Canadian Cardiovascular Society Position Statement on Postural Orthostatic Tachycardia Syndrome (POTS) and Related Disorders of Chronic Orthostatic Intolerance

Cardiovascular autonomic dysfunction in post-COVID-19 syndrome: a major health-care burden

Cardiovascular autonomic dysfunction (CVAD) is a malfunction of the cardiovascular system caused by deranged autonomic control of circulatory homeostasis. CVAD is an important component of post-COVID-19 syndrome, also termed long COVID, and might affect one-third of highly symptomatic patients with COVID-19. The effects of CVAD can be seen at both the whole-body level, with impairment of heart rate and blood pressure control, and in specific body regions, typically manifesting as microvascular dysfunction. Many severely affected patients with long COVID meet the diagnostic criteria for two common presentations of CVAD: postural orthostatic tachycardia syndrome and inappropriate sinus tachycardia. CVAD can also manifest as disorders associated with hypotension, such as orthostatic or postprandial hypotension, and recurrent reflex syncope. Advances in research, accelerated by the COVID-19 pandemic, have identified new potential pathophysiological mechanisms, diagnostic methods and therapeutic targets in CVAD. For clinicians who daily see patients with CVAD, knowledge of its symptomatology, detection and appropriate management is more important than ever. In this Review, we define CVAD and its major forms that are encountered in post-COVID-19 syndrome, describe possible CVAD aetiologies, and discuss how CVAD, as a component of post-COVID-19 syndrome, can be diagnosed and managed. Moreover, we outline directions for future research to discover more efficient ways to cope with this prevalent and long-lasting condition.

Exploring the complexities of illness identity and symptom management in seeking a diagnostic label of postural orthostatic tachycardia syndrome (POTS): An inductive approach

OBJECTIVES

Postural orthostatic tachycardia syndrome (POTS) is a debilitating and under-recognized condition of the autonomic nervous system. This study applied Leventhal's Common-Sense Model of Illness Representations to explore the journey to a diagnosis of POTS and to understand its relevance to poorly understood conditions which have common comorbidities.

DESIGN

An inductive qualitative approach was used to explore the processes by which patients formulate explanations and management of symptoms within the search for a diagnostic label and to investigate illness identity in the context of existing diagnoses or multimorbidity.

METHODS

Participants (n = 29) for this nested qualitative study were recruited from a larger longitudinal study of people who had been newly referred to a specialist POTS service. Semi-structured interviews were conducted via video call. Three researchers coded and analysed data using Reflexive Thematic Analysis and elements of Grounded Theory.

RESULTS

The analysis resulted in three overarching themes: 'Seeking physiological coherence and validation', 'Individual persistence', and 'Navigating the cumulative burden'. 'Accessibility and disparities of health care' was noted as a contextual factor. Receiving a POTS diagnosis was regarded by participants as providing legitimacy and increased access to treatment. Overall, delays in the diagnostic journey and the lack of a clear diagnosis impacted negatively on patients through increased uncertainty and a lack of clear guidance on how to manage symptoms. Findings also suggested there were great complexities in assigning symptoms to labels in the context of multimorbidity.

CONCLUSIONS

Participants' stories highlighted the urgent need for better recognition of POTS so that the self-regulatory process can be initiated from the early stages of symptom detection.

The use and effectiveness of exercise for managing postural orthostatic tachycardia syndrome in young adults with joint hypermobility and related conditions: A scoping review

PURPOSE

Postural Orthostatic Tachycardia Syndrome (POTS) is a form of dysautonomia. It may occur in isolation, but frequently co-exists in individuals with hypermobile variants of Ehlers-Danlos Syndrome (EDS) and related conditions (chronic fatigue syndrome [CFS] and fibromyalgia). Exercise is recommended for non-pharmacological POTS management but needs to be individualised. This scoping review explores the current literature on use and effectiveness of exercise-based management for POTS, with specific focus on individuals with joint hypermobility and related conditions who experience hypermobility, and/or pain, and/or fatigue.

METHODS

A systematic search, to January 2023, of Medline, EMBASE, AMED, CINAHL and the Cochrane library was conducted. Studies that reported on adolescents and adults who had been diagnosed with POTS using standard criteria and underwent an exercise-based training intervention were included.

RESULTS

Following full-text screening, 10 articles were identified (2 randomised control trials, 4 comparative studies and 4 case reports). One comparative study reported a small subset of participants with EDS and one case report included an individual diagnosed with CFS; the remainder investigated a wider POTS population. Overall, 3 months of endurance followed by resistance exercise, graduating from the horizontal-to-upright position reduced POTS symptoms and improved quality-of-life.

CONCLUSION

The findings highlight a paucity of higher-level studies documenting exercise for POTS management in people with joint hypermobility and related conditions. Results from the wider POTS population demonstrate exercise is safe and effective. Large, well-designed clinical studies exploring exercise for POTS management adapting to meet the complex musculoskeletal and non-musculoskeletal features of symptomatic joint hypermobility are needed.

Effect of lower body negative pressure on cardiac and cerebral function in postural orthostatic tachycardia syndrome: A pilot MRI assessment

Postural orthostatic tachycardia syndrome (POTS) is characterized by an excessive heart rate (HR) response upon standing and symptoms indicative of inadequate cerebral perfusion. We tested the hypothesis that during lower body negative pressure (LBNP), individuals with POTS would have larger decreases in cardiac and cerebrovascular function measured using magnetic resonance (MR) imaging. Eleven patients with POTS and 10 healthy controls were studied at rest and during 20 min of -25 mmHg LBNP. Biventricular volumes, stroke volume (SV), cardiac output (Qc), and HR were determined by cardiac MR. Cerebral oxygen uptake (VO2 ) in the superior sagittal sinus was calculated from cerebral blood flow (CBF; MR phase contrast), venous O2 saturation (SvO2 ; susceptometry-based oximetry), and arterial O2 saturation (pulse oximeter). Regional cerebral perfusion was determined using arterial spin labelling. HR increased in response to LBNP (p < 0.001) with no group differences (HC: +9 ± 8 bpm; POTS: +13 ± 11 bpm; p = 0.35). Biventricular volumes, SV, and Qc decreased during LBNP (p < 0.001). CBF and SvO2 decreased with LBNP (p = 0.01 and 0.03, respectively) but not cerebral VO2 (effect of LBNP: p = 0.28; HC: -0.2 ± 3.7 mL/min; POTS: +1.1 ± 2.0 mL/min; p = 0.33 between groups). Regional cerebral perfusion decreased during LBNP (p < 0.001) but was not different between groups. These data suggest patients with POTS have preserved cardiac and cerebrovascular function.

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.

