Tag: heart rate variability

Diagnostic value of 24-h ECG recording in Long COVID patients with postural orthostatic tachycardia syndrome

Abstract:

Background: Cardiovascular autonomic dysfunction (CVAD) is a major complication for a large proportion of Long COVID (LC) patients. The main phenotype of CVAD is postural orthostatic tachycardia syndrome (POTS), commonly observed as a sequalae of COVID infection, thus defining a subset of LC patients. POTS is a cardiovascular autonomic disorder characterized by an excessive heart rate (HR) increase and symptoms of orthostatic intolerance when assuming upright posture, occurring predominantly in young and middle-aged women. Since the start of COVID-19 pandemic it has been observed that up to 30% of patients with post-COVID-19 syndrome develop POTS with such symptoms as tachycardia, orthostatic intolerance, fatigue, and cognitive impairment. The heterogeneity of POTS symptoms makes the diagnosis and appropriate management of POTS more difficult and one of the first steps for clinicians is to develop and test relevant diagnostic methods for POTS.
Methods: Patients with persistent symptoms, 3 months after an acute SARS-CoV-2 infection were referred to the multi-disciplinary LC unit at a hospital in Sweden. Consecutive patients seen at this unit from 2021 to 2022 underwent a 24-h ECG recording. LC patients with POTS verified by active standing test and/or head-up tilt testing were prospectively enrolled in the study database and were compared with LC patients without POTS according to 3 specific analyses based on 24-h ECG recording : (1) cardiac autonomic activity expressed by heart rate variability, HRV (SDNN and RMSSD in ms) parameters, (2) awakening HR increase (HR mean 10 min before vs. 30 min after awakening) and (3) HR spikes (number/h if at least over than 30 bpm and at least during 30 s). Control group consisted of healthy subjects from 24-h ECG recordings database (HRV analysis) of a hospital in France. Data were expressed as mean (± standard deviation, SD) and frequencies (%).
Results: A total of 120 LC patients (mean age: 42.7 +/-9.97 y, 88% women) and 100 healthy subjects (mean age: 46.4 +/-10.2 y, 82% women) were included. LC with POTS (42%) was associated with (1) a decrease in most HRV parameters (mean SDNN: 86.8 +/-24.3 vs. 108.7 +/-24.1 ms, p=0.03), and the most reduced components were those related to the parasympathetic tone (mean RMSSD: 34,5 +/-20.4 vs. 45.6 +/-22.1 ms, p=0.04), (2) an abrupt and sustained increase in HR during the first 30 min after awakening (+30%, p<0.05) and (3) a higher number of HR spikes per h (1.4 +/-0.8 vs. 0.8 +/-0.7/h, p<0.001) compared with healthy subjects (HRV) and LC patients without POTS (awakenings and HR peaks) respectively.
Conclusion: A triple analysis of 24-h ECG recordings revealed presence of autonomic dysfunction in LC patients with POTS compared with those without POTS. This novel analysis may be introduced in the clinic for screening and therapy monitoring.

Source: D Hupin and others, Diagnostic value of 24-h ECG recording in Long COVID patients with postural orthostatic tachycardia syndrome, EP Europace, Volume 25, Issue Supplement_1, June 2023, euad122.626, https://doi.org/10.1093/europace/euad122.626 (Full text available as PDF file)

Autonomic Nervous System Affection Due to Post Covid Syndrome

Identification of the Effects of Post Covid Syndrome on the Autonomic Nervous System With Heart Rate Variability

Post-Covid syndrome is defined as symptoms that develop in addition to respiratory symptoms in individuals who have had Covid-19 infection for more than 12 weeks. Symptoms such as fatigue, headache, cognitive impairment, dyspnea, heart palpitations, heat intolerance, digestive system disorders, sleep disorders, dermal problems, orthostatic intolerance come to the fore in individuals with post-Covid syndrome. It has been tried to be revealed in some studies that Covid-19 infection affects the autonomic nervous system (ANS) and the relationship between Post-Covid 19 syndrome and ANS dysfunction.
Heart rate variability (HRV) measurement method can be used to evaluate ANS activity. HRV is a non-invasive method and is a measure of the change in heart rate over a period of time. HRV is a scalar quantity that shows the time between two beats of the heart and defines the oscillations between the R-R intervals. In HRV measurements, time-dependent and frequency-dependent measurement results are obtained and from these measurements, time-dependent RMSSD (square root of the square of the difference of the R-R intervals) and frequency-dependent high-frequency (HF) and low frequency (LF) measurement components are used in relation to the sympathetic nervous system (CNS) and parasympathetic nervous system (PSS). HRV can be measured in short-term (5 minutes) in terms of measurement time.
The aim of this study is to clearly reveal the relationship between Post-Covid 19 syndrome and ANS dysfunction and to provide standardization related to HRV measurement method and sub-parameters.
Source: Ali Veysel Özden, M.D. Bahçeşehir University. Istanbul, Beşiktaş, Turkey, 34000. ICH GCP US Clinical Trials Registry, Clinical Trial NCT05502094 https://ichgcp.net/clinical-trials-registry/NCT05502094

