To support general neurologists, advanced practice providers, and general practitioners in the diagnosis and treatment of postural tachycardia syndrome (POTS) and related dysautonomias. This review and approach are based on the authors' clinical experience, nonsystematic literature review, and expert opinion, with experts drawn from the American Autonomic Society Education Committee. POTS is a common condition seen in general practice. The diagnosis can be easily made in a nonspecialist setting when patients meet the syndromic criteria for POTS: (1) chronic orthostatic intolerance (bothersome symptoms brought on by upright posture, and relieved by lying down), (2) excessive orthostatic tachycardia (heart rate augmentation with standing greater than 30 beats per minute in adults), (3) absence of orthostatic hypotension, and (4) reasonable exclusion of other causes (e.g., dehydration, anemia, hyperthyroidism). There are many causes, but the unifying perturbations are low effective circulating volume with decreased cerebral blood flow and a hypersympathetic state. Education and nonpharmacologic therapies such as salt, water, and exercise are first-line treatments. Several safe and effective medication options are also available, such as propranolol and midodrine. Several comorbidities are common, such as migraine and neurocardiogenic syncope, and should be screened for and treated rather than attributed out-of-hand to POTS. POTS and related conditions are common. Initial diagnostic and treatment steps can be undertaken in a general practice setting. Referral to specialists is appropriate for refractory cases or when the diagnosis is uncertain.

Postural orthostatic tachycardia syndrome (POTS) is a form of dysautonomia characterized by an excessive increase in heart rate upon standing, in the absence of orthostatic hypotension. Post-infectious forms, particularly following SARS-CoV-2 infection, have been increasingly reported. We report the case of a 34-year-old woman presenting with persistent palpitations, marked fatigue, and orthostatic intolerance that developed two weeks after a mild COVID-19 infection. Standard cardiological evaluation revealed no abnormalities. Comprehensive autonomic testing demonstrated an increase in heart rate from 72 to 109 beats per minute at the 11th minute of active standing (Δ +37 bpm), without significant blood pressure drop, confirming the diagnosis of POTS. Additional autonomic assessment identified a hyperadrenergic phenotype. After two months of treatment with ivabradine (5mg daily), heart rate in the standing position stabilized between 80 and 100 beats per minute, with partial clinical improvement. This case highlights the importance of comprehensive autonomic evaluation in post-COVID forms of POTS and supports the role of targeted therapy.

This report is an assessment of the characteristics associated with cardiovascular dysautonomia (CVD) in the context of long Coronavirus disease (COVID), which is currently inadequately characterized. A retrospective cross-sectional study was performed involving 106 patients with long COVID, including 34 individuals diagnosed with CVD, among whom eight met the criteria for Postural Tachycardia Syndrome (PoTS). The variables assessed encompassed individual characteristics (e.g., age, sex, comorbidities), immunization parameters (e.g., vaccination/viral status, timing, frequency), cellular and humoral anti-Spike and anti-Nucleocapsid (Nuc) immune responses, inflammatory and allergic biomarkers, as well as an extensive panel of common autoantibodies comprising anti-nuclear antibodies, anti-central nervous system antibodies (cerebellum, brain), and anti-peripheral nervous system antibodies (gangliosides). An age < 45 years, body mass index, hyperventilation syndrome as well as a higher cumulative number of antigenic contacts (vaccinations plus infections ≥ 3) and an elevated basophil count (≥0.06 G/L) were independently associated with CVD. There was no association between CVD and inflammatory markers or common autoantibodies. Patients with PoTS criteria had a strong anti-Spike cellular immune response and increased IgG anti-Nuc humoral immunity when compared with CVD and non-CVD long COVID counterparts. Compared to other long COVID patients, patients with long COVID-associated CVD have distinctive clinical and immunovirological features. Our results suggest the potential role of the immune response against Spike and of allergic pathways rather than humoral autoimmunity against common autoantibodies in long COVID CVD.