[Consenso del grupo de trabajo de los trastornos de la conducta alimentaria de SENPE (GTTCA-SENPE). Evaluación y tratamiento médico-nutricional en la anorexia nerviosa. Actualización 2023]

Anorexia nervosa (AN) is a multifactorial disorder. A possible role of the social network and the gut microbiota in pathogenesis has been added. Exogenous shocks such as the COVID19 pandemic have had a negative impact on patients with AN. The potential medical and nutritional impact of malnutrition and/or compensatory behaviors gives rise to a complex disease with a wide range of severity, the management of which requires a multidisciplinary team with a high level of subject matter expertise. Coordination between levels of care is necessary as well as understanding how to transition the patient from pediatric to adult care is essential. A proper clinical evaluation can detect possible complications, as well as establish the organic risk of the patient. This allows caregivers to tailor the medical-nutritional treatment for each patient. Reestablishing adequate nutritional behaviors is a fundamental pillar of treatment in AN. The design of a personalized nutritional treatment and education program is necessary for this purpose. Depending on the clinical severity, artificial nutrition may be necessary. Although the decision regarding the level of care necessary at diagnosis or during follow-up depends on a number of factors (awareness of the disease, medical stability, complications, suicidal risk, outpatient treatment failure, psychosocial context, etc.), outpatient treatment is the most frequent and most preferred choice. However, more intensive care (total or partial hospitalization) may be necessary in certain cases. In severely malnourished patients, the appearance of refeeding syndrome should be prevented during renourishment. The presence of AN in certain situations (pregnancy, vegetarianism, type 1 diabetes mellitus) requires specific care. Physical activity in these patients must also be addressed correctly.

[Neuropathic pain as a symptom in autonomic neuropathies and other rare diseases : Small fiber neuropathy: its recognition, diagnosis, and treatment]

BACKGROUND

Neuropathic pain is difficult to diagnose and treat. Small fiber neuropathy (SFN) flies under the radar of nerve conduction studies.

OBJECTIVES

The importance of a structured patient history and physical examination in the context of neuropathic pain is emphasized. Describing SFN as an important cause, the authors consider rare but partially treatable differential diagnoses. They conclude that autonomic symptoms are frequently associated, often presenting with diverse symptoms.

METHODS

A selective literature research to present SFN symptoms as well as differential diagnostic and therapeutic steps in the context of SFN and rare diseases focusing on the autonomic nervous system.

RESULTS

Neuropathic pain significantly reduces quality of life. To shorten the time until diagnosis and to initiate therapy, the authors recommend a structured patient history including sensory plus and minus symptoms and non-specific autonomic signs. If the initial search for the cause is not successful, rare causes such as treatable transthyretin (ATTR) amyloidosis and Fabry's disease or autoimmune causes should be considered, particularly in the case of progressive and/or autonomic symptoms.

CONCLUSION

The diagnosis and therapy of rare SFN requires interdisciplinary collaboration and, in many cases, a referral to specialized centers to achieve the best patient care.

Possible Role of Fibrinaloid Microclots in Postural Orthostatic Tachycardia Syndrome (POTS): Focus on Long COVID

Postural orthostatic tachycardia syndrome (POTS) is a common accompaniment of a variety of chronic, inflammatory diseases, including long COVID, as are small, insoluble, 'fibrinaloid' microclots. We here develop the argument, with accompanying evidence, that fibrinaloid microclots, through their ability to block the flow of blood through microcapillaries and thus cause tissue hypoxia, are not simply correlated with but in fact, by preceding it, may be a chief intermediary cause of POTS, in which tachycardia is simply the body's exaggerated 'physiological' response to hypoxia. Similar reasoning accounts for the symptoms bundled under the term 'fatigue'. Amyloids are known to be membrane disruptors, and when their targets are nerve membranes, this can explain neurotoxicity and hence the autonomic nervous system dysfunction that contributes to POTS. Taken together as a system view, we indicate that fibrinaloid microclots can serve to link POTS and fatigue in long COVID in a manner that is at once both mechanistic and explanatory. This has clear implications for the treatment of such diseases.

Postural orthostatic tachycardia syndrome after COVID-19 vaccination

BACKGROUND

There is an association between coronavirus disease 2019 (COVID-19) mRNA vaccination and the incidence or exacerbation of postural orthostatic tachycardia syndrome (POTS).

OBJECTIVE

The purpose of this study was to characterize patients reporting new or exacerbated POTS after receiving the mRNA COVID-19 vaccine.

METHODS

We prospectively collected data from sequential patients in a POTS clinic between July 2021 and June 2022 reporting new or exacerbated POTS symptoms after COVID-19 vaccination. Heart rate variability (HRV) and skin sympathetic nerve activity (SKNA) were compared against those of 24 healthy controls.

RESULTS

Ten patients (6 women and 4 men; age 41.5 ± 7.9 years) met inclusion criteria. Four patients had standing norepinephrine levels > 600 pg/mL. All patients had conditions that could raise POTS risk, including previous COVID-19 infection (N = 4), hypermobile Ehlers-Danlos syndrome (N = 6), mast cell activation syndrome (N = 6), and autoimmune (N = 7), cardiac (N = 7), neurological (N = 6), or gastrointestinal conditions (N = 4). HRV analysis indicated a lower ambulatory root mean square of successive differences (46.19 ±24 ms; P = .042) vs control (72.49 ± 40.8 ms). SKNA showed a reduced mean amplitude (0.97 ± 0.052 μV; P = .011) vs control (1.2 ± 0.31 μV) and burst amplitude (1.67 ± 0.16 μV; P = .018) vs control (4. 3 ± 4.3 μV). After 417.2 ± 131.4 days of follow-up, all patients reported improvement with the usual POTS care, although 2 with COVID-19 reinfection and 1 with small fiber neuropathy did have relapses of POTS symptoms.

CONCLUSION

All patients with postvaccination POTS had pre-existing conditions. There was no evidence of myocardial injuries or echocardiographic abnormalities. The decreased HRV suggests a sympathetic dominant state. Although all patients improved with guideline-directed care, there is a risk of relapse.

Autonomic Manifestations of Long-COVID Syndrome

PURPOSE OF REVIEW

Long-COVID is a novel condition emerging from the COVID-19 pandemic. Long-COVID is characterized by symptoms commonly seen in autonomic disorders including fatigue, brain fog, light-headedness, and palpitations. This article will critically evaluate recent findings and studies on Long-COVID and its physiological autonomic manifestations.

RECENT FINDINGS

Studies have reported on the prevalence of different symptoms and autonomic disorders in Long-COVID cohorts. Autonomic nervous system function, including both the parasympathetic and sympathetic limbs, has been studied using different testing techniques in Long-COVID patients. While numerous mechanisms may contribute to Long-COVID autonomic pathophysiology, it is currently unclear which ones lead to a Long-COVID presentation. To date, studies have not tested treatment options for autonomic disorders in Long-COVID patients. Long-COVID is associated with autonomic abnormalities. There is a high prevalence of clinical autonomic disorders among Long-COVID patients, with limited knowledge of the underlying mechanisms and the effectiveness of treatment options.

Validation of symptom measures in patients under investigation for postural orthostatic tachycardia syndrome (POTS): The Orthostatic Grading Scale (OGS) and the Symptom Screen for Small-fiber Polyneuropathy (SSS)

OBJECTIVES

Postural Orthostatic Tachycardia Syndrome (POTS) presents with a range of poorly delineated symptoms across several domains. There is an urgent need for standardized symptom reporting in POTS, but a lack of validated symptom burden instruments. Our aim was to evaluate the psychometric properties of two symptom burden measures: the Orthostatic Grading Scale (OGS) and the Symptom Screen for Small-Fiber Polyneuropathy (SSS), in patients under investigation for suspected POTS.

