Tag: hypoperfusion

Microvascular Capillary and Precapillary Cardiovascular Disturbances Strongly Interact to Severely Affect Tissue Perfusion and Mitochondrial Function in ME/CFS Evolving from the Post COVID-19 Syndrome

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a frequent, debilitating and still enigmatic disease. There is a broad overlap in the symptomatology of ME/CFS and the Post-COVID Syndrome (PCS). A fraction of the PCS patients develops the full clinical picture of ME/CFS.
New observations in microvessels and blood from patients suffering from PCS have appeared and include microclots and malformed pathological blood cells. Capillary blood flow is impaired not only by pathological blood components but also by prothrombotic changes in the vascular wall, endothelial dysfunction, and expression of adhesion molecules in the capillaries. These disturbances can finally cause a low capillary flow and even capillary stasis. A low cardiac stroke volume due to hypovolemia and the inability of the capacitance vessels to adequately constrict to deliver the necessary cardiac preload generate an unfavorable low precapillary perfusion pressure.
Furthermore, a predominance of vasoconstrictor over vasodilator influences exists, in which sympathetic hyperactivity and endothelial dysfunction play a strong role, causing constriction of resistance vessels and of precapillary sphincters which leads to a fall in capillary pressure behind the sphincters. The interaction of these two precapillary cardiovascular mechanisms causing a low capillary perfusion pressure is hemodynamically highly unfavorable in the presence of a primary capillary stasis already caused by the pathological blood components and their interaction with the capillary wall, to severely impair organ perfusion.
The detrimental coincidence of the microcirculatory with the precapillary cardiovascular disturbances may constitute the key disturbance of the Post-COVID-19 syndrome and finally lead to ME/CFS in pre-disposed patients because the interaction causes a particular kind of perfusion disturbance – capillary ischemia-reperfusion – which has a high potential of causing mitochondrial dysfunction by inducing sodium- and calcium-overload in skeletal muscles. The latter in turns worsens the vascular situation by the generation of reactive oxygen species to close a vicious cycle from which the patient can hardly escape.
Source: Wirth, K.J.; Löhn, M. Microvascular Capillary and Precapillary Cardiovascular Disturbances Strongly Interact to Severely Affect Tissue Perfusion and Mitochondrial Function in ME/CFS Evolving from the Post COVID-19 Syndrome. Preprints 2023, 2023120791. https://doi.org/10.20944/preprints202312.0791.v1  https://www.preprints.org/manuscript/202312.0791/v1 (Full text available as PDF file)

Long COVID is primarily a Spike protein Induced Thrombotic Vasculitis

Abstract:

Long COVID describes an array of often debilitating symptoms in the aftermath of SARS-CoV-2 infection, with similar symptomatology affecting some people post-vaccination. With an estimated > 200 million Long COVID patients worldwide and cases still rising, the effects on quality of life and the economy are significant, thus warranting urgent attention to understand the pathophysiology. Herein we describe our perspective that Long COVID is a continuation of acute COVID-19 pathology, whereby coagulopathy is the main driver of disease and can cause or exacerbate other pathologies common in Long COVID, such as mast cell activation syndrome and dysautonomia.
Considering the SARS-CoV-2 spike protein can independently induce fibrinaloid microclots, platelet activation, and endotheliitis, we predict that persistent spike protein will be a key mechanism driving the continued coagulopathy in Long COVID. We discuss several treatment targets to address the coagulopathy, and predict that (particularly early) treatment with combination anticoagulant and antiplatelet drugs will bring significant relief to many patients, supported by a case study. To help focus attention on such treatment targets, we propose Long COVID should be referred to as Spike protein Induced Thrombotic Vasculitis (SITV). These ideas require urgent testing, especially as the world tries to co-exist with COVID-19.

