Individuals with Chiari malformation can present with symptoms of fatigue, lightheadedness, and syncope-the cardinal features of orthostatic intolerance. Similar orthostatic symptoms can complicate the clinical course following Chiari decompression. The presence of orthostatic intolerance in patients with Chiari malformation is not surprising given the location of the major circulatory control centers and their pathways in the brainstem. This article reviews the normal physiologic response to upright posture and the common forms of orthostatic intolerance encountered in clinical practice. The authors describe the relationship between orthostatic intolerance and Chiari malformation and provide suggestions regarding the evaluation and management of these disorders.

Postural Orthostatic Tachycardia Syndrome (POTS) is a chronic health condition affecting mostly women of childbearing age, and significantly impacting their health and quality of life. It is currently poorly understood with no approved licensed treatments. The aim of this systematic review was to contextualize the symptom burden of POTS, and review factors associated with this burden that may guide future treatments. The specific questions were (1) How does symptom burden in POTS compare to the burden in other long term conditions (LTCs), (2) Which factors are associated with POTS symptom burden, and (3) Which interventions show promise in reducing symptom burden in POTS. Electronic databases (CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science, APA PsycArticles, OpenGrey) were searched from inception to January 2022 for observational studies reporting on the association between any biological, psychological or social factors and symptom burden, and randomized controlled trials reporting on interventions for symptom burden in adults with POTS. Two reviewers independently conducted eligibility screening, data extraction and quality assessment. A narrative synthesis was undertaken. 5159 entries were screened for eligibility. Twenty-nine studies were included (1372 participants with POTS of a total sample size of 2314, 17 High-, 12 Medium-quality), seventeen were observational and twelve were randomized controlled experimental and intervention trials. Overall methodological quality of the evidence was medium-high but heterogeneity was high and sample sizes modest, allowing moderately robust conclusions. Orthostatic symptom burden was higher in POTS than other LTCs. Serum activity against adrenergic α1 receptors, physical functioning, depression, catastrophizing, prolonged cognitive stress testing and anxiety were significantly associated with symptom burden in medium-high quality studies. Preliminary medium-high quality evidence from predominantly proof-of-concept (n = 11) studies and one 3-month 2 × 2 factorial design trial suggest that compression garments, propranolol, pyridostigmine, desmopressin, and bisoprolol may hold promise in reducing symptom burden. Directions for future research include investigating associated factors over time, the development of complex interventions which address both biological and psychosocial factors associated with symptom burden, and effectiveness trials of these interventions. POTS symptom burden is high, particularly in relation to orthostatic intolerance when compared to other long-term conditions (LTCs). Despite this burden, there are no effectiveness randomized controlled trials of treatment to reduce symptoms in POTS. This review provides a starting point to understanding researched biological and psychosocial factors associated with this burden. There was however inconsistency in the measurement of symptom burden, lowering the confidence of cross-study inferences. A coherent definition of POTS symptom range, severity and impact along with a validated and reliable POTS-specific instrument is currently lacking. A standardized questionnaire to assess POTS symptom burden as a core outcome measure will help clarify future research and clinical practice.

The use of dynamic elastomeric fabric orthoses is examined in a young woman with hypermobile Ehlers-Danlos syndrome (hEDS) referred for physiotherapy with hip dysplasia, prior to a right periacetabular osteotomy. Dynamic elastomeric fabric orthoses plus rigorous subjective examination, therapists' listening skills, and patient-centered goals were useful for this hEDS patient.

[This corrects the article DOI: 10.3389/fnins.2022.968725.].

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.

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

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.