DESIGN

Psychometric validation study.

METHODS

Confirmatory factor analysis (CFA) tested the factor structure of the SSS and OGS completed by 149 patients under investigation for POTS. Scale reliability and validity were assessed. The uni-dimensionality of the SSS was assessed through principal component analysis (PCA).

RESULTS

CFA of the OGS revealed that a 1-factor structure had adequate fit. CFA of the SSS revealed that a 5-factor structure had generally appropriate fit supporting the originally proposed 5 factors (1: Gastrointestinal, 2: Somatosensory, 3: Miscellaneous, 4: Microvascular, and 5: Urological). In addition, the SSS demonstrated sufficient uni-dimensionality in the PCA, warranting use of a single total score. Omega coefficients of both measures indicated satisfactory internal reliability (0.668-0.931). Correlations with related constructs (distress (K10 score), r = 0.317-0.404, p < 0.001) and heart rate indices (with the OGS, r = 0.211-0.294, p < 0.05) suggested sound convergent and divergent validity.

CONCLUSIONS

Initial evidence suggests that the OGS and SSS have good psychometric properties for use in populations with suspected and confirmed POTS.

Understanding, diagnosing, and treating Myalgic encephalomyelitis/chronic fatigue syndrome - State of the art: Report of the 2nd international meeting at the Charité Fatigue Center

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a devastating disease affecting millions of people worldwide. Due to the 2019 pandemic of coronavirus disease (COVID-19), we are facing a significant increase of ME/CFS prevalence. On May 11th to 12th, 2023, the second international ME/CFS conference of the Charité Fatigue Center was held in Berlin, Germany, focusing on pathomechanisms, diagnosis, and treatment. During the two-day conference, more than 100 researchers from various research fields met on-site and over 700 attendees participated online to discuss the state of the art and novel findings in this field. Key topics from the conference included: the role of the immune system, dysfunction of endothelial and autonomic nervous system, and viral reactivation. Furthermore, there were presentations on innovative diagnostic measures and assessments for this complex disease, cutting-edge treatment approaches, and clinical studies. Despite the increased public attention due to the COVID-19 pandemic, the subsequent rise of Long COVID-19 cases, and the rise of funding opportunities to unravel the pathomechanisms underlying ME/CFS, this severe disease remains highly underresearched. Future adequately funded research efforts are needed to further explore the disease etiology and to identify diagnostic markers and targeted therapies.

Adrenal gland response to adrenocorticotropic hormone is intact in patients with postural orthostatic tachycardia syndrome

BACKGROUND

Many patients with postural orthostatic tachycardia syndrome (POTS) are hypovolemic with plasma volume deficits of 10-30 %. Some also have low levels of aldosterone and diminished aldosterone-renin ratios despite elevations in angiotensin II, pointing to potential adrenal dysfunction. To assess adrenal gland responsiveness in POTS, we measured circulating levels of aldosterone and cortisol following adrenocorticotropin hormone (ACTH) stimulation.

METHODS

While on a low Na+ diet (∼10 mEq/day), 8 female patients with POTS and 5 female healthy controls (HC) received a low dose (1 μg) ACTH bolus following a baseline blood sample. After 60 min, a high dose (249 μg) infusion of ACTH was administered to ensure maximal adrenal response. Venous aldosterone and cortisol levels were sampled every 30 min for 2 h.

RESULTS

Aldosterone increased in both groups in response to ACTH but was not different between POTS vs. HC at 60 min (53.5 ng/dL [37.8-61.8 ng/dL] vs. 46.1 ng/dL [36.7-84.9 ng/dL]; P = 1.000) or maximally (56.4 ng/dL [49.2-67.1 ng/dL] vs. 49.5 ng/dL [39.1-82.8 ng/dL]; P = 0.524). Cortisol increased in both groups in response to ACTH but was not different in patients with POTS vs. HC at 60 min (39.9 μg/dL [36.1-47.7 μg/dL] vs. 39.3 μg/dL [35.4-46.6 μg/dL]; P = 0.724) or maximally (39.9 μg/dL [33.9-45.4 μg/dL] vs. 42.0 μg/dL [37.6-49.7 μg/dL]; P = 0.354).

CONCLUSIONS

ACTH appropriately increased the aldosterone and cortisol levels in patients with POTS. These findings suggest that the response of the adrenal cortex to hormonal stimulation is intact in patients with POTS.

Postural orthostatic tachycardia syndrome and other related dysautonomic disorders after SARS-CoV-2 infection and after COVID-19 messenger RNA vaccination

The COVID-19 pandemic has caused a challenge for our society due to the post-acute sequelae of the disease. Persistent symptoms and long-term multiorgan complications, known as post-acute COVID-19 syndrome, can occur beyond 4 weeks from the onset of the COVID-19 infection. Postural orthostatic tachycardia syndrome (POTS) is considered a variety of dysautonomia, which is characterized by chronic symptoms that occur with standing and a sustained increase in heart rate, without orthostatic hypotension. POTS can lead to debilitating symptoms, significant disability, and impaired quality of life. In this narrative review, the etiopathogenic basis, epidemiology, clinical manifestations, diagnosis, treatment, prognosis, and socioeconomic impact of POTS, as well as other related dysautonomic disorders, after COVID-19 infection and SARS-CoV-2 postvaccination, were discussed. After a search conducted in March 2023, a total of 89 relevant articles were selected from the PubMed, Google Scholar, and Web of Science databases. The review highlights the importance of recognizing and managing POTS after COVID-19 infection and vaccination, and the approach to autonomic disorders should be known by all specialists in different medical areas. The diagnosis of POTS requires a comprehensive clinical assessment, including a detailed medical history, physical examination, orthostatic vital signs, and autonomic function tests. The treatment of POTS after COVID-19 infection or vaccination is mainly focused on lifestyle modifications, such as increased fluid and salt intake, exercise, and graduated compression stockings. Pharmacotherapy, such as beta-blockers, fludrocortisone, midodrine, and ivabradine, may also be used in selected cases. Further research is needed to understand the underlying mechanisms, risk factors, and optimal treatment strategies for this complication.

Co-creation of a complex, multicomponent rehabilitation intervention and feasibility trial protocol for the PostUraL tachycardia Syndrome Exercise (PULSE) study

BACKGROUND

There is a dearth of research to support the treatment of people with postural tachycardia syndrome (PoTS). Despite expert consensus suggesting exercise is recommended for this patient group, there are no randomised control trials examining this rigorously. The aim was to co-create a feasibility trial protocol and a rehabilitation intervention for people living with PoTS.

METHODS

The intervention and feasibility trial design were co-created as part of the PostUraL tachycardia Syndrome Exercise (PULSE) study. We used the 'three co's framework' of co-define, co-design and co-refine. Recruitment included key national charities and National Health Service Trusts treating people living with PoTS in the UK. Eighteen patient and public involvement members attended the co-define session, and 16 co-creators with a mix of expertise attended the subsequent co-design and co-refine sessions. Seven intervention practitioners were trained in the rehabilitation intervention, providing feedback for further co-refinement.

