Autonomic Manifestations of Long-COVID Syndrome

Chronic autonomic symptom burden in long-COVID: a follow-up cohort study

PURPOSE

Autonomic dysfunction is a common and often debilitating feature of long-COVID (LC), however, studies evaluating frequency and severity of chronic autonomic dysfunction in LC are limited. We utilized an established online cohort of participants with LC to assess duration and severity of autonomic dysfunction, impact on quality of life, risk factors of autonomic diagnoses including postural tachycardia syndrome (POTS), and efficacy of common treatments.

METHODS

Our international cohort included 526 adults with LC aged 20-65 years who previously completed baseline evaluations of LC symptoms, autonomic symptom burden, and quality of life. Participants repeated survey instruments and completed new instruments assessing risk factors and symptom mitigation strategies. A subset of individuals completed a 10-min active stand test. Multivariable logistic regression identified predictors of autonomic symptom burden and incident autonomic diagnoses including POTS.

RESULTS

A total of 71.9% of participants with LC had a Composite Autonomic Symptom Score-31 (COMPASS-31) score ≥ 20, suggestive of moderate-to-severe autonomic dysfunction. The median symptom duration was 36 [30-40] months, and 37.5% of participants could no longer work or had to drop out of school due to their illness. In addition, 40.5% of individuals with autonomic dysfunction were newly diagnosed with POTS, representing 33% of the total LC cohort. Female sex and joint hypermobility were associated with an increased risk of autonomic dysfunction.

CONCLUSIONS

Evidence of chronic moderate-to-severe autonomic dysfunction was seen in most participants with LC in our cohort and was significantly associated with reduced quality of life and functional disability. POTS was the most common post-COVID autonomic diagnosis.

Potential Correlation Between Hematological Parameters and Palpitation in Outpatients With COVID-19: A Retrospective Study

BACKGROUND

Research on heart injury caused by COVID-19 is limited to large observational and retrospective cohort studies using imaging or pathological data. Reported changes in the levels of myocardial markers in severe diseases have been limited, with few studies on mild infections. The effects of COVID-19 on cardiac function and changes in myocardial marker levels have not yet been reported.

METHODS

We analyzed data from outpatient blood samples collected at Beijing Anzhen Hospital during the 2022 COVID-19 outbreak and used the same periods in 2020 and 2021 as controls, focusing on changes in routine blood tests, coagulation, myocardial markers, and other blood indices in patients with palpitations.

RESULTS

The number of patients with palpitations increased by 4.87-fold during the COVID-19 mass outbreak in 2022. The indices of myocardial damage did not show any symptom-related increases but decreased within the normal range. The proportion of patients with palpitations whose D-dimer and fibrinogen/fibrin degradation product (FDP) values exceeded the reference ranges increased, as did the numbers of neutrophils, monocytes, and platelets. In this retrospective analysis, we found little change in the myocardial markers in patients with mild COVID-19.

CONCLUSIONS

In patients with mild COVID-19, attention should be diverted from detecting myocardial markers to changes in coagulation test results, focusing on the levels of coagulation indices to improve circulation and prevent thrombosis.

Reduced autonomic function in patients with long-COVID-19 syndrome is mediated by cardiorespiratory fitness

BACKGROUND

Long-COVID-19 syndrome (LCS) exhibits neurological problems such as peripheral neuropathy and autonomic nervous system (ANS) dysfunction. Exercise intolerance and, consequently, low cardiorespiratory fitness (CRF) are some of the most common symptoms of LCS. We describe a series of individuals exhibiting LCS symptoms compared to a control group and posit that this condition may be related to the exercise capacity-mediated disruption of the ANS resulting particularly in exercise intolerance.

METHODS

This study included 87 individuals with LCS and 71 control participants without COVID-19 diagnoses. Heart rate variability (HRV) in supine position is commonly measured to diagnose autonomic dysregulation and subsequently analyzed using the Kubios software (Kuopio, Finland). CRF (peak VO2), post-COVID-19 patient-reported symptoms, maximal muscle strength (grip strength, bilateral leg press, leg extension, pectoral press, and back press exercises), and body composition were also measured. Analysis of covariance (ANCOVA) and mediation analysis were employed to assess the associations among LCS, peak VO2, and HRV indicators. Two-sided p < 0.05 was considered as significant.