Orthostatic intolerance (OI) is usually mediated by the autonomic nerve and most often happens in the upright position. However, it can also occur in other positions and can be relieved by lying down while likely to have another attack after relief. In the current study, we aim to evaluate the predictive effect of catecholamines and electrolytes on the recurrence of OI in children. Children who were diagnosed with vasovagal syncope (VVS), postural tachycardia syndrome (POTS), and VVS combined with POTS were enrolled in this retrospective study and were followed up after 1-year physical treatment. Catecholamines in urine collected within 24 h, renin, angiotensin II, aldosterone in plasma, and electrolytes in both blood and urine collected in the morning were tested. A multivariate analysis and a receiver operating characteristic curve were used to validate the prediction effect. In the VVS cohort, the 24 h urine adrenaline (AD) and norepinephrine (NE) levels of the non-recurrence group were lower than the 24 h urine AD and NE levels of the recurrence group, with a significant difference of  < 0.05. A different content can also be witnessed in the POTS cohort that the urine of the non-recurrence group contained lower sodium and chlorine. As for the VVS + POTS cohort, the non-recurrence group has lower AD and NE levels and higher potassium and phosphorus levels in urine, the difference of which proved prominent as well. The study provides further evidence that AD, NE, and electrolytes in urine are promising factors that are closely related to the recurrence of OI in children. The integrated evaluation system merging AD and NE may have better predictive ability.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex, chronic, multi-system disorder that is characterized by a substantial impairment in the activities that were well tolerated before the illness. In an earlier report, we had described three adult women who met criteria for ME/CFS and orthostatic intolerance, and had congenital or acquired cervical spinal stenosis. All three experienced substantial global improvements in their ME/CFS and orthostatic intolerance symptoms after recognition and surgical treatment of the cervical stenosis. After a several year period of improvement, one of the individuals in that series experienced a return of ME/CFS and orthostatic intolerance symptoms. Radiologic investigation confirmed a recurrence of the ventral compression of the spinal cord due to a shift of the disc replacement implant at the involved cervical spinal level. Decompression of the spinal cord with removal of the implant and fusion at the original C5-C6 level was once again followed by a similar degree of improvement in function as had been observed after the first operation. This recapitulation of the outcomes after surgical management of cervical stenosis provides further evidence in support of the hypothesis that cervical spinal stenosis can exacerbate pre-existing or cause new orthostatic intolerance and ME/CFS. Especially for those with refractory symptoms and neurological signs, surgical interventions may offer relief for selected patients with this complex condition.

(1) Objective: We performed a systematic review to explore the prevalence of intravenous (IV) rehydration therapy in hospital settings, and we assessed it by patient groups and populations. (2) Methods: A systematic review of major databases and grey literature was undertaken from inception to 28 March 2022. Studies reporting prevalence of IV rehydration therapy in a hospital setting were identified. The data were synthesised in a narrative approach. (3) Results: Overall, 29 papers met the inclusion criteria. The prevalence of IV rehydration therapy in paediatric patients ranged from 4.5% (hospitalised with diarrhoea and dehydration) to 100% (admitted to the emergency department with mild to moderate dehydration caused by viral gastroenteritis), and in adults this ranged from 1.5% (had single substance ingestion of modafinil) to 100% (hospitalised with hypercalcemia). The most common indication for IV rehydration therapy in paediatric patients was dehydration due to fluid loss from the gastrointestinal tract. Other causes included malnutrition, neuromuscular disease, bronchiolitis, and influenza. In adults, indications for IV rehydration therapy were much more diverse: fever, diarrhoea, drug intoxication, hypercalcemia, cancer, and postural tachycardia syndrome; (4) Conclusions: This systematic review showed that IV rehydration therapy in paediatric patients is often used to treat dehydration and diarrhoea, while in adults it has a broader spectrum of use. While IV rehydration therapy is important in correcting fluid problems and electrolyte status, the maintenance fluid prescribing practices vary considerably, and guidelines are scarce.

The novel SARS-CoV-2 virus and resulting COVID-19 global pandemic emerged in 2019 and continues into 2022. While mortality from COVID-19 is slowly declining, a subset of patients have developed chronic, debilitating symptoms following complete recovery from acute infection with COVID-19. Termed as post-acute sequelae of SARS-CoV-2 syndrome (PASC), the underlying pathophysiology of PASC is still not well understood. Given the similarity between the clinical phenotypes of PASC and postural orthostatic tachycardia syndrome (POTS), it has been postulated that dysautonomia may play a role in the pathophysiology of PASC. However, there have been only a few studies that have examined autonomic function in PASC. In this retrospective study, we performed an analysis of autonomic nerve function testing in PASC patients and compared the results with those of POTS patients and healthy controls. Our results suggest that a significant number of PASC patients have abnormal autonomic function tests, and their clinical features are indistinguishable from POTS.