RESULTS

The final co-created intervention comprises online physical activity, and lifestyle and behaviour change support sessions. It is based on functional movement activities using a patient-centred approach tailored to individual needs. Physical activity intensity is guided by individuals' perception of effort rather than by objective measures. Recumbent bikes are provided for home use. Patients deemed randomisation to be acceptable because research in this area was considered important.

CONCLUSIONS

An innovative approach was used to co-create the PULSE intervention and feasibility trial protocol to meet the evidence-based and logistical needs of people living with PoTS, clinicians, service deliverers, third-sector organisations, academics and funders. This can be used as a successful example and template for future research internationally. People living with PoTS were recognised as experts and involved in every aspect of conceptualisation, design and refinement. This complex rehabilitation intervention is currently being tested in a randomised feasibility trial comparing the PULSE intervention with best-practice usual care for people living with PoTS.

TRIAL REGISTRATION

ISRCTN45323485 was registered on April 7, 2020.

Poor health-related quality of life in postural orthostatic tachycardia syndrome in comparison with a sex- and age-matched normative population

PURPOSE

The effect of postural orthostatic tachycardia syndrome (POTS) on health-related quality of life (HrQoL) remains poorly studied. Here, we sought to compare the HrQoL in individuals with POTS to a normative age-/sex-matched population.

METHODS

Participants enrolled in the Australian POTS registry between 5 August 2021 and 30 June 2022 were compared with propensity-matched local normative population data from the South Australian Health Omnibus Survey. The EQ-5D-5L instrument was used to assess HrQoL across the five domains (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) with global health rating assessed with a visual analog scale (EQ-VAS). A population-based scoring algorithm was applied to the EQ-5D-5L data to calculate utility scores. Hierarchical multiple regression analyses were undertaken to explore predictors of low utility scores.

RESULTS

A total of 404 participants (n = 202 POTS; n = 202 normative population; median age 28 years, 90.6% females) were included. Compared with the normative population, the POTS cohort demonstrated significantly higher burden of impairment across all EQ-5D-5L domains (all P < 0.001), lower median EQ-VAS (p < 0.001), and lower utility scores (p < .001). The lower EQ-VAS and utility scores in the POTS cohort were universal in all age groups. Severity of orthostatic intolerance symptoms, female sex, fatigue scores, and comorbid diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome were independent predictors of reduced HrQoL in POTS. The disutility in those with POTS was lower than many chronic health conditions.

CONCLUSIONS

This is the first study to demonstrate significant impairment across all subdomains of EQ-5D-5L HrQoL in the POTS cohort as compared with a normative population.

TRIAL REGISTRATION

ACTRN12621001034820.

Skin sympathetic nerve activity and nocturnal blood pressure nondipping in patients with postural orthostatic tachycardia syndrome

OBJECTIVE

Postural orthostatic tachycardia syndrome (POTS) is associated with abnormal blood pressure (BP) regulation and increased prevalence of nocturnal nondipping. We hypothesized that nocturnal nondipping of BP is associated with elevated skin sympathetic nerve activity (SKNA) in POTS.

METHOD

We used an ambulatory monitor to record SKNA and electrocardiogram from 79 participants with POTS (36 ± 11 years, 72 women), including 67 with simultaneous 24-h ambulatory BP monitoring.

RESULTS

Nocturnal nondipping of BP was present in 19 of 67 (28%) participants. The nondipping group had a higher average SKNA (aSKNA) from midnight of day 1 to 0100 h on day 2 than the dipping group ( P  = 0.016, P  = 0.030, respectively). The differences (Δ) of aSKNA and mean BP between daytime and night-time were more significant in the dipping group compared with the nondipping group (ΔaSKNA 0.160 ± 0.103 vs. 0.095 ± 0.099 μV, P  = 0.021, and Δmean BP 15.0 ± 5.2 vs. 4.9 ± 4.2 mmHg, P  < 0.001, respectively). There were positive correlations between ΔaSKNA and standing norepinephrine (NE) (r = 0.421, P  = 0.013) and the differences between standing and supine NE levels ( r  = 0.411, P  = 0.016). There were 53 (79%) patients with SBP less than 90 mmHg and 61 patients (91%) with DBP less than 60 mmHg. These hypotensive episodes were associated with aSKNA of 0.936 ± 0.081 and 0.936 ± 0.080 μV, respectively, which were both significantly lower than the nonhypotensive aSKNA (1.034 ± 0.087 μV, P  < 0.001 for both) in the same patient.

CONCLUSION

POTS patients with nocturnal nondipping have elevated nocturnal sympathetic tone and blunted reduction of SKNA between day and night. Hypotensive episodes were associated with reduced aSKNA.

Cognitive functioning in postural orthostatic tachycardia syndrome among different body positions: a prospective pilot study (POTSKog study)

PURPOSE

Approximately 96% of patients with postural orthostatic tachycardia syndrome (PoTS) report cognitive complaints. We investigated whether cognitive function is impaired during sitting and active standing in 30 patients with PoTS compared with 30 healthy controls (HCs) and whether it will improve with the counter manoeuvre of leg crossing.

METHODS

In this prospective pilot study, patients with PoTS were compared to HCs matched for age, sex, and educational level. Baseline data included norepinephrine plasma levels, autonomic testing and baseline cognitive function in a seated position [the Montreal Cognitive Assessment, the Leistungsprüfsystem (LPS) subtests 1 and 2, and the Test of Attentional Performance (TAP)]. Cognitive functioning was examined in a randomized order in supine, upright and upright legs crossed position. The primary outcomes were the cognitive test scores between HCs and patients with PoTS at baseline testing, and among the different body positions.

RESULTS

Patients with PoTS had impaired attention (TAP median reaction time) in the seated position and impaired executive functioning (Stroop) while standing compared with HC. Stroop was influenced by position (supine versus upright versus upright legs crossed) only in the PoTS group. Leg crossing did not result in an improvement in executive function. In patients with PoTS, there was a negative correlation of Stroop with norepinephrine plasma levels while standing.

CONCLUSION

Compared with HCs, PoTS participants showed impaired cognitive attention and executive function in the upright position that did not improve in the legs crossed position. Data provide further evidence for orthostatic cognitive deterioration in patients with PoTS.

TRIAL REGISTRATION INFORMATION

The study was registered at ClinicalTrials.gov (NCT03681080).

Autonomic Dysfunction Related to Postacute SARS-CoV-2 Syndrome

Persistence of symptoms beyond the initial acute phase of coronavirus disease-2019 (COVID-19) is termed postacute SARS-CoV-2 (PASC) and includes neurologic, autonomic, pulmonary, cardiac, psychiatric, gastrointestinal, and functional impairment. PASC autonomic dysfunction can present with dizziness, tachycardia, sweating, headache, syncope, labile blood pressure, exercise intolerance, and "brain fog." A multidisciplinary team can help manage this complex syndrome with nonpharmacologic and pharmacologic interventions.