Childhood trauma as a risk factor for a dysfunctional heart rate variability in patients with CFS/ME

Background: Myalgic encephalomyelitis, also called Chronic Fatigue Syndrome or ME/CFS, is a severe and complex multisystemic disease with a heterogenous combination of symptoms. Studies have shown decreased heart rate variability (HRV) in this population. Moreover, there is a growing body of evidence showing high levels of childhood trauma (CHT) among ME/CFS patients. Traumatic experiences in childhood are linked to a decreased HRV. Specially, emotional traumatization impacts HRV. The present study investigates HRV in the context of CHT in a ME/CFS population.

Methods 37 patients diagnosed with ME/CFS participated in this study. Demographic-, clinical data, the degree of disability, and RMSSD parameters of HRV were extracted from patient records. HRV data was gathered over 30 minutes whilst in supine position. CHT was administered using the Childhood Trauma Questionnaire-Short Form. Disability was assessed using the Bell Disability Scale. Multiple regression analyses were conducted using the CHT total scores and emotional abuse and emotional neglect subscales in relation to HRV.

Results Variables / Research Materials Data / Observations Results • Fig.5 HRV in the Monitoring compare the interaction between VNS Sympathic Frequency (LF 0.04-0.15) and Parasympathic Frequency (HF 0.15-0.50) in four stages: Orthostatic Schellong Test, start of the Monitoring in lying down position, Middle section after 15 Minutes and after 30 Minutes. • Box-Plot Data shows the most fluctuation of Sympathic in the middle section. The highest scores and fluctuation which appear of Parasympathic activity is in the beginning of the measurement.

Conclusion • In sum, the results of the study suggest that CHT is more prevalent in ME/CFS populations. However, an effect of childhood trauma on HRV function and disability could not be demonstrated in this sample. The findings indicate that the underlying pathophysiologic mechanism of CHT in ME/CFS are more complex and not expressed in HRV. Future studies should include additional aspects and examine the impact of childhood trauma by looking at other biological systems affected in ME/CFS.

Works Cited • Cohen, J. (1988) Statistical power analysis for the behavioral sciences, New York second edition.

Source: Ziaja, Christof, Young, Susanne, Sadre Chirazi – Stark, Michael.Childhood trauma as a risk factor for a dysfunctional heart rate variability in patients with CFS/ME. 2023/05/24 DOI:10.13140/RG.2.2.17700.65929 https://www.researchgate.net/publication/370987476_Childhood_trauma_as_a_risk_factor_for_a_dysfunctional_heart_rate_variability_in_patients_with_CFSME 

Imbalance of Peripheral Temperature, Sympathovagal, and Cytokine Profile in Long COVID

Simple Summary:

In this study, we looked at how persistent inflammation affects peripheral body temperature and sympathovagal balance in individuals with long COVID. Increased temperature and reduced heart rate variability were directly related to the increase in inflammatory cytokines and reduction in anti-inflammatory cytokines. We identified a possible “molecular signature” for long COVID, characterised by a Th17 inflammatory profile with a reduced anti-inflammatory response, resulting in alterations in homeostatic functions and sympathovagal balance.

Abstract:

A persistent state of inflammation has been reported during the COVID-19 pandemic. This study aimed to assess short-term heart rate variability (HRV), peripheral body temperature, and serum cytokine levels in patients with long COVID. We evaluated 202 patients with long COVID symptoms categorized them according to the duration of their COVID symptoms (≤120 days, n = 81; >120 days, n = 121), in addition to 95 healthy individuals selected as controls.
All HRV variables differed significantly between the control group and patients with long COVID in the ≤120 days group (p < 0.05), and participants in the long COVID ≤120 days group had higher temperatures than those in the long COVID >120 days group in all regions analysed (p < 0.05).
Cytokine analysis showed higher levels of interleukin 17 (IL-17) and interleukin 2 (IL-2), and lower levels of interleukin 4 (IL-4) (p < 0.05). Our results suggest a reduction in parasympathetic activation during long COVID and an increase in body temperature due to possible endothelial damage caused by the maintenance of elevated levels of inflammatory mediators.
Furthermore, high serum levels of IL-17 and IL-2 and low levels of IL-4 appear to constitute a long-term profile of COVID-19 cytokines, and these markers are potential targets for long COVID-treatment and prevention strategies.
Source: Neves PFMd, Quaresma JAS, Queiroz MAF, Silva CC, Maia EV, Oliveira JSdS, Neves CMAd, Mendonça SdS, Falcão ASC, Melo GS, Santos IBF, Sousa JRd, Santos EJMd, Vasconcelos PFdC, Vallinoto ACR, Falcão LFM. Imbalance of Peripheral Temperature, Sympathovagal, and Cytokine Profile in Long COVID. Biology. 2023; 12(5):749. https://doi.org/10.3390/biology12050749 https://www.mdpi.com/2079-7737/12/5/749 (Full text)

Sex differences in post-exercise fatigue and function in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

To assess biobehavioral sex differences in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) utilizing a low burden exercise protocol, 22 females and 15 males with ME/CFS and 14 healthy controls underwent two six-min walk tests.

Fifteen daily assessments were scheduled for fatigue and function ratings and heart monitoring. Six-min walk tests were conducted on days 8 and 9. The ME/CFS group showed high self-report fatigue and impaired physical function, whereas healthy controls did not show fatigue or function abnormalities.

In patients, no significant post-exercise changes were found for heart rate variability (HRV); however, heart rate decreased in ME/CFS males from Day 14 to Day 15 (p = 0.046). Female patients showed increased fatigue (p = 0.006) after the initial walk test, but a downward slope (p = 0.008) in fatigue following the second walk test. Male patients showed a decrease in self-report work limitation in the days after exercise (p = 0.046). The healthy control group evidenced a decrease in HRV after the walk tests from Day 9-14 (p = 0.038).

This pilot study did not confirm hypotheses that females as compared to males would show slower exercise recovery on autonomic or self-report (e.g. fatigue) measures. A more exertion-sensitive test may be required to document prolonged post-exertional abnormalities in ME/CFS.

Trial registration: NCT NCT03331419.

Source: Friedberg F, Adamowicz JL, Bruckenthal P, Milazzo M, Ramjan S, Zhang X, Yang J. Sex differences in post-exercise fatigue and function in myalgic encephalomyelitis/chronic fatigue syndrome. Sci Rep. 2023 Apr 3;13(1):5442. doi: 10.1038/s41598-023-32581-w. PMID: 37012343. https://www.nature.com/articles/s41598-023-32581-w (Full text)

Heart Rate Variability and Salivary Biomarkers Differences between Fibromyalgia and Healthy Participants after an Exercise Fatigue Protocol: An Experimental Study

Abstract:

Previous studies showed that people with Fibromyalgia (FM) suffer from dysautonomia. Dysautonomia consists of persistent autonomic nervous system hyperactivity at rest and hyporeactivity during stressful situations. There is evidence that parameters reflecting the complex interplay between the autonomic nervous system and the cardiovascular system during exercise can provide significant prognostic information. Therefore, this study aimed to investigate the differences between people with FM and healthy controls on heart rate variability (HRV) and salivary parameters (such as flow, protein concentration, enzymatic activities of amylase, catalase and glutathione peroxidase) in two moments: (1) at baseline, and (2) after an exercise fatigue protocol.

A total of 37 participants, twenty-one were people with fibromyalgia and sixteen were healthy controls, participated in this cross-sectional study. HRV and salivary samples were collected before and after an exercise fatigue protocol. The fatigue protocol consisted of 20 repetitions of knee extensions and flexions of the dominant leg at 180 °·s-1 (degrees per second).

Significant differences were found in the HRV (stress index, LF and HF variables) and salivary biomarkers (with a higher concentration of salivary amylase in people with FM compared to healthy controls). Exercise acute effects on HRV showed that people with FM did not significantly react to exercise. However, significant differences between baseline and post-exercise on HRV significantly induce alteration on the HRV of healthy controls. Catalase significantly increased after exercise in healthy controls whereas salivary flow significantly increased in women with FM after an exercise fatigue protocol.