Tilt table testing is commonly used to evaluate orthostatic intolerance and syncope and is typically performed with three-lead electrocardiography (ECG) monitoring, which limits P-wave interpretation. A 21-year-old woman with congenitally corrected transposition of the great arteries presented with recurrent tachy-palpitations and near syncope and was presumed to have postural tachycardia syndrome (POTS) after extensive noninvasive testing. During head-up tilt table testing incorporating intermittent 12-lead ECGs, she developed a sustained narrow-complex tachycardia that reproduced her symptoms. Careful P-wave analysis demonstrated P-wave morphologies that localized the rhythm to a left atrial focus, which was later confirmed on an electrophysiology study. This case highlights the diagnostic value of 12-lead ECGs during tilt table testing for the analysis of P-wave morphology and axis. Ectopic atrial tachycardia may mimic orthostatic syndromes and remain undetected with limited-lead testing. Incorporation of 12-lead ECGs during tilt table testing enables ECG-based localization of atrial arrhythmias, preventing misdiagnosis of orthostatic syndromes.

Postural orthostatic tachycardia syndrome (POTS) is associated with multiple autonomic symptoms, including gastrointestinal (GI) complaints, and has been linked to insulin resistance. We aimed to explore HbA1c, circulating metabolic hormones (insulin, C-peptide, GIP, GLP-1, glucagon, leptin, and peptide YY) and cortisol, and their associations with hemodynamic parameters and GI symptoms in POTS. Two POTS cohorts were studied and compared with matched controls. In the fasting cohort, blood samples were drawn in 42 patients and 41 controls, followed by active standing tests with measurement of pulse and blood pressure (BP) in supine and standing positions. In the non-fasting cohort, questionnaires assessed GI symptoms and HbA1c was measured in 43 patients and 52 controls. Fasting C-peptide and insulin levels correlated with BP in POTS (q = 0.002) but not in controls. Fasting insulin tended to be higher in POTS but was not statistically significant after adjustment for BMI (β = 6.85; 95% CI: -1.04-14.74; p = 0.085). Morning cortisol was comparable between groups. In the non-fasting cohort, HbA1c and metabolic hormones were comparable between groups, with no associations with GI symptoms. Together, these findings suggest a potential link between insulin-related pathways and BP regulation in POTS. Future studies are warranted to further investigate insulin dynamics in POTS.

Cardiac arrhythmias remain a major cause of morbidity and mortality, and current therapies have notable limitations. Vagus nerve stimulation (VNS), which modulates autonomic tone, has emerged as a potential adjunctive treatment. This systematic review evaluated the efficacy of invasive and noninvasive VNS in patients with atrial fibrillation, heart failure, myocardial infarction, and other rhythm disorders. A search of PubMed, Scopus, and Web of Science identified 21 randomized controlled trials, including 11,368 patients. Overall, VNS was associated with reduced atrial fibrillation incidence and burden, improved autonomic function and left ventricular ejection fraction in heart failure, and reduced arrhythmic events and infarct biomarkers after myocardial infarction. Additional benefits were observed in conditions such as vagally mediated atrioventricular block and postural orthostatic tachycardia syndrome. Across studies, VNS demonstrated a favorable safety profile. These findings suggest that VNS may be a promising multimodal strategy for reducing arrhythmia burden and improving cardiac autonomic regulation, although larger confirmatory trials are needed.

Postural orthostatic tachycardia syndrome (POTS) is characterized by an excessive orthostatic heart rate increase and lacks approved pharmacologic therapies. The objective of the study was to compare hemodynamic effects of ivabradine and propranolol and assess medication preferences in patients with POTS. In a randomized, placebo-controlled, crossover trial, patients with POTS completed three 4-week treatment phases (ivabradine, propranolol, and placebo). Each phase concluded with a 10-minute head-up tilt test with continuous beat-to-beat hemodynamic monitoring. Analyses included 28 participants (mean age 33 ± 9 years, 100% female). The prespecified primary outcome was delta heart rate during tilt. Head-up tilt test hemodynamics were described as minute-by-minute averages, deltas from supine baseline, and peak heart rate (HR) in the last 5 to 10 minutes. Prespecified within-participant comparisons were performed between treatments. Treatment preference was recorded at each phase end. Compared to placebo, HR was lower for ivabradine (99 ± 3 vs 118 ± 3 beats/min; P < 0.001) and propranolol (100 ± 3 vs 118 ± 3 beats/min; P < 0.001). ΔHR (standing - supine) was lower for ivabradine (27 ± 2 vs 36 ± 2 beats/min; P = 0.001) and propranolol (28 ± 2 vs 36 ± 2 beats/min; P = 0.003) vs placebo. Ivabradine showed a greater increase in Δ systolic blood pressure compared to propranolol (4.9 mm Hg vs 1.9 mm Hg; P = 0.001) but no significant difference in either HR or ΔHR between them. Among 22 preferences, all participants preferred ivabradine (P < 0.001) or propranolol (P < 0.001) over placebo, without differences between active treatments (59% vs 41%; P = 0.52). Ivabradine and propranolol reduce orthostatic tachycardia vs placebo, lowering heart rate below POTS diagnostic criteria. Ivabradine elevates systolic blood pressuremore than propranolol, supporting personalized drug selection. Importantly, heart rate lowering was consistent whereas symptom and quality-of-life effects were more selective, supporting individualized treatment.