Patients with long QT syndrome (LQTS) face potential threats from COVID-19 vaccination. Fever is one of the issues that is not uncommon after vaccination, and it usually takes place within 2 days. In particular, patients with type 2 LQTS based on trafficking-deficient variants are probably vulnerable to arrhythmogenicity under febrile conditions. Furthermore, myocarditis is one of the rare complications that is possibly associated with acquired QT prolongation and puts patients with LQTS at risk of life-threatening arrhythmia. Moreover, postural orthostatic tachycardia syndrome is another rare condition that, perhaps, poses LQTS patients susceptible to life-threatening arrhythmia when QT interval does not shorten optimally during tachycardia. In this review, we recommended prudent measurements to beneficially reduce the risk for patients with LQTS when vaccination or booster doses are eligible.

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

Patients with post-acute sequelae of COVID-19 (PASC) often experience the addition of new symptoms after recovery from COVID-19 illness. These may include orthostatic intolerance and autonomic dysfunction, and postural orthostatic tachycardia syndrome has been described to occur in a proportion of patients with PASC. In this report, we present a 32-year-old pregnant woman (G3P2) who experiences severe orthostatic symptoms as part of her PASC syndrome, which is decoupled from normal physiologic changes of pregnancy. At 25 weeks of gestation, she was evaluated for increasing episodes of dyspnoea, marked tachycardia with minimal exertion, intermittent non-exertional chest pain, and presyncope. This patient had a moderate course of COVID-19 at 12 weeks of gestation, for which she received monoclonal antibody therapy (casirivimab/imdevimab). The patient then had complete resolution of COVID-19 symptoms and felt well for 1 month prior to developing orthostatic symptoms at 25 weeks of gestation. Evaluation with a NASA Lean Test revealed marked orthostatic tachycardia, as well as delayed orthostatic hypotension. Given her COVID-19 illness 4 months prior, PASC involving autonomic dysfunction was diagnosed. Patients with orthostatic symptoms in PASC should be carefully evaluated with dedicated active stand tests, such as the NASA Lean Test, to characterize the autonomic response to standing. In pregnant patients, an understanding of normal pregnancy physiology is crucial to correctly identify abnormal findings in such tests.

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.

Postural Orthostatic Tachycardia Syndrome (POTS) is a variant of autonomic cardiovascular disorder characterized by an excessive increase in heart rate upon standing associated with light-headedness, headaches, chest pain, shortness of breath, and brain fog. The etiology of POTS is largely unknown and often debilitating. The 3 major hypotheses about the pathophysiology of POTS are autoimmunity, abnormally increased sympathetic activity, and sympathetic denervation leading to central hypovolemia and reflex tachycardia. Given its heterogeneous nature, it is crucial to understand each component of POTS with more emphasis on incorporating a multidisciplinary approach to control the symptoms. Future works should focus on better understanding the POTS pathophysiology and designing randomized controlled trials for implementing effective therapy. In this review, we outline the extent of the problem, studies and resources needed to address the issue, and the diagnostic and therapeutic updates on POTS.

The autonomic nervous system (ANS) is a complex network where sympathetic and parasympathetic domains interact inside and outside of the network. Correlation-based network analysis (NA) is a novel approach enabling the quantification of these interactions. The aim of this study is to assess the applicability of NA to assess relationships between autonomic, sensory, respiratory, cerebrovascular, and inflammatory markers on post-acute sequela of COVID-19 (PASC) and postural tachycardia syndrome (POTS). In this retrospective study, datasets from PASC (n = 15), POTS (n = 15), and matched controls (n = 11) were analyzed. Networks were constructed from surveys (autonomic and sensory), autonomic tests (deep breathing, Valsalva maneuver, tilt, and sudomotor test) results using heart rate, blood pressure, cerebral blood flow velocity (CBFv), capnography, skin biopsies for assessment of small fiber neuropathy (SFN), and various inflammatory markers. Networks were characterized by clusters and centrality metrics. Standard analysis showed widespread abnormalities including reduced orthostatic CBFv in 100%/88% (PASC/POTS), SFN 77%/88%, mild-to-moderate dysautonomia 100%/100%, hypocapnia 87%/100%, and elevated inflammatory markers. NA showed different signatures for both disorders with centrality metrics of vascular and inflammatory variables playing prominent roles in differentiating PASC from POTS. NA is suitable for a relationship analysis between autonomic and nonautonomic components. Our preliminary analyses indicate that NA can expand the value of autonomic testing and provide new insight into the functioning of the ANS and related systems in complex disease processes such as PASC and POTS.