[S1 guidelines for the management of postviral conditions using the example of post-COVID-19]

These S1 guidelines are an updated and expanded version of the S1 guidelines on long COVID differential diagnostic and management strategies. They summarize the state of knowledge on postviral conditions like long/post COVID at the time of writing. Due to the dynamic nature of knowledge development, they are intended to be "living guidelines". The focus is on practical applicability at the level of primary care, which is understood to be the appropriate place for initial access and for primary care and treatment. The guidelines provide recommendations on the course of treatment, differential diagnostics of the most common symptoms that can result from infections like with SARS-CoV-2, treatment options, patient management and care, reintegration and rehabilitation. The guidelines have been developed through an interdisciplinary and interprofessional process and provide recommendations on interfaces and possibilities for collaboration.

Predicting Therapeutic Efficacy of Pharmacological Treatments in Children with Postural Orthostatic Tachycardia Syndrome: A Mini-Review

Postural orthostatic tachycardia syndrome (POTS) is common in children, with an excessive increment in heart rate when moving from the supine to upright position. It has significant negative impacts on the daily life of pediatric patients. The pathogenesis of POTS includes peripheral vascular dysfunction, central hypovolemia, abnormal autonomic function, a high-adrenergic state, impaired skeletal-muscle pump function, the abnormal release of vasoactive factors, and autoimmune abnormalities. Therefore, the empirical use of pharmacological treatments has limited therapeutic efficacy due to the diversity of its mechanisms. A crucial aspect of managing POTS is the selection of appropriate treatment targeting the specific pathogenesis. This review summarizes the commonly used pharmacological interventions, with a focus on their predictive indicators for treatment response. Factors such as heart rate variability, plasma biomarkers, and cardiac-function parameters are discussed as potential predictors of therapeutic efficacy, enabling the implementation of individualized treatment to improve therapeutic effectiveness. This review consolidates the current knowledge on POTS, encompassing its clinical characteristics, epidemiological patterns, underlying pathogenic mechanisms, and predictive indicators for treatment response. Further research is warranted to enhance the understanding of POTS and facilitate the development of more effective therapeutic approaches for this challenging syndrome.

Cardiovascular Considerations in the Management of People With Suspected Long COVID

Approximately 15% of adult Canadians with SARS-CoV-2 infection develop lingering symptoms beyond 12 weeks after acute infection, known as post-COVID condition or long COVID. Some of the commonly reported long COVID cardiovascular symptoms include fatigue, shortness of breath, chest pain, and palpitations. Suspected long-term cardiovascular complications of SARS-CoV-2 infection might present as a constellation of symptoms that can be challenging for clinicians to diagnose and treat. When assessing patients with these symptoms, clinicians need to keep in mind myalgic encephalomyelitis/chronic fatigue syndrome, postexertional malaise and postexertional symptom exacerbation, dysautonomia with cardiac manifestations such as inappropriate sinus tachycardia, and postural orthostatic tachycardia syndrome, and occasionally mast cell activation syndrome. In this review we summarize the globally evolving evidence around management of cardiac sequelae of long COVID. In addition, we include a Canadian perspective, consisting of a panel of expert opinions from people with lived experience and experienced clinicians across Canada who have been involved in management of long COVID. The objective of this review is to offer some practical guidance to cardiologists and generalist clinicians regarding diagnostic and treatment approaches for adult patients with suspected long COVID who continue to experience unexplained cardiac symptoms.

Objective Hemodynamic Cardiovascular Autonomic Abnormalities in Post-Acute Sequelae of COVID-19

BACKGROUND

Many COVID-19 patients are left with symptoms several months after resolution of the acute illness; this syndrome is known as post-acute sequalae of COVID-19 (PASC). We aimed to determine the prevalence of objective hemodynamic cardiovascular autonomic abnormalities (CAA), explore sex differences, and assess the prevalence of CAA among hospitalized vs nonhospitalized patients with PASC.

METHODS

Patients with PASC (n = 70; female [F] = 56; 42 years of age; 95% confidence interval [CI], 40-48) completed standard autonomic tests, including an active stand test 399 days (338, 455) after their COVID-19 infection. Clinical autonomic abnormalities were evaluated.

RESULTS

Most patients with PASC met the criteria for at least 1 CAA (51; 73%; F = 43). The postural orthostatic tachycardia syndrome hemodynamic (POTSHR) criterion of a heart rate increase of > 30 beats per minute within 5 to 10 minutes of standing was seen in 21 patients (30%; F = 20; P = 0.037 [by sex]). The initial orthostatic hypotension hemodynamic (IOH40) criterion of a transient systolic blood pressure change of > 40 mm Hg in the first 15 seconds of standing was seen in 43 (61%) patients and equally among female and male patients (63% vs 57%; P = 0.7). Only 9 (13%) patients were hospitalized; hospitalized vs nonhospitalized patients had similar frequencies of abnormalities (67% vs 74%; P = 0.7).

CONCLUSIONS

Patients with PASC have evidence of CAA, most commonly IOH40, which will be missed unless an active stand test is used. Female patients have increased frequency of POTSHR, but IOH40 is equally prevalent between sexes. Finally, even nonhospitalized "mild" infections can result in long-term CAAs.

Postural orthostatic tachycardia syndrome-like symptoms following COVID-19 vaccination: An overview of clinical literature

BACKGROUND

Postural Orthostatic Tachycardia Syndrome (POTS) is a common condition affecting more than 170 people per 100,000 population. However, POTS following COVID-19 vaccination remains a rare reporting in the medical literature.

OBJECTIVE

We, herein, summarize and highlight the evidence that has been reported regarding POTS-like symptoms following COVID-19 vaccination.

METHODS

We conducted a literature search and summarized the findings in the form of a narrative commentary. All types of publications (case reports/series, original articles, letters to editors, brief communications etc.) in English language were included.

RESULTS

Whilst the exact pathogenetic mechanism behind POTS is yet to elucidated, there has been increasing evidence pointing towards an autoimmune dysfunction. Females were found to be predominantly affected (72%) with age range from 17 years to 52 years. Additionally, it seems that POTS-like symptoms could be triggered after immunization with Pfizer- BioNTech, Moderna, and Oxford-AstraZeneca COVID-19 vaccines. The symptoms typically appear within the first week, depending upon previous exposure to the virus and presence of other systemic conditions. In some patients, the condition is self-resolving. However, in others, non-pharmacological interventions coupled with negative ionotropic medications can be used for symptomatic management of the patients.

CONCLUSIONS

Timely diagnosis and proper treatment are quintessential for ensuring early alleviation (and in some cases complete resolution) of symptoms. Furthermore, there may be episodes of relapse. Overall prognosis of the new-onset POTS-like symptoms is difficult to predict based on current literature.

Active Stand Testing for Identification of Postural Orthostatic Tachycardia Syndrome

A 67-year-old woman presented to the Emergency Department (ED) of a Level 4 Hospital with a history of "dizziness" on standing. The front-door frailty team, including a consultant geriatrician, reviewed her in the ED. An Active Stand test was performed on the day of attendance, identifying Postural Orthostatic Tachycardia Syndrome (POTS). This was attributed to underlying adrenal insufficiency and managed with oral steroids. "Dizziness" is a common presentation to Emergency Departments and can be challenging to investigate. This case report describes the application of Comprehensive Geriatric Assessment, the novel use of beat-to-beat non-invasive blood pressure monitoring in an Emergency Department setting, and the benefits for an individual patient presenting with a complaint of "dizziness". While the benefits of Comprehensive Geriatric Assessment have previously been described, our case report suggests that Active Stand testing in an ED setting may help clarify this presentation. Further research in this area could prove beneficial to patients.