This review summarizes current knowledge on autonomic cardiovascular function, with a focus on sympathetic neural control, in human females across the lifespan in health and disease. Specifically, sympathetic activity at rest and during stressors, sympathetic transduction into vascular resistance or blood pressure, and baroreflex sensitivity under physiological conditions (e.g., the menstrual cycle, oral contraceptives, pregnancy, and menopause) are reviewed. Furthermore, how sympathetic neural control is influenced by pathological conditions that only affect females (e.g., polycystic ovarian syndrome and hypertensive disorders of pregnancy) or that affect a large proportion of females (e.g., postural orthostatic tachycardia syndrome, hypertension, and heart failure with preserved ejection fraction) are also reviewed. Generally, augmented sympathetic activity, blunted sympathetic transduction, and reduced baroreflex sensitivity are associated with disease state. Pregnancy might be the only healthy state that is linked with sympathetic activation. Despite advancements in knowledge over the past 30 years, significant research gaps persist in neural control in females, especially around perimenopause.

Orthostatic intolerance is a category of disorders characterized by inadequate hemodynamic compensation upon standing. In this study, we developed a portable, active abdominal compression binder intended for individuals with orthostatic intolerance. We present proof-of-concept evidence in healthy volunteers demonstrating the binder's ability to provide consistent abdominal compression, reduce tachycardic response upon standing, and maintain user comfort. We designed and fabricated a novel active binder that applies motor-driven abdominal compression upon the detection of standing. Twenty healthy volunteers (ages 18-50 years) completed three randomized supine-to-standing trials: no binder, a commercial passive binder, and the novel active binder. Throughout each trial, compression pressure, heart rate, and respiration were continuously monitored and comfort was assessed via post-trial Likert-scale survey. The active binder achieved a higher mean compression pressure (≈ 11 mmHg) with significantly lower intersubject variability (standard deviation (SD) ≈ 1 mmHg) than the passive binder (mean ≈ 8 mmHg; SD ≈ 3 mmHg). Active compression reduced the standing heart rate by 4.4 bpm compared to control (p < 0.05) vs. a 1 bpm reduction with the passive binder (p > 0.05). Neither the active nor the passive abdominal binders impeded respiration. Survey responses demonstrated that the active binder was at least as comfortable as the passive and was rated easier to don. These findings suggest that active abdominal compression may serve as a more efficacious, consistent, and user-friendly alternative to passive binders for mitigating orthostatic intolerance.