Our study suggests that a higher α-amylase activity and an impaired HRV can be used as possible biomarkers of fibromyalgia, associated with a reduction in salivary flow without changes in HRV and catalase activity after a fatigue exercise protocol. More studies should be carried out in the future to evaluate this hypothesis, in order to find diagnostic biomarkers in fibromyalgia.

Source: Costa AR, Freire A, Parraca JA, Silva V, Tomas-Carus P, Villafaina S. Heart Rate Variability and Salivary Biomarkers Differences between Fibromyalgia and Healthy Participants after an Exercise Fatigue Protocol: An Experimental Study. Diagnostics (Basel). 2022 Sep 14;12(9):2220. doi: 10.3390/diagnostics12092220. PMID: 36140620; PMCID: PMC9497903. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9497903/ (Full text)

Therapeutic Approaches to Dysautonomia in Childhood, with a Special Focus on Long COVID

Abstract:

Background: Dysautonomia seems to be important for the pathophysiology of psychosomatic diseases and, more recently, for long COVID. This concept may explain the clinical symptoms and could help open new therapeutic approaches.
Methods: We compared our data from an analysis of heart rate variability (HRV) in an active standing test in 28 adolescents who had developed an inappropriate sinus tachycardia (IST, n = 13) or postural orthostatic tachycardia syndrome (POTS, n = 15) after contracting COVID-19 disease and/or vaccination with 64 adolescents from our database who developed dysautonomia due to psychosomatic diseases prior to the COVID-19 pandemic. We prove the effects of our treatment: omega-3 fatty acid supplementation (O3-FA, n = 18) in addition to propranolol (low dose, up to 20-20-0 mg, n = 32) or ivabradine 5-5-0 mg (n = 17) on heart rate regulation and heart rate variability (HRV).
Results: The HRV data were not different between the adolescents with SARS-CoV-2-related disorders and the adolescents with dysautonomia prior to the pandemic. The heart rate increases in children with POTS while standing were significantly lower after low-dose propranolol (27.2 ± 17.4 bpm***), ivabradine (23.6 ± 8.12 bpm*), and O-3-FA (25.6 ± 8.4 bpm*). The heart rate in children with IST while lying/standing was significantly lower after propranolol (81.6 ± 10.1 bpm**/101.8 ± 18.8***), ivabradine (84.2 ± 8.4 bpm***/105.4 ± 14.6**), and O-3-FA (88.6 ± 7.9 bpm*/112.1/14.9*).
Conclusions: The HRV data of adolescents with dysautonomia after COVID-19 disease/vaccination are not significantly different from a historical control of adolescents with dysautonomia due to psychosomatic diseases prior to the pandemic. Low-dose propranolol > ivabradine > omega-3 fatty acids significantly decrease elevated heart rates in patients with IST and the heart rate increases in patients with POTS and may be beneficial in these children with dysautonomia.
Source: Buchhorn R. Therapeutic Approaches to Dysautonomia in Childhood, with a Special Focus on Long COVID. Children. 2023; 10(2):316. https://doi.org/10.3390/children10020316 https://www.mdpi.com/2227-9067/10/2/316 (Full text)

Cardiac Autonomic Function in Long COVID-19 Using Heart Rate Variability: An Observational Cross-Sectional Study

Abstract:

Background: Heart rate variability is a non-invasive, measurable, and established autonomic nervous system test. Long-term COVID-19 sequelae are unclear; however, acute symptoms have been studied.

Objectives: To determine autonomic cardiac differences between long COVID-19 patients and healthy controls and evaluate associations among symptoms, comorbidities, and laboratory findings.

Methods: This single-center study included long COVID-19 patients and healthy controls. The heart rate variability (HRV), a quantitative marker of autonomic activity, was monitored for 24 h using an ambulatory electrocardiogram system. HRV indices were compared between case and control groups. Symptom frequency and inflammatory markers were evaluated. A significant statistical level of 5% (p-value 0.05) was adopted.

Results: A total of 47 long COVID-19 patients were compared to 42 healthy controls. Patients averaged 43.8 (SD14.8) years old, and 60.3% were female. In total, 52.5% of patients had moderate illness. Post-exercise dyspnea was most common (71.6%), and 53.2% lacked comorbidities. CNP, D-dimer, and CRP levels were elevated (p-values of 0.0098, 0.0023, and 0.0015, respectively). The control group had greater SDNN24 and SDANNI (OR = 0.98 (0.97 to 0.99; p = 0.01)). Increased low-frequency (LF) indices in COVID-19 patients (OR = 1.002 (1.0001 to 1.004; p = 0.030)) and high-frequency (HF) indices in the control group (OR = 0.987 (0.98 to 0.995; p = 0.001)) were also associated.