Unique considerations for the medical care of restrictive eating disorders in children and young adolescents

BACKGROUND

The medical complications of eating disorders are often approached through an age-neutral lens. However, children and young adolescents may have unique medical complications related to the energy needs and timing of growth and development. Providers caring for patients in this vulnerable age range should understand how to identify, approach, and manage these potential age-related complications.

REVIEW

Evidence continues to accumulate that increasingly younger patients are being diagnosed with eating disorders. These children and young adolescents have significant risk for unique and potentially irreversible medical complications. Without early identification and treatment, restrictive eating disorders may negatively impact linear growth, bone development and brain maturation in children and young adolescents. Additionally, due to the energy needs of growth and development, unique considerations exist for the use of acute medical stabilization and the identification of patients at risk for refeeding syndrome with initial nutritional rehabilitation. This review presents an approach to the evaluation and management of children and young adolescents with eating disorders.

CONCLUSION

Children and young adolescents with restrictive eating disorders may have unique medical complications related to the energy needs and timing of linear growth and pubertal development. Significant risk exists for irreversible medical complications of impaired growth, bone, and brain health. Increased awareness of the energy needs for growth and development may improve early recognition, appropriate intervention, and future outcomes for children and young adolescents with restrictive eating disorders.

Symptoms of postural orthostatic tachycardia syndrome in pregnancy: a cross-sectional, community-based survey

OBJECTIVE

To evaluate the relationship between postural orthostatic tachycardia syndrome (POTS) and pregnancy.

DESIGN

Cross-sectional survey.

SETTING

International.

SAMPLE

A total of 8941 female patients with a diagnosis of POTS.

METHODS

Data from the survey were analysed using descriptive measures and stratified for comparisons.

MAIN OUTCOME MEASURES

Symptom course of POTS during pregnancy. Secondary outcomes included pregnancy loss, POTS onset during pregnancy and the impacts of a comorbid diagnosis of Ehlers-Danlos syndrome or an autoimmune disorder on symptoms during pregnancy.

RESULTS

Overall, 40.8% (n = 3652) of participants reported one or more pregnancies. Most participants experienced worsening of symptoms in the first (62.6%) and third (58.9%) trimesters and 3 months after pregnancy (58.7%), and 81.1% experienced worsening symptoms at any point in their pregnancy. Most participants with worsening symptoms in the first trimester also experienced worsening symptoms in the second (61.6%) and third (68.1%) trimesters, but if they improved in the first trimester then this improvement persisted in the second and third trimesters. Of participants who reported that POTS was triggered by a specific event (41.3%), 8.1% reported pregnancy as the trigger for the onset.

CONCLUSIONS

Postural orthostatic tachycardia syndrome symptoms in the first trimester of pregnancy may help predict symptom course throughout the duration of pregnancy. Some individuals may experience an initial onset of POTS during pregnancy. This novel information may guide clinicians in counselling patients with POTS who are planning pregnancy.

Post-COVID-19 Syndrome Comprehensive Assessment: From Clinical Diagnosis to Imaging and Biochemical-Guided Diagnosis and Management

The COVID-19 outbreak was first reported in 2019, causing massive morbidity and mortality. The majority of the COVID-19 patients survived and developed Post-COVID-19 Syndrome (PC19S) of varying severity. Currently, the diagnosis of PC19S is achieved through history and symptomatology that cannot be explained by an alternative diagnosis. However, the heavy reliance on subjective reporting is prone to reporting errors. Besides, there is no unified diagnostic assessment tool to classify the clinical severity of patients. This leads to significant difficulties when managing patients in terms of public resource utilization, clinical progression monitorization and rehabilitation plan formulation. This narrative review aims to review current evidence of diagnosis based on triple assessment: clinical symptomatology, biochemical analysis and imaging evidence. Further assessment tools can be developed based on triple assessment to monitor patient's clinical progression, prognosis and intervals of monitoring. It also highlights the high-risk features of patients for closer and earlier monitoring. Rehabilitation programs and related clinical trials are evaluated; however, most of them focus on cardiorespiratory fitness and psychiatric presentations such as anxiety and depression. Further research is required to establish an objective and comprehensive assessment tool to facilitate clinical management and rehabilitation plans.

Neurological post-acute sequelae of SARS-CoV-2 infection

The novel coronavirus disease 19 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can have two phases: acute (generally 4 weeks after onset) and chronic (>4 weeks after onset). Both phases include a wide variety of signs and symptoms including neurological and psychiatric symptoms. The signs and symptoms that are considered sequelae of COVID-19 are termed post-COVID condition, long COVID-19, and post-acute sequelae of SARS-CoV-2 infection (PASC). PASC symptoms include fatigue, dyspnea, palpitation, dysosmia, subfever, hypertension, alopecia, sleep problems, loss of concentration, amnesia, numbness, pain, gastrointestinal symptoms, depression, and anxiety. Because the specific pathophysiology of PASC has not yet been clarified, there are no definite criteria of the condition, hence the World Health Organization's definition is quite broad. Consequently, it is difficult to correctly diagnose PASC. Approximately 50% of patients may show at least one PASC symptom up to 12 months after COVID-19 infection; however, the exact prevalence of PASC has not been determined. Despite extensive research in progress worldwide, there are currently no clear diagnostic methodologies or treatments for PASC. In this review, we discuss the currently available information on PASC and highlight the neurological sequelae of COVID-19 infection. Furthermore, we provide clinical suggestions for diagnosing and caring for patients with PASC based on our outpatient clinic experience.

Postural Orthostatic Tachycardia Syndrome in COVID-19: A Contemporary Review of Mechanisms, Clinical Course and Management

The long-term implications of COVID-19 have garnered increasing interest in recent months, with Long-COVID impacting over 65 million individuals worldwide. Postural orthostatic tachycardia syndrome (POTS) has emerged as an important component of the Long-COVID umbrella, estimated to affect between 2 and 14% of survivors. POTS remains very challenging to diagnose and manage - this review aims to provide a brief overview of POTS as a whole and goes on to summarize the available literature pertaining to POTS in the setting of COVID-19. We provide a review of available clinical reports, outline proposed pathophysiological mechanisms and end with a brief note on management considerations.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Post-COVID Syndrome: A Common Neuroimmune Ground?