Bowel and skin biopsies from patients with gastrointestinal disorders have revealed neuropathic changes and altered connective tissue. Patients with postural orthostatic tachycardia syndrome (POTS) often suffer from gastrointestinal symptoms and concomitant hypermobility spectrum disorders, such as hypermobile Ehlers-Danlos syndrome (hEDS). Since the skin is more accessible than the bowel, the aim of the present study was to evaluate skin biopsies in a 3D manner using micro-CT in patients with POTS and controls and relate the findings to symptoms presented. Healthy controls (n=13) and patients with POTS with (n=11) or without hEDS/EDS (n=26) were evaluated. Skin biopsies were taken proximally to the lateral malleolus using a 3 mm needle, fixed in formaldehyde and embedded in paraffin. The samples were harvested using a 1.5 mm punch (length, 2-5 mm) and scanned using a laboratory X-ray phase-contrast micro-CT. Scans were evaluated in a blinded manner and the regularity, thickness and tightness of collagen fiber bundles were assessed. All dermal structures were visible without staining. Intraepidermal nerves were not visible and a number of cell types could not be separated. The percentage of disorganized collagen bundles differed between groups, due to the majority being disorganized in hEDS/EDS (P=0.030). The proportion of any disorganized and parallel bundles throughout the biopsy differed within both patient groups (P<0.001) but not within the control group (P=0.175). There were no differences in symptoms between participants with disorganized bundles and participants without disorganized bundles. In conclusion, X-ray phase-contrast micro-CT was suitable to visualize and characterize dermal skin components in 3D. Patients with POTS and hEDS/EDS exhibited more disorganized collagen bundles; however, the technique cannot currently be used for diagnostic purposes until more patients are examined.

What is the clinical question being addressed? What are the clinical and hemodynamic differences between postural orthostatic tachycardia syndrome and inappropriate sinus tachycardia? What is the main finding? Inappropriate sinus tachycardia exhibits higher rates of hypertension, whereas postural orthostatic tachycardia syndrome and dual pathology exhibit higher rates of presyncope, cognitive impairment, and nausea.

Mast cell activation syndrome (MCAS) is a challenging specialized condition that allergists-immunologists treat in the outpatient setting. Despite the wide prevalence of the disease, clinicians may feel overwhelmed to provide consistent compassionate care for these patients for a multitude of reasons. Patients uniformly describe feeling unheard during a clinical encounter and thereby often end up seeing multiple physicians and specialists which further complicates their medical care. As such, it is important to characterize patients with MCAS accurately, which includes the assessment of coexistent mimicking or confounding conditions to achieve best medical care outcomes.

Postural orthostatic tachycardia syndrome (POTS) is a chronic autonomic disorder associated with debilitating symptoms. No medications have been approved for treatment, and patients commonly use off-label medications to treat symptoms. The hemodynamic implications of certain medication use have been examined, but patient experiences with taking off-label medications are underreported. A qualitative descriptive study was conducted with 13 patients (all women; aged 38 ± 13 years) diagnosed with POTS who had taken off-label medications for their symptoms. Semistructured video interviews were conducted to explore how they experienced and perceived their medication use. Interviews were recorded, transcribed, and analyzed using conventional content analysis. Most patients described medications as being beneficial and life-altering, re-enabling basic activities, work, exercise, and social engagement. All patients intended to continue therapy. Side effects were common but generally manageable. Propranolol frequently was associated with fatigue and hypotension. Ivabradine often caused transient early headaches and visual symptoms that subsided. Dosing frequency was largely acceptable. Major barriers included the following: medication cost, especially for ivabradine when patients were not insured; limited clinician awareness of POTS; diagnostic delays; and uncertainty about long-term safety. Medications provide meaningful functional improvement for many patients, but treatment burden, financial barriers, and information gaps persist. Care should prioritize individualized, patient-centred prescribing, and shared decision-making. Additional research should compare common medications to increase exposure and evaluate long-term outcomes and access.

One of the most common complaints in ENT clinics is dizziness. Although most cases are caused by vestibular neuritis and benign paroxysmal positional vertigo (BPPV), a significant number of patients experience non-vestibular dizziness. One non-vestibular cause is postural orthostatic tachycardia syndrome (POTS), which presents with symptoms similar to vestibular migraine (VM) and persistent postural perceptual dizziness (PPPD). Dizziness from POTS is related to dysautonomia rather than the vestibular system. In otolaryngology, understanding the autonomic nature of non-vestibular dizziness is important for accurate diagnosis. This study aims to review the clinical characteristics and pathophysiology of POTS, vestibular migraine, and PPPD; examine historical, physical, and diagnostic findings that differentiate autonomic and vestibular causes of dizziness; and develop a more specific model for evaluating chronic dizziness in the ENT setting. Literature on dizziness, vestibular and autonomic pathophysiology, and the clinical presentation of POTS, VM, and PPPD is reviewed in this paper. The timing of symptoms, their triggers, and objective assessment are key differentiating factors for these disorders. Various diagnostic tools, including orthostatic vital signs, oculomotor assessment, gait and balance evaluation, vestibular function assessment, tilt table testing, and neuroimaging, are also reviewed. Clear distinctions among POTS, VM, and PPPD are made. The diagnostic criteria for POTS are orthostatic tachycardia and posture-dependent symptoms that improve when the patient is in a recumbent position, effectively ruling out vestibular involvement in these patients. Vestibular migraine presents with vertigo accompanied by migraine features such as photophobia, phonophobia, or headache, typically triggered by sensory or environmental factors rather than changes in posture. PPPD manifests as chronic non-spinning dizziness and imbalance lasting at least three months, exacerbated by motion, upright posture, and complex visual environments. Orthostatic vital signs and autonomic assessment should be included in the evaluation of patients presenting with dizziness to differentiate between these disorders. Both vestibular and autonomic dysfunction can lead to chronic dizziness. By incorporating autonomic assessments into vestibular evaluations, ENT physicians can apply a more precise diagnostic model for their patients. Identifying dysautonomia-related dizziness, including POTS, helps reduce the misdiagnosis of vestibular disorders. This approach enables physicians to provide more effective interventions for patients with complex dizziness.

: Patients with postural tachycardia syndrome (POTS) commonly experience gastrointestinal (GI) symptoms. We aim to assess the feasibility and preliminary efficacy data for DA-9701, a prokinetic agent targeting 5-hydroxytryptamine 1A, 5-hydroxytryptamine 4, and dopamine D receptors, in patients with POTS. : In a randomized, double-blind, placebo-controlled, single-center crossover trial, patients with POTS were given either 30 mg of DA-9701 or a placebo 3 times daily for eight weeks in a 1:1 ratio. After a 4-week washout, patients received the alternate treatment for another 8 weeks. The primary endpoint focused on assessing the change in GI symptoms (total Nepean Dyspepsia Index-Korean version [NDI-K] symptom score) from baseline over the 8 week-treatment period. Endpoints were assessed in all enrolled and randomized patients (intention-to-treat), and in those who completed the trial (per-protocol analysis). : Between January 2022 and August 2023, 24 patients were randomized (n = 12 per group), with 3 discontinuing after randomization. DA-9701 did not significantly improve primary endpoints for total NDI-K symptom scores in either the intention-to-treat (least-squares means, -13.9 vs. -9.5, = 0.326) or per-protocol analyses (-17.2 vs -12.0, = 0.242). Notably, a trend toward improvement in specific GI symptoms, such as upper abdominal pain, was observed in both intention- to-treat (-0.6 vs 0.7; = 0.066) and per-protocol analyses (-0.9 vs 0.6; = 0.045). No serious adverse events were observed. DA-9701 did not improve GI symptoms in this crossover trial; however, its potential effect on specific GI symptoms merits further investigation.

We report on a 35-year-old gravida 2 para 1 woman with long-COVID postural orthostatic tachycardia syndrome (POTS) who continued all pharmacologic therapies from preconception through delivery, including ivabradine, a medication contraindicated in pregnancy because of preclinical embryotoxicity and teratogenicity. Serial fetal assessments including growth studies, fetal Dopplers, and nonstress tests remained normal throughout gestation without evidence of fetal bradycardia, arrhythmia, or structural abnormalities. Delivery at 38 weeks 5 days’ gestation resulted in a healthy female neonate. This case illustrates successful use of off-label ivabradine in pregnancy with reassuring maternal–fetal outcomes under close obstetric-cardiology supervision.

BACKGROUND: Pediatric syncope accounts for 1–3% of emergency department (ED) visits. Although most cases are benign, 4% are caused by cardiac disease and 3% by seizures, which carry a risk of sudden death or neurologic injury if missed. Vasovagal syncope accounts for 52–74% of cases and postural orthostatic tachycardia syndrome (POTS) for approximately 13%. OBJECTIVE: To provide an emergency-department risk-stratified diagnostic and disposition framework for pediatric syncope. KEY FINDINGS: A universal 12-lead electrocardiogram (ECG) identifies nearly all life-threatening cardiac causes of syncope. When combined with structured red-flag screening and clinical risk stratification, patients can be reliably divided into low-, intermediate-, and high-risk groups, allowing safe discharge of benign cases and rapid admission of dangerous ones. CONCLUSION: A standardized ED syncope pathway based on risk tiers and ECG-first evaluation improves patient safety while reducing unnecessary admissions and testing. CLINICAL TRIAL NUMBER: Not applicable.

This study evaluated the cerebrospinal fluid (CSF) proteomes from 31 patients diagnosed with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). We quantified 902 proteins, each expressed in at least eleven samples, and systematically categorized clinical factors relevant to ME/CFS symptoms-including autonomic dysfunction, neuroinflammation and metabolic disturbances. Differentially expressed protein and pathway analyses evaluated protein features associated with both postural orthostatic tachycardia syndrome (POTS) status and disease severity among the patients, while ratio-based analysis further explored associations with severity ratings. Data are available via ProteomeXchange with identifier PXD076216. Neutrophil degranulation and platelet activation were enriched in patients with POTS, and several pathways, such as the complement cascade, coagulation-related pathways and IGFBP‑mediated insulin-like growth factor transport, were enriched in severe cases. Ratio-based analysis identified four biologically interpretable severity-associated protein ratios related to cellular stress, extracellular remodelling and immune-neuronal interaction. Together, these findings provide insight into the biological processes associated with clinical heterogeneity in ME/CFS and generate hypotheses for future validation in larger independent cohorts.

Ehlers-Danlos syndrome (EDS) comprises inherited connective tissue disorders characterised by joint hypermobility, skin hyperextensibility and tissue fragility. It links to systemic comorbidities, including gastrointestinal (GI) disorders, but hitherto large-scale data remain limited. We aimed to evaluate the prevalence of GI, systemic and psychological comorbidities in EDS patients versus propensity score-matched controls, using a comprehensive research network database. This was a retrospective, propensity-matched analysis (2005-2023) utilising the TriNetX network. We identified EDS patients (excluding Marfan's syndrome). Propensity score matching (1:1) generated balanced cohorts for age, sex and baseline characteristics. Comorbidities were analysed via prevalence rates and odds ratios (ORs) with 95% confidence intervals (CIs). Matched cohorts included 59,128 pairs. Among GI disorders, gastroesophageal reflux disease was most common in EDS (18.4%, OR 1.5, 95% CI 1.4-1.5, p < 0.001), followed by constipation (12.4%, OR 1.8, 95% CI 1.7-1.9, p < 0.001), irritable bowel syndrome (7.3%, OR 2.6, 95% CI 2.5-2.8, p < 0.001) and gastroparesis (4.7%, OR 8.2, 95% CI 7.3-9.2, p < 0.001). Psychiatric conditions showed heightened prevalence of anxiety (26.1%, OR 1.8, 95% CI 1.7-1.8, p < 0.001) and depression (18.7%, OR 1.3, 95% CI 1.2-1.3, p < 0.001). Systemic comorbidities included postural orthostatic tachycardia syndrome (13.2%, OR 899.7, 95% CI 483.8-1673.0, p < 0.001), chronic pain (7.9%, OR 7.0, 95% CI 6.4-7.6, p < 0.001), migraines (19.7%, OR 2.5, 95% CI 2.4-2.6, p < 0.001) and fibromyalgia (9.5%, OR 1.7, 95% CI 1.6-1.8, p < 0.001). EDS patients exhibit heightened risk for GI, systemic and psychological comorbidities, highlighting the importance of multidisciplinary approaches for effective management.

Patients with hypermobile Ehlers-Danlos syndrome (hEDS) frequently present with circulatory dysfunction, including postural orthostatic tachycardia syndrome (POTS), and cognitive impairments, leading to substantial disability and limitations in daily functioning. Few studies have examined attention, and concentration and associated conditions in hEDS. In this case-control study, we used a comprehensive cognitive test battery to assess whether cognitive performance is impaired in individuals with hEDS and depends on different body positions. Twenty-nine patients and 29 healthy controls (HC) were enrolled. Baseline cognitive assessments included the Performance Scale of an intelligence test (LPS), Montreal Cognitive Assessment (cognitive deficit screening), and Test of Attentional Performance (TAP). The main cognitive tests for assessing the effects of body position were conducted in randomized conditions (supine, standing, and standing legs-crossed) and included the Stroop test, Corsi block-tapping test, Trail Making Test Part B, and Wechsler Memory Scale-revised. Compared to HC, patients with hEDS had higher intellectual performance (p < .050), but besides relevant comorbid conditions, also significantly impaired attention in the TAP (p < .010) and an impairment of executive function assessed by the Stroop test (p < .010) in the legs-crossed compared to the supine position. Attention in the hEDS group was impaired compared to HC, and executive performance was dependent on body position. Individuals performed worse when standing legs-crossed. Hence, impaired proprioception as present in hEDS may, along with comorbid conditions such as pain, be a contributing factor affecting executive function.

Postural orthostatic tachycardia syndrome (POTS) is a chronic autonomic disorder that predominantly affects female patients of childbearing age. Chest pain is a common and debilitating symptom in POTS, but the nature of the chest pain and the patient experience surrounding it remain poorly understood. A qualitative descriptive design was used. Sixteen patients diagnosed with POTS who were experiencing chest pain were recruited. Semistructured video interviews were conducted that explored the nature and impact of chest pain in daily life. Transcribed interviews were manually analyzed using conventional content analysis. Most patients described their chest pain as sharp and stabbing, often radiating from the left side of the chest to the jaw, back, or arms. Triggers for chest pain included physical exertion, such as walking and using stairs, and high temperatures; few described the pain as unpredictable. Frequency and duration of pain varied widely across patients, with episodes of pain ranging from fleeting to constant. Many shared that chest pain restricted physical activities that they once engaged in with their peers and that their social lives were directly affected, as shortness of breath from talking could trigger chest pain. Many patients also described feelings of isolation and frustration because of both their limited social and physical activities and recognition of a decrease in their overall capabilities. The most common coping strategies to mitigate chest pain were sitting or lying down and breathing strategies. Chest pain in POTS affects multiple dimensions of patients' lives and requires ongoing adaptation and coping.

Postural orthostatic tachycardia syndrome (POTS) and neurocardiogenic syncope (NCS) are frequently observed causes of orthostatic intolerance (OI). Clinical experience reveals patients with overlapping symptoms of both. This observation led to the hypothesis of orthostatic tachycardia hypotensive syndrome (OTHS), a distinct OI variant, combines POTS and NCS features. This study aims to define and characterize it. A retrospective chart review of patients presenting with OI and underwent head up tilt (HUT) between 2014 and 2020. We extracted demographic data, findings during HUT including heart rate (HR), systolic blood pressure (SBP), stroke volume (SV), near infrared spectroscopy (NIRS), syncope, cardiac asystole, and convulsions. We divided the subjects into three groups: POTS, NCS, and OTHS. We included patients with POTS (n = 90), NCS (n = 86), and OTHS (n = 101). POTS patients showed higher HR (baseline, recovery, minimum) vs. OTHS (p = 0.047, < 0.001, < 0.001), while OTHS patients had higher HR (5 min, 10 min, minimum, maximum) vs. NCS (p = 0.047, < 0.001, < 0.001, < 0.001). Minimum SBP was higher in POTS vs. OTHS (p < 0.001), and OTHS patients had higher SV (baseline, recovery, minimum, maximum) vs. POTS (p = 0.006, < 0.001, 0.002, 0.005). Patients with POTS have lower baseline NIRS compared to NCS and OTHS (p =  < 0.032, < 0.011). Asystole was significantly more frequent in the NCS group (n = 24, 27.9%) than in the OTHS group (n = 9, 8.9%), with p < 0.001. OTHS is a form of OI characterized by initial orthostatic tachycardia with increased HR > 30-40 bpm followed by hypotension leading to syncope.

In pediatric postural tachycardia syndrome (POTS), presyncope is important yet undercharacterized. It undermines school participation and daily function, while objective bedside markers remain limited. We aimed to delineate clinically usable predictors by integrating cardiovascular responses and cerebral oxygenation during active standing. We operationalized presyncope as visual darkening and examined three physiological correlates: heart rate change (