Source: Kerr R, Carroll HA. Long COVID is primarily a Spike protein Induced Thrombotic Vasculitis. Research Square; 2023. DOI: 10.21203/rs.3.rs-2939263/v1. https://assets.researchsquare.com/files/rs-2939263/v1_covered_7190a867-1475-4b57-b220-716a953649f1.pdf?c=1684433225 (Full text)

Pulmonary circulation abnormalities in post-acute COVID-19 syndrome: dual-energy CT angiographic findings in 79 patients

Abstract:

Objectives: To evaluate the frequency and pattern of pulmonary vascular abnormalities in the year following COVID-19.

Methods: The study population included 79 patients remaining symptomatic more than 6 months after hospitalization for SARS-CoV-2 pneumonia who had been evaluated with dual-energy CT angiography.

Results: Morphologic images showed CT features of (a) acute (2/79; 2.5%) and focal chronic (4/79; 5%) PE; and (b) residual post COVID-19 lung infiltration (67/79; 85%). Lung perfusion was abnormal in 69 patients (87.4%). Perfusion abnormalities included (a) perfusion defects of 3 types: patchy defects (n = 60; 76%); areas of non-systematized hypoperfusion (n = 27; 34.2%); and/or PE-type defects (n = 14; 17.7%) seen with (2/14) and without (12/14) endoluminal filling defects; and (b) areas of increased perfusion in 59 patients (74.9%), superimposed on ground-glass opacities (58/59) and vascular tree-in-bud (5/59). PFTs were available in 10 patients with normal perfusion and in 55 patients with abnormal perfusion. The mean values of functional variables did not differ between the two subgroups with a trend toward lower DLCO in patients with abnormal perfusion (74.8 ± 16.7% vs 85.0 ± 8.1).

Conclusion: Delayed follow-up showed CT features of acute and chronic PE but also two types of perfusion abnormalities suggestive of persistent hypercoagulability as well as unresolved/sequelae of microangiopathy.

Clinical relevance statement: Despite dramatic resolution of lung abnormalities seen during the acute phase of the disease, acute pulmonary embolism and alterations at the level of lung microcirculation can be identified in patients remaining symptomatic in the year following COVID-19.

Key points: • This study demonstrates newly developed proximal acute PE/thrombosis in the year following SARS-CoV-2 pneumonia. • Dual-energy CT lung perfusion identified perfusion defects and areas of increased iodine uptake abnormalities, suggestive of unresolved damage to lung microcirculation. • This study suggests a complementarity between HRCT and spectral imaging for proper understanding of post COVID-19 lung sequelae.

Source: Mohamed I, de Broucker V, Duhamel A, Giordano J, Ego A, Fonne N, Chenivesse C, Remy J, Remy-Jardin M. Pulmonary circulation abnormalities in post-acute COVID-19 syndrome: dual-energy CT angiographic findings in 79 patients. Eur Radiol. 2023 Apr 25:1–13. doi: 10.1007/s00330-023-09618-9. Epub ahead of print. PMID: 37145145; PMCID: PMC10129318. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10129318/ (Full text)

Cardiovascular and haematological pathology in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): A role for viruses

Abstract:

ME/CFS is a debilitating chronic condition that often develops after viral or bacterial infection. Insight from the study of Long COVID/Post Acute Sequelae of COVID-19 (PASC), the post-viral syndrome associated with SARS-CoV-2 infection, might prove to be useful for understanding pathophysiological mechanisms of ME/CFS. Disease presentation is similar between the two conditions, and a subset of Long COVID patients meet the diagnostic criteria for ME/CFS.

Since Long COVID is characterized by significant vascular pathology – including endothelial dysfunction, coagulopathy, and vascular dysregulation – the question of whether or not the same biological abnormalities are of significance in ME/CFS arises.

Cardiac abnormalities have for a while now been documented in ME/CFS cohorts, with recent studies demonstrating major deficits in cerebral blood flow, and hence vascular dysregulation. A growing body of research is demonstrating that ME/CFS is accompanied by platelet hyperactivation, anomalous clotting, a procoagulant phenotype, and endothelial dysfunction. Endothelial damage and dysregulated clotting can impair substance exchange between blood and tissues, and result in hypoperfusion, which may contribute to the manifestation of certain ME/CFS symptoms.

