID‐19 Patients: Similarities with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Background and Objectives: Symptoms and hemodynamic findings during orthostatic stress have been reported in both long-haul COVID-19 and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), but little work has directly compared patients from these two groups. To investigate the overlap in these clinical phenotypes, we compared orthostatic symptoms in daily life and during head-up tilt, heart rate and blood pressure responses to tilt, and reductions in cerebral blood flow in response to orthostatic stress in long-haul COVID-19 patients, ME/CFS controls, and healthy controls.
Materials and Methods: We compared 10 consecutive long-haul COVID-19 cases with 20 age- and gender-matched ME/CFS controls with postural tachycardia syndrome (POTS) during head-up tilt, 20 age- and gender-matched ME/CFS controls with a normal heart rate and blood pressure response to head-up tilt, and 10 age- and gender-matched healthy controls. Identical symptom questionnaires and tilt test procedures were used for all groups, including measurement of cerebral blood flow and cardiac index during the orthostatic stress.
Results: There were no significant differences in ME/CFS symptom prevalence between the long-haul COVID-19 patients and the ME/CFS patients. All long-haul COVID-19 patients developed POTS during tilt. Cerebral blood flow and cardiac index were more significantly reduced in the three patient groups compared with the healthy controls. Cardiac index reduction was not different between the three patient groups. The cerebral blood flow reduction was larger in the long-haul COVID-19 patients compared with the ME/CFS patients with a normal heart rate and blood pressure response.
Conclusions: The symptoms of long-haul COVID-19 are similar to those of ME/CFS patients, as is the response to tilt testing. Cerebral blood flow and cardiac index reductions during tilt were more severely impaired than in many patients with ME/CFS. The finding of early-onset orthostatic intolerance symptoms, and the high pre-illness physical activity level of the long-haul COVID-19 patients, makes it unlikely that POTS in this group is due to deconditioning. These data suggest that similar to SARS-CoV-1, SARS-CoV-2 infection acts as a trigger for the development of ME/CFS.
Source: Campen CMCv, Rowe PC, Visser FC. Orthostatic Symptoms and Reductions in Cerebral Blood Flow in Long-Haul COVID-19 Patients: Similarities with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Medicina. 2022; 58(1):28. https://doi.org/10.3390/medicina58010028  (Full text)