RESULTS

The HRV parameters-RR interval, RMSSD, SDNN, PNS index, LF, HF, total power, SD1, and SD2-were significantly elevated (p < 0.05) in the control group when compared to the LCS patients. In contrast, the HR, stress index, and SNS index parameters were significantly higher (p < 0.05) in the LCS group. When adjusted for RR intervals, these parameters remained statistically significant (p < 0.05). A partially mediated effect was found between peak VO2 and RMSSD (mediation effect = 24.4%) as well as peak VO2 and SDNN (mediation effect = 25.1%) in the LCS patients.

CONCLUSIONS

These findings contribute new insights on the interplay between CRF and HRV indicators as well as endorse that dysautonomia may be related to the low peak VO2 observed in long COVID-19 patients.

Long COVID Is Not a Functional Neurologic Disorder

Long COVID is a common sequela of SARS-CoV-2 infection. Data from numerous scientific studies indicate that long COVID involves a complex interaction between pathophysiological processes. Long COVID may involve the development of new diagnosable health conditions and exacerbation of pre-existing health conditions. However, despite this rapidly accumulating body of evidence regarding the pathobiology of long COVID, psychogenic and functional interpretations of the illness presentation continue to be endorsed by some healthcare professionals, creating confusion and inappropriate diagnostic and therapeutic pathways for people living with long COVID. The purpose of this perspective is to present a clinical and scientific rationale for why long COVID should not be considered as a functional neurologic disorder. It will begin by discussing the parallel historical development of pathobiological and psychosomatic/sociogenic diagnostic constructs arising from a common root in neurasthenia, which has resulted in the collective understandings of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and functional neurologic disorder (FND), respectively. We will also review the case definition criteria for FND and the distinguishing clinical and neuroimaging findings in FND vs. long COVID. We conclude that considering long COVID as FND is inappropriate based on differentiating pathophysiologic mechanisms and distinguishing clinical findings.

Long-COVID autonomic syndrome in working age and work ability impairment

Long-COVID19 has been recently associated with long-sick leave and unemployment. The autonomic nervous system functioning may be also affected by SARS-CoV-2, leading to a chronic autonomic syndrome. This latter remains widely unrecognized in clinical practice. In the present study, we assessed the occurrence of Long-COVID19 Autonomic Syndrome in a group of active workers as well as the relationships between their autonomic dysfunction and work ability. This prospective observational study was conducted during the 2nd wave of the pandemic in Italy. Forty-five patients (53.6 ± 8.4 years; 32 M) hospitalized for COVID19, were consecutively enrolled at the time of their hospital discharge (T0) and followed-up for 6 months. Autonomic symptoms and work ability were assessed by COMPASS31 and Work Ability Index questionnaires at T0, one (T1), three and six (T6) months after hospital discharge and compared to those retrospectively collected for a period preceding SARS-CoV-2 infection. Clinical examination and standing test were also performed at T1 and T6. One in three working-age people developed a new autonomic syndrome that was still evident 6 months after the acute infection resolution. This was associated with a significant reduction in the work ability. Recognition of Long-COVID19 Autonomic Syndrome may promote early intervention to facilitate return to work and prevent unemployment.

Prevalence of orthostatic intolerance in long covid clinic patients and healthy volunteers: A multicenter study

Orthostatic intolerance (OI), including postural orthostatic tachycardia syndrome (PoTS) and orthostatic hypotension (OH), are often reported in long covid, but published studies are small with inconsistent results. We sought to estimate the prevalence of objective OI in patients attending long covid clinics and healthy volunteers and associations with OI symptoms and comorbidities. Participants with a diagnosis of long covid were recruited from eight UK long covid clinics, and healthy volunteers from general population. All undertook standardized National Aeronautics and Space Administration Lean Test (NLT). Participants' history of typical OI symptoms (e.g., dizziness, palpitations) before and during the NLT were recorded. Two hundred seventy-seven long covid patients and 50 frequency-matched healthy volunteers were tested. Healthy volunteers had no history of OI symptoms or symptoms during NLT or PoTS, 10% had asymptomatic OH. One hundred thirty (47%) long covid patients had previous history of OI symptoms and 144 (52%) developed symptoms during the NLT. Forty-one (15%) had an abnormal NLT, 20 (7%) met criteria for PoTS, and 21 (8%) had OH. Of patients with an abnormal NLT, 45% had no prior symptoms of OI. Relaxing the diagnostic thresholds for PoTS from two consecutive abnormal readings to one abnormal reading during the NLT, resulted in 11% of long covid participants (an additional 4%) meeting criteria for PoTS, but not in healthy volunteers. More than half of long covid patients experienced OI symptoms during NLT and more than one in 10 patients met the criteria for either PoTS or OH, half of whom did not report previous typical OI symptoms. We therefore recommend all patients attending long covid clinics are offered an NLT and appropriate management commenced.