Conclusions: Patients with long COVID-19 had lower HF values than healthy individuals. These variations are associated with increased parasympathetic activity, which may be related to long COVID-19 symptoms and inflammatory laboratory findings.

Source: Menezes Junior ADS, Schröder AA, Botelho SM, Resende AL. Cardiac Autonomic Function in Long COVID-19 Using Heart Rate Variability: An Observational Cross-Sectional Study. J Clin Med. 2022 Dec 22;12(1):100. doi: 10.3390/jcm12010100. PMID: 36614901; PMCID: PMC9821736. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9821736/ (Full text)

Post-Acute Effect of SARS-CoV-2 Infection on the Cardiac Autonomic Function

Abstract:

Background: Recent studies reported a long-lasting effect of COVID-19 infection that extends beyond the active disease and disrupts various body systems besides the respiratory system. The current study aims to investigate the post-acute effect of SARS-CoV-2 infection on cardiovascular autonomic activity, reactivity and sensitivity in patients who had the infection at least 3 months before.

Methods: This was a comparative cross-sectional observational study. Fifty-nine subjects were allocated into two groups, controls (n=31), who had no history of positive COVID-19 infection, and the post-COVID patients (n=28) who were recruited 3 to 8 months after testing positive for SARS-CoV-2 by reverse transcription polymerase chain reaction (RT-PCR). Baseline cardiovascular autonomic activity was evaluated through recording of baseline heart rate variability (HRV), autonomic reactivity was determined through standard cardiovascular autonomic reflex tests (CART), and cardiac autonomic sensitivity was assessed through cardiac baroreceptor sensitivity (cBRS).

Results: Higher incidence of orthostatic hypotension was observed in post-COVID patients compared to controls (39.3% and 3.2%, respectively, p <0.001). Additionally, significantly reduced handgrip test, and heart rate response to head-up tilt was illustrated in the post-COVID group (p <0.001). About 85.7% of post-COVID participants had at least one abnormal cardiovascular reflex test (CART) compared to the control group (p <0.001). Although HRV parameters (TP, LF, HF, SDRR, RMSSD, pRR50), and the cBRS were numerically lower in the post-COVID-19 group, this did not reach the level of significance.

Conclusion: The results of the present study are suggestive of altered cardiovascular reactivity in post-acute COVID patients and demand further investigation and longer term follow up.

Impaired Cardiac Autonomic Control in Women With Fibromyalgia Is Independent of Their Physical Fitness

Abstract:

Background/objective: Evidence has suggested abnormal cardiac autonomic responses to exercise in patients with fibromyalgia (FM). However, it is not clear whether the dysautonomia represents a reduced physical fitness rather directly related to FM pathogenesis. Thus, we aimed to verify the cardiac autonomic responses before, during, and after a maximal incremental exercise in women with FM and whether these hypothesized alterations would be dependent with their physical fitness.

Methods: This is a cross-sectional study with 23 FM women and 17 healthy women. The participants performed a maximal incremental cycling test to determine their maximal workload (Wmax) and were further matched by their Wmax (14 FM patients, Wmax: 128.6 ± 16.2 W; and 14 healthy women, Wmax: 131.9 ± 15.9 W). Beat-to-beat heart rate (HR) was continuously monitored to calculate HR variability indexes at rest, chronotropic reserve during exercise, and HR recovery.

Results: Heart rate variability indexes related to vagal modulation were significantly lower in FM patients than in healthy women (p < 0.05). The chronotropic reserve and the HR recovery at 30, 120, 180, 300, and 600 seconds after exercise were all lower in FM patients compared with those of healthy women (p < 0.05). Similar findings were found when analysis was performed using the matched physical fitness subgroup.

Conclusions: The documented cardiac autonomic abnormalities at rest, during, and after exercise in FM patients persist even when physical fitness status is taken in account. Thus, strategies to attenuate the dysautonomia in FM patients must be considered.

Source: Schamne JC, Ressetti JC, Lima-Silva AE, Okuno NM. Impaired Cardiac Autonomic Control in Women With Fibromyalgia Is Independent of Their Physical Fitness. J Clin Rheumatol. 2021 Sep 1;27(6S):S278-S283. doi: 10.1097/RHU.0000000000001518. PMID: 32826659. https://pubmed.ncbi.nlm.nih.gov/32826659/