Despite its increasing recognition and extensive research, there is no unifying hypothesis on the pathophysiology of the postural tachycardia syndrome. In this cross-sectional study, we examined the role of fear conditioning and its association with tachycardia and cerebral hypoperfusion on standing in 28 patients with postural tachycardia syndrome (31 ± 12 years old, 25 females) and 21 matched controls. We found that patients had higher somatic vigilance (P = 0.0167) and more anxiety (P < 0.0001). They also had a more pronounced anticipatory tachycardia right before assuming the upright position in a tilt-table test (P = 0.015), a physiological indicator of fear conditioning to orthostasis. While standing, patients had faster heart rate (P < 0.001), higher plasma catecholamine levels (P = 0.020), lower end-tidal CO2 (P = 0.005) and reduced middle cerebral artery blood flow velocity (P = 0.002). Multi-linear logistic regression modelling showed that both epinephrine secretion and excessive somatic vigilance predicted the magnitude of the tachycardia and the hyperventilation. These findings suggest that the postural tachycardia syndrome is a functional disorder in which standing may acquire a frightful quality, so that even when experienced alone it may elicit a fearful conditioned response. Heightened somatic anxiety is associated with and may predispose to a fear-conditioned hyperadrenergic state when standing. Our results have therapeutic implications.

Postural orthostatic tachycardia syndrome (POTS) is a cardiovascular autonomic disorder characterized by excessive heart rate increase on standing, leading to debilitating symptoms with limited therapeutic possibilities. Proteomics is a large-scale study of proteins that enables a systematic unbiased view on disease and health, allowing stratification of patients based on their protein background. The aim of the present study was to determine plasma protein biomarkers of POTS and to reveal proteomic pathways differentially regulated in POTS. We performed an age- and sex-matched, case-control study in 130 individuals (case-control ratio 1:1) including POTS and healthy controls. Mean age in POTS was 30 ± 9.8 years (84.6% women) versus controls 31 ± 9.8 years (80.0% women). We analyzed plasma proteins using data-independent acquisition (DIA) mass spectrometry. Pathway analysis of significantly differently expressed proteins was executed using a cutoff log2 fold change set to 1.2 and false discovery rate (p-value) of < 0.05. A total of 393 differential plasma proteins were identified. Label-free quantification of DIA-data identified 30 differentially expressed proteins in POTS compared with healthy controls. Pathway analysis identified the strongest network interactions particularly for proteins involved in thrombogenicity and enhanced platelet activity, but also inflammation, cardiac contractility and hypertrophy, and increased adrenergic activity. Our observations generated by the first use a label-free unbiased quantification reveal the proteomic footprint of POTS in terms of a hypercoagulable state, proinflammatory state, enhanced cardiac contractility and hypertrophy, skeletal muscle expression, and adrenergic activity. These findings support the hypothesis that POTS may be an autoimmune, inflammatory and hyperadrenergic disorder.