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic disease of unknown etiology, sharing a similar clinical presentation with the increasingly recognized post-COVID syndrome. We performed the first cross-sectional study of ME/CFS in a community population in Russia. Then we described and compared some clinical and pathophysiological characteristics of ME/CFS and post-COVID syndrome as neuroimmune disorders. Of the cohort of 76 individuals who suggested themselves as suffering from ME/CFS, 56 were diagnosed with ME/CFS by clinicians according to ≥1 of the four most commonly used case definitions. Of the cohort of 14 individuals with post-COVID-19 syndrome, 14 met the diagnostic criteria for ME/CFS. The severity of anxiety/depressive symptoms did not correlate with the severity of fatigue either in ME/CFS or in post-COVID ME/CFS. Still, a positive correlation was found between the severity of fatigue and 20 other symptoms of ME/CFS related to the domains of "post-exertional exhaustion", "immune dysfunction", "sleep disturbances", "dysfunction of the autonomic nervous system", "neurological sensory/motor disorders" and "pain syndromes". Immunological abnormalities were identified in 12/12 patients with ME/CFS according to the results of laboratory testing. The prevalence of postural orthostatic tachycardia assessed in the active orthostatic test amounted to 37.5% in ME/CFS and 75.0% in post-COVID ME/CFS (the latter was higher than in healthy controls, p = 0.02). There was a more pronounced increase in heart rate starting from the 6th minute of the test in post-COVID ME/CFS compared with the control group. Assessment of the functional characteristics of microcirculation by laser doppler flowmetry revealed obvious and very similar changes in ME/CFS and post-COVID ME/CFS compared to the healthy controls. The identified laser doppler flowmetry pattern corresponded to the hyperemic form of microcirculation disorders usually observed in acute inflammatory response or in case of systemic vasoconstriction failure.

Apparent Risks of Postural Orthostatic Tachycardia Syndrome Diagnoses After COVID-19 Vaccination and SARS-Cov-2 Infection

Postural orthostatic tachycardia syndrome (POTS) has been previously described after SARS-CoV-2 infection; however, limited data is available on the relation of POTS with COVID-19 vaccination. Here we show in a cohort of 284,592 COVID-19 vaccinated individuals using a sequence-symmetry analysis, that the odds of POTS are higher 90 days after vaccine exposure than 90 days prior to exposure, and that the odds for POTS are higher than referent conventional primary care diagnoses, but lower than the odds of new POTS diagnosis after SARS-CoV-2 infection. Our results identify a possible association between COVID-19 vaccination and incidence of POTS. Notwithstanding the probable low incidence of POTS after COVID-19 vaccination, particularly when compared to SARS-Cov-2 post-infection odds which were five times higher, our results suggest that further studies, are needed to investigate the incidence and etiology of POTS occurring after COVID-19 vaccination.

Sympathetic toggled sinus rate acceleration as a mechanism of sustained sinus tachycardia in chronic orthostatic intolerance syndrome

BACKGROUND

The role of sympathetic nerve activity to maintain sinus rate acceleration remains unclear.

OBJECTIVE

The purpose of this study was to test the hypothesis that sustained (>30 seconds) sinus rate acceleration can be associated with either a sympathetic driven or a sympathetic toggled mechanism.

METHODS

We used a patch monitor to record skin sympathetic nerve activity (SKNA) and electrocardiogram over 24 hours. Study 1 included chronic orthostatic intolerance (OI) (n = 18), atrial fibrillation (n = 7), and asymptomatic normal control (n = 19) groups. Study 2 included 17 participants with chronic OI not treated with ivabradine, pyridostigmine, or β-blockers.

RESULTS

While a majority of sinus rate acceleration was driven by persistent SKNA in study 1, some episodes were toggled on and off by SKNA bursts without persistent SKNA elevation. The sympathetic toggled sinus rate acceleration episodes were found in 7 of 18 participants with chronic OI (39%), 2 of 7 participants with atrial fibrillation (29%), and 6 of 19 normal control participants (32%) (P = .847) and were faster and longer in the chronic OI group than in other groups. In study 2, there were a total of 11 episodes of sinus rate acceleration that persisted for >200 seconds. Among these episodes, 6 (35%) were toggled on and off by SKNA bursts.

CONCLUSION

Sustained sinus rate acceleration (may be toggled on or off) is associated with SKNA bursts in participants with chronic OI, participants with atrial fibrillation, and normal controls. Patients with OI had more frequent and longer episodes than did other groups.

Medical Management of Restrictive Eating Disorders in Adolescents and Young Adults

The medical provider plays an important role in the management of adolescents and young adults (AYAs) with restrictive eating disorders (EDs), including anorexia nervosa (AN), atypical anorexia nervosa, and avoidant/restrictive food intake disorder. The focus of this article is the medical management of AYAs with restrictive EDs, which can be performed by a number of different medical providers, including pediatricians, family physicians, internists, nurse practitioners, and, in some countries, psychiatrists. This position paper clarifies the role of the medical provider in diagnosing and managing restrictive EDs in AYAs and advocates for consistent standardized terminology for clinical and research purposes when describing the degree of malnutrition and differentiating the degree of malnutrition from treatment goal weight. Boys and men with restrictive EDs are frequently underdiagnosed and may have distinct clinical presentations with important implications for medical management. The medical and psychological complications of AYAs with avoidant/restrictive food intake disorder and atypical anorexia nervosa can be just as severe as those with AN. Scientific evidence supports weight restoration as an important early goal of treatment in AN. Most AYAs with restrictive EDs can be treated as outpatients, and family-based therapy is a first-line outpatient psychological treatment for adolescents with AN. Recent research has demonstrated that inpatient refeeding protocols can start with higher caloric content and advance more rapidly than previously recommended.

Baroreflex sensitivity predicts therapeutic effects of metoprolol on pediatric postural orthostatic tachycardia syndrome

Objective

To determine if the baseline baroreflex sensitivity (BRS) could be a useful predictor for the metoprolol therapeutic efficacy on postural orthostatic tachycardia syndrome (POTS) in children.

Methods

In this retrospective case-control study, 54 children suffering from POTS treated with metoprolol were recruited from the pediatric department of Peking University First Hospital. After 2–3 months of metoprolol treatment, all subjects were divided into responders and non-responders based on whether the symptom score (SS) was decreased by over 50% after metoprolol treatment at the follow-up. The baseline demographic parameters and the supine BRS during the head-up tilt test (HUTT) obtained by Finapres Medical System (FMS) were compared between the two groups. The value of BRS to predict the effectiveness of POTS was analyzed by a receiver-operating characteristic (ROC) curve.

Results

The age, sex, height, weight, body mass index (BMI), course of the disease, baseline SS, medication time, metoprolol dose, and follow-up time of the subjects were not statistically different between the responders and non-responders (P > 0.05). The decline in symptom scores (ΔSS) of the responders was more obvious than that of the non-responders (P < 0.01). The supine BRS, BRS at maximum HR, supine heart rate (HR), and maximum HR were different between responders and non-responders (P < 0.01, P = 0.022, P < 0.01, P = 0.047). The binary multivariable analysis showed that baseline supine BRS was significantly associated with the response to metoprolol therapy [OR: 2.079, 95% CI: (1.077, 4.015), P = 0.029]. According to the ROC curve, the area under the curve (AUC) of baseline BRS was 0.912 (95% CI, 0.840–0.984), with a cut-off value of 8.045 ms/mmHg, yielding a sensitivity and specificity of 75.8% and 95.2%, respectively, in predicting the effectiveness of POTS.

Conclusion

The baseline supine BRS level > 8.045 ms/mmHg can predict a good therapeutic response to metoprolol and the results would assist in guiding the individualized β-adrenoceptor blocker use in pediatric patients suffering from POTS.