Here we review the ME/CFS literature to summarize cardiovascular and haematological findings documented in patients with the condition, and, in this context, briefly discuss the potential role of previously-implicated pathogens.

Overall, cardiac and haematological abnormalities are present within ME/CFS cohorts. While atherosclerotic heart disease is not significantly associated with ME/CFS, suboptimal cardiovascular function defined by reduced cardiac output, impaired cerebral blood flow, and vascular dysregulation are, and these abnormalities do not appear to be influenced by deconditioning. Rather, these cardiac abnormalities may result from dysfunction in the (autonomic) nervous system.

Plenty of recently published studies are demonstrating significant platelet hyperactivity and endothelial dysfunction in ME/CFS, as well as anomalous clotting processes. It is of particular importance to determine to what extent these cardiovascular and haematological abnormalities contribute to symptom severity, and if these two systems can be targeted for therapeutic purposes.

Viral reservoirs of herpesviruses exist in ME/CFS, and most likely contribute to cardiovascular and haematological dysfunction directly or indirectly. This review highlights the potential of studying cardiac functioning, the vasculature, and coagulation system in ME/CFS.

Source: Jean M. Nunes, Douglas B. Kell, Etheresia Pretorius. Cardiovascular and haematological pathology in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): A role for viruses. Blood reviews, 20 March 2023, 101075 [Epub ahead of print]  https://www.sciencedirect.com/science/article/pii/S0268960X2300036X (Full text)

A prospective observational study of post-COVID-19 chronic fatigue syndrome following the first pandemic wave in Germany and biomarkers associated with symptom severity

Abstract:

A subset of patients has long-lasting symptoms after mild to moderate Coronavirus disease 2019 (COVID-19). In a prospective observational cohort study, we analyze clinical and laboratory parameters in 42 post-COVID-19 syndrome patients (29 female/13 male, median age 36.5 years) with persistent moderate to severe fatigue and exertion intolerance six months following COVID-19. Further we evaluate an age- and sex-matched postinfectious non-COVID-19 myalgic encephalomyelitis/chronic fatigue syndrome cohort comparatively.

Most post-COVID-19 syndrome patients are moderately to severely impaired in daily live. 19 post-COVID-19 syndrome patients fulfill the 2003 Canadian Consensus Criteria for myalgic encephalomyelitis/chronic fatigue syndrome. Disease severity and symptom burden is similar in post-COVID-19 syndrome/myalgic encephalomyelitis/chronic fatigue syndrome and non-COVID-19/myalgic encephalomyelitis/chronic fatigue syndrome patients. Hand grip strength is diminished in most patients compared to normal values in healthy.

Association of hand grip strength with hemoglobin, interleukin 8 and C-reactive protein in post-COVID-19 syndrome/non-myalgic encephalomyelitis/chronic fatigue syndrome and with hemoglobin, N-terminal prohormone of brain natriuretic peptide, bilirubin, and ferritin in post-COVID-19 syndrome/myalgic encephalomyelitis/chronic fatigue syndrome may indicate low level inflammation and hypoperfusion as potential pathomechanisms.

Source: Kedor C, Freitag H, Meyer-Arndt L, Wittke K, Hanitsch LG, Zoller T, Steinbeis F, Haffke M, Rudolf G, Heidecker B, Bobbert T, Spranger J, Volk HD, Skurk C, Konietschke F, Paul F, Behrends U, Bellmann-Strobl J, Scheibenbogen C. A prospective observational study of post-COVID-19 chronic fatigue syndrome following the first pandemic wave in Germany and biomarkers associated with symptom severity. Nat Commun. 2022 Aug 30;13(1):5104. doi: 10.1038/s41467-022-32507-6. PMID: 36042189. https://www.nature.com/articles/s41467-022-32507-6 (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/