We investigated head-up tilt test (HUTT) results across age-groups in syncope/presyncope patients to establish pediatric postural orthostatic tachycardia syndrome (POTS) characteristics. We retrospectively reviewed syncope patients' medical records. Adolescents were defined as 10 to 19 years old, adults as 20 to 59 years old, and older individuals as ≥60 years old. From HUTT results, we determined POTS prevalence and differences among the age-groups. We included 147 adolescents, 269 adults, and 123 older patients. Seventy (13.0%) patients (61.4% females; median age: 20 [17-25] years) were diagnosed with POTS. The syndrome was more prevalent among adolescents (33 [22.4%]) than adults (37 [13.8%]), and was absent among older individuals. Affected adolescents had significantly lower resting diastolic blood pressure (DBP) and heart rate (HR), and converted to maximum HR more rapidly than adolescents without the syndrome during the passive phase. Adolescents with POTS demonstrated several unique characteristics compared to adults with and adolescents without this syndrome. POTS may be underrecognized among syncope and presyncope patients, among which 22.4% of adolescents were diagnosed with the syndrome. POTS should be considered when evaluating syncope patients.

SARS-CoV-2 is responsible for the global COVID-19 pandemic, with little prevention or treatment options. More than 600 million mortalities have been documented from SARS-CoV-2 infection, with the majority of fatalities occurring among elderly patients (aged >65 years). A number of vaccines have been developed in an effort to restrain the rapid spread of SARS-CoV-2. Considering the widespread administration of these vaccines, substantial side or undesired effects in multiple organ systems have emerged, necessitating essential critical care. Herein, we tabulate the adverse cardiovascular responses resulting from COVID-19 vaccines. We searched PubMed for articles published through April, 2022, with the terms "SARS-CoV-2", "COVID-19", "cardiovascular", "SARS-CoV-2 vaccines", "COVID-19 vaccines", "myocarditis", "pericarditis", "thrombosis", "thrombocytopenia", "vaccine-induced thrombotic thrombocytopenia", "acute coronary syndrome", "myocardial infarction", "hypertension", "arrythmia", "postural orthostatic tachycardia syndrome", "Takotsubo cardiomyopathy", "cardiac arrest" and "death". We mainly selected publications from the past 3 years, but did not exclude widely referenced and highly regarded older publications. Besides, we searched the reference lists of articles identified by above search method and chose those we considered relevant. COVID-19 vaccines evoke rare but fatal thrombotic events, whereas messenger RNA\055based vaccines appear to be associated with risks of pericarditis/myocarditis, with the latter being more predominant in young adults following the second dose. Reports of other cardiovascular responses, including hypertension, arrhythmia, acute coronary syndrome, and cardiac arrest, have also been indicated. The undesired cardiovascular complications remain infrequent, giveng the large number of vaccinations inoculated to general population. And lower mortality takes precedence over the undesired cardiovascular complications.

Signal detection yields confirmed signals in only 2.1%, which imposes a heavy burden on the pharmacovigilance system in the European Union. We aimed to develop a network theoretical metric to increase the confirmed signal ratio of individual case safety report (ICSR) networks. ICSRs of five cardiovascular adverse events were requested from EudraVigilance. We developed Vigilace™, a web-based application to build network representation of ICSRs. Three network-based signal scores, which we termed NEWS (normalized edge weight for signals) scores, were calculated by normalizing the weight of each edge in the report-based weighted network by the weight of the same edge in topological weighted networks. Depending on the third node in topological network edges, we defined full-, adverse event-, and drug-type NEWS scores. Area under the receiver operating characteristic curves (AUROC) were analyzed to compare the reporting odds ratio (ROR) and NEWS scores. Overall, 72,475 ICSRs were accessed from EudraVigilance. Drug-type NEWS (NEWS) score performed better (DeLong test, p-value <0.05) compared with the ROR in case of four adverse events: acute myocardial infarction (AUROC: 0.856 vs. 0.720), arrhythmia (0.657 vs. 0.614), pulmonary hypertension (0.861 vs. 0.720), and QT prolongation (0.830 vs. 0.749). Postural orthostatic tachycardia syndrome was excluded due to the lack of reference data. This is the first demonstration that report-based weighting normalized by topological weighting of co-reported drugs, which we termed as NEWS score, can perform better compared with the ROR. An application was developed for ICSR network analysis that facilitates the calculation of this score.