Sinus Tachycardia: a Multidisciplinary Expert Focused Review

Sinus tachycardia (ST) is ubiquitous, but its presence outside of normal physiological triggers in otherwise healthy individuals remains a commonly encountered phenomenon in medical practice. In many cases, ST can be readily explained by a current medical condition that precipitates an increase in the sinus rate, but ST at rest without physiological triggers may also represent a spectrum of normal. In other cases, ST may not have an easily explainable cause but may represent serious underlying pathology and can be associated with intolerable symptoms. The classification of ST, consideration of possible etiologies, as well as the decisions of when and how to intervene can be difficult. ST can be classified as secondary to a specific, usually treatable, medical condition (eg, pulmonary embolism, anemia, infection, or hyperthyroidism) or be related to several incompletely defined conditions (eg, inappropriate ST, postural tachycardia syndrome, mast cell disorder, or post-COVID syndrome). While cardiologists and cardiac electrophysiologists often evaluate patients with symptoms associated with persistent or paroxysmal ST, an optimal approach remains uncertain. Due to the many possible conditions associated with ST, and an overlap in medical specialists who see these patients, the inclusion of experts in different fields is essential for a more comprehensive understanding. This article is unique in that it was composed by international experts in Neurology, Psychology, Autonomic Medicine, Allergy and Immunology, Exercise Physiology, Pulmonology and Critical Care Medicine, Endocrinology, Cardiology, and Cardiac Electrophysiology in the hope that it will facilitate a more complete understanding and thereby result in the better care of patients with ST.

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

Background

Methods

Results

Conclusion

Detection of G Protein-Coupled Receptor Autoantibodies in Postural Orthostatic Tachycardia Syndrome Using Standard Methodology

BACKGROUND

Postural orthostatic tachycardia syndrome (POTS) is a disorder of orthostatic intolerance that primarily affects women of childbearing age. The underlying pathophysiology of POTS is not fully understood, but it has been suggested that autoimmunity may play a role. The aim of this study was to compare concentrations of autoantibodies to cardiovascular G protein-coupled receptors between patients with POTS and healthy controls.

METHODS

Sera were collected from 116 patients with POTS (91% female; medium age, 29 years) and 81 healthy controls (84% female; medium age, 27 years) from Calgary, Canada, and Malmö, Sweden. Samples were evaluated for autoantibodies to 11 receptors (adrenergic, muscarinic, angiotensin II, and endothelin) using a commercially available enzyme-linked immunosorbent assay.

RESULTS

Autoantibody concentrations against all of the receptors tested were not significantly different between controls and patients with POTS. The majority of patients with POTS (98.3%) and all controls (100%) had α1 adrenergic receptor autoantibody concentrations above the seropositive threshold provided by the manufacturer (7 units/mL). The proportion of patients with POTS versus healthy controls who fell above the diagnostic thresholds was not different for any tested autoantibodies. Receiver operating characteristic curves showed a poor ability to discriminate between patients with POTS and controls.

CONCLUSIONS

Patients with POTS and healthy controls do not differ in their enzyme-linked immunosorbent assay-derived autoantibody concentrations to cardiovascular G protein-coupled receptors. These findings suggest that these tests are not useful for establishing the role of autoimmunity in POTS.

Postural orthostatic tachycardia syndrome and post-acute COVID-19

While the acute illness of COVID-19 was the initial focus of concern, there are increasing reports of patients with chronic symptoms, known as long-COVID. Dysautonomia may be a possible post-acute neurological complication explaining the persistent symptoms observed in long COVID. Postural tachycardia syndrome (POTS), a form of dysautonomia characterized by sustained tachycardia and orthostatic intolerance, has been increasingly reported in patients after SARS-CoV-2 infection. In this context, this review aimed to report and discuss the available literature pertaining to post COVID-19 POTS.

Neurally Mediated Syncope in Children and Adolescents: An Updated Narrative Review

Syncope presents a proportion of up to 25% among children and adolescents and accounts for 0.9% of emergency room visits. Its most frequent aetiology is neurally mediated syncope, which includes vasovagal syncope and orthostatic hypotension. Up to 70% of the paediatric population with reflex syncope is female. There are usually precipitating factors and prodromes. This mini-review will discuss the particularities of the clinical presentation, diagnosis, modified Calgary score, indications and accuracy of the head-up tilt test, classification, and pathophysiology in four sequential phases. Prognostic data and the non-pharmacological and pharmacological approaches will also be reviewed and differences regarding reflex syncope in adults will be discussed.

Faintly tired: a systematic review of fatigue in patients with orthostatic syncope

BACKGROUND

Orthostatic syncope (transient loss of conscious when standing-fainting) is common and negatively impacts quality of life. Many patients with syncope report experiencing fatigue, sometimes with "brain fog", which may further impact their quality of life, but the incidence and severity of fatigue in patients with syncope remain unclear. In this systematic review, we report evidence on the associations between fatigue and conditions of orthostatic syncope.

METHODS

We performed a comprehensive literature search of four academic databases to identify articles that evaluated the association between orthostatic syncope [postural orthostatic tachycardia syndrome (POTS), vasovagal syncope (VVS), orthostatic hypotension (OH)] and fatigue. Studies were independently screened using a multi-stage approach by two researchers to maintain consistency and limit bias.

RESULTS

Our initial search identified 2797 articles, of which 13 met our inclusion criteria (POTS n = 10; VVS n = 1; OH n = 1; VVS and POTS n = 1). Fatigue scores were significantly higher in patients with orthostatic syncope than healthy controls, and were particularly severe in those with POTS. Fatigue associated with orthostatic syncope disorders spanned multiple domains, with each dimension contributing equally to increased fatigue. "Brain fog" was an important symptom of POTS, negatively affecting productivity and cognition. Finally, fatigue was negatively associated with mental health in patients with POTS.

CONCLUSION

In conditions of orthostatic syncope, fatigue is prevalent and debilitating, especially in patients with POTS. The consideration of fatigue in patients with orthostatic disorders is essential to improve diagnosis and management of symptoms, thus improving quality of life for affected individuals.

The Provision of Dental Care to Post COVID-19 Survivors. A Concise Review

Aims

It has been reported that there are a certain percentage of COVID-19 patients who recover but suffer from devastating permanent organ damage or failure. Others suffer from long Covid syndrome, with prolonged symptoms that persist more than 12 weeks. However, there is scarcity of literature regarding the provision of dental treatment for these two groups of patients. This manuscript reviews the impact of multi-system involvement on the provision of dental care to these patients.

Materials and methods

A search of literature was done in PubMed-Medline and Scopus databases to review the available literature on COVID-19 impacts on pulmonary, cardiovascular, haematologic, renal, gastrointestinal, endocrine, and neurologic systems and respective management in dental clinical settings.

Results

The literature search from PubMed-Medline and Scopus databases resulted in 74 salient articles that contributed to the concise review on COVID-19 effects on pulmonary, cardiovascular, haematologic, renal, gastrointestinal, endocrine, and neurologic systems and/or its respective dental management recommendations.

Conclusions

This concise review covers the management of post COVID-19 patients with pulmonary, cardiovascular, haematologic, renal, gastrointestinal, endocrine, or neurologic system complications.