Post COVID-19 syndrome associated with orthostatic cerebral hypoperfusion syndrome, small fiber neuropathy and benefit of immunotherapy: a case report

Abstract:

Coronavirus disease (COVID-19) is a novel highly contagious infectious disease caused by the coronavirus SARS-CoV2. The virus affects the human respiratory and other systems, and presents mostly as acute respiratory syndrome with fever, fatigue, dry cough, myalgia and dyspnea. The clinical manifestations vary from no symptoms to multiple organ failure. Majority of patients fully recover. Several postinfectious presumably autoimmune complications of COVID-19 affecting the brain or peripheral large nerve fibers have been reported. This report describes a post COVID-19 patient who developed chronic fatigue, orthostatic dizziness and brain fog consistent with orthostatic hypoperfusion syndrome (OCHOS), a form of orthostatic intolerance, and painful small fiber neuropathy (SFN). Initially, the patient was diagnosed with. OCHOS (detected by the tilt test with transcranial Doppler monitoring) and SFN (confirmed by skin biopsy), and both OCHOS/SFN were attributed to Post Treatment Lyme Disease Syndrome of presumed autoimmune etiology. Patient recovered on symptomatic therapy. COVID-19 triggered exacerbation of OCHOS/SFN responded to immunotherapy with intravenous immunoglobulins. This case suggests that post COVID-19 syndrome may present as an autoimmune OCHOS/SFN and that early immunotherapy may be effective. Further studies are necessary to confirm the link between OCHOS/SFN and COVID-19 disease as well as to confirm the benefit of immunotherapy.

Source: Novak P. Post COVID-19 syndrome associated with orthostatic cerebral hypoperfusion syndrome, small fiber neuropathy and benefit of immunotherapy: a case report. eNeurologicalSci. 2020 Dec;21:100276. doi: 10.1016/j.ensci.2020.100276. Epub 2020 Sep 20. PMID: 32984564; PMCID: PMC7502253. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7502253/ (Full text)

Small heart with low cardiac output for orthostatic intolerance in patients with chronic fatigue syndrome

Abstract:

BACKGROUND: The etiology of chronic fatigue syndrome (CFS) is unknown. Orthostatic intolerance (OI) is common in CFS patients. Recently, small heart with low cardiac output has been postulated to be related to the genesis of both CFS and OI.

HYPOTHESIS: Small heart is associated with OI in patients with CFS.

METHODS: Study CFS patients were divided into groups of 26 (57%) CFSOI(+) and 20 (43%) CFSOI(-) according to the presence or absence of OI. In addition, 11 OI patients and 27 age- and sex-matched control subjects were studied. Left ventricular (LV) dimensions and function were determined echocardiographically.

RESULTS: The mean values of cardiothoracic ratio, systemic systolic and diastolic pressures, LV end-diastolic dimension, LV end-systolic dimension, stroke volume index, cardiac index, and LV mass index were all significantly smaller in CFSOI(+) patients than in CFSOI(-) patients and healthy controls, and also in OI patients than in controls. A smaller LV end-diastolic dimension (<40 mm) was significantly (P<0.05) more prevalently noted in CFSOI(+) (54%) and OI (45%) than in CFSOI(-) (5%) and controls (4%). A lower cardiac index (<2 L/min/mm(2)) was more prevalent in CFSOI(+) (65%) than in CFSOI(-) (5%, P<0.01), OI (27%), and controls (11%, P<0.01).

CONCLUSIONS: A small size of LV with low cardiac output was noted in OI, and its degree was more pronounced in CFSOI(+). A small heart appears to be related to the genesis of OI and CFS via both cerebral and systemic hypoperfusion. CFSOI(+) seems to constitute a well-defined and predominant subgroup of CFS.

© 2011 Wiley Periodicals, Inc.

 

Source: Miwa K, Fujita M. Small heart with low cardiac output for orthostatic intolerance in patients with chronic fatigue syndrome. Clin Cardiol. 2011 Dec;34(12):782-6. doi: 10.1002/clc.20962. Epub 2011 Nov 28. http://onlinelibrary.wiley.com/doi/10.1002/clc.20962/full (Full article)

 

Single-photon emission computerized tomography and neurocognitive function in patients with chronic fatigue syndrome

Erratum in: Psychosom Med. 2003 Mar-Apr;65(2):210.

 

Abstract:

OBJECTIVE: The purposes of this study were to compare functional imaging under control and experimental conditions among patients with chronic fatigue syndrome (CFS) and healthy persons and to examine perceived and objective performance on a test of attention and working memory previously found to be difficult for persons with CFS.

METHODS: Single-photon emission computerized tomography scans were completed on 15 subjects with CFS and 15 healthy persons twice: at rest and when performing the Paced Auditory Serial Addition Test (PASAT).

RESULTS: No group differences were found for performance on the PASAT despite CFS subjects’ perceptions of exerting more mental effort to perform the task than healthy subjects. Inspection of the aggregate scans by group and task suggested a pattern of diffuse regional cerebral blood flow among subjects with CFS in comparison with the more focal pattern of regional cerebral blood flow seen among healthy subjects. Between-group region-of-interest analysis revealed that although CFS subjects showed less perfusion in the anterior cingulate region, the change in CFS subjects’ activation of the left anterior cingulate region during the PASAT was greater than that observed for healthy subjects. The differences were not attributable to lesser effort by the subjects with CFS, confounding effects of mood perturbation, or to poorer performance on the experimental task.

CONCLUSIONS: Further research regarding CFS subjects’ diffuse cerebral perfusion and its relationship to inefficient neuropsychological performance is warranted.

 

Source: Schmaling KB, Lewis DH, Fiedelak JI, Mahurin R, Buchwald DS. Single-photon emission computerized tomography and neurocognitive function in patients with chronic fatigue syndrome. Psychosom Med. 2003 Jan-Feb;65(1):129-36. http://www.ncbi.nlm.nih.gov/pubmed/12554824

 

Role of impaired lower-limb venous innervation in the pathogenesis of the chronic fatigue syndrome

Abstract:

BACKGROUND: In patients with acute orthostatic hypotension, there is excessive pooling of blood in the legs, which may result from the strikingly subnormal compliance that is demonstrable in the pedal veins during norepinephrine infusion. The common occurrence of delayed orthostatic hypotension and/or tachycardia in the chronic fatigue syndrome (CFS) led to the present studies of foot vein compliance in CFS patients with a linear variable differential transformer.

METHODS: Seven patients with CFS were compared with 7 age- and gender matched healthy control subjects in their blood pressure, heart-rate, and plasma norepinephrine responses to prolonged standing and in measurements of their foot vein contractile responses to intravenous norepinephrine infusions with the linear variable differential transformer.

RESULTS: Excessive, delayed (usually after 10 min) orthostatic reductions in systolic and diastolic blood pressure (P < 0.01) and inconsistently excessive increases in heart rate were found in the CFS patients, in whom venous compliance in response to infused norepinephrine was significantly reduced (P < 0.05).

CONCLUSIONS: In these patients with CFS, delayed orthostatic hypotension was clearly demonstrable, and, as in previously reported patients with orthostatic hypotension of acute onset, this was associated with reduced pedal vein compliance during norepinephrine infusion, implying impaired sympathetic innervation of foot veins. The rapid symptomatic improvement demonstrated in previous studies of CFS patients during correction of orthostatic venous pooling by inflation of military antishock trousers (MAST) to 35 mm Hg may suggest that excessive lower body venous pooling, perhaps by reducing cerebral perfusion, is involved in the orthostatic component of fatigue in these patients.

 

Source: Streeten DH. Role of impaired lower-limb venous innervation in the pathogenesis of the chronic fatigue syndrome. Am J Med Sci. 2001 Mar;321(3):163-7. http://www.ncbi.nlm.nih.gov/pubmed/11269790