No formal diagnostic criteria exist for the neuropathic subtype of postural orthostatic tachycardia syndrome (POTS). Skin biopsy and quantitative sudomotor axon reflex testing (QSORT) are preferred methods of assessment for autonomic small fiber neuropathy (SFN). This study characterizes the utility of these testing methods at a tertiary center and identifies clinical features associated with abnormal testing. Medical records of 2658 patients undergoing tilt table testing at a single institution between June 2018 and December 2020 were reviewed. Patients with postural orthostatic tachycardia syndrome were included for analysis of intraepidermal nerve fiber density (IENFD), sweat output, comorbidities, symptoms, measures of cardiovascular autonomic function, and serum antibody levels. 356 patients (90% female, mean age 31 ± 10) met the diagnostic criteria for postural orthostatic tachycardia syndrome. Of 211 patients who underwent quantitative sudomotor axon reflex testing, 70 (33%) demonstrated reduced sweat output. These patients were more likely to demonstrate sympathetic impairment during the Valsalva maneuver. Of 80 patients who underwent skin biopsies, 19 (24%) demonstrated reduced intraepidermal nerve fiber density. These patients tended to be older and have reduced heart rate variability during deep breathing. Neither test was associated with specific serum antibodies, symptoms, or comorbidities, though there was a trend toward higher rates of comorbid autoimmune disease in patients with abnormal testing. A subset of patients with postural orthostatic tachycardia syndrome have evidence of small fiber neuropathy. These patients tend to have impaired cardiovascular autonomic function but are otherwise similar to patients with no evidence of small fiber neuropathy.

The worldwide spread of the coronavirus disease 2019 (COVID-19) pandemic and the significant morbidity and mortality rate associated with it led to the rapid development of several COVID-19 vaccines. While serious side effects related to the vaccines are rare, various adverse events have been reported to occur after COVID-19 messenger RNA (mRNA) vaccination, including myocarditis, Guillain-Barré syndrome, and thrombosis. Postural orthostatic tachycardia syndrome (POTS) is a chronic cardiovascular dysautonomia among young and middle-aged individuals. Although the pathophysiology of POTS is thought to be heterogeneous, vaccine-induced immune-mediated autonomic dysfunction is hypothesized to be one cause of the syndrome. In this report, we present a case of myocarditis and POTS occurring in a 13-year-old male following COVID-19 mRNA vaccination. He presented with persistent severe fatigue and headache. The patient's symptoms improved after intravenous immunoglobulin for myocarditis, non-pharmacologic interventions, and multiple medications for POTS.

Postural orthostatic tachycardia syndrome (POTS) is a complex multisystem disorder characterized by orthostatic intolerance and tachycardia and may be triggered by viral infection. Recent reports indicate that 2%-14% of coronavirus disease 2019 (COVID-19) survivors develop POTS and 9%-61% experience POTS-like symptoms, such as tachycardia, orthostatic intolerance, fatigue, and cognitive impairment within 6-8 months of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Pathophysiological mechanisms of post-COVID-19 POTS are not well understood. Current hypotheses include autoimmunity related to SARS-CoV-2 infection, autonomic dysfunction, direct toxic injury by SARS-CoV-2 to the autonomic nervous system, and invasion of the central nervous system by SARS-CoV-2. Practitioners should actively assess POTS in patients with post-acute COVID-19 syndrome symptoms. Given that the symptoms of post-COVID-19 POTS are predominantly chronic orthostatic tachycardia, lifestyle modifications in combination with the use of heart rate-lowering medications along with other pharmacotherapies should be considered. For example, ivabradine or β-blockers in combination with compression stockings and increasing salt and fluid intake has shown potential. Treatment teams should be multidisciplinary, including physicians of various specialties, nurses, psychologists, and physiotherapists. Additionally, more resources to adequately care for this patient population are urgently needed given the increased demand for autonomic specialists and clinics since the start of the COVID-19 pandemic. Considering our limited understanding of post-COVID-19 POTS, further research on topics such as its natural history, pathophysiological mechanisms, and ideal treatment is warranted. This review evaluates the current literature available on the associations between COVID-19 and POTS, possible mechanisms, patient assessment, treatments, and future directions to improving our understanding of post-COVID-19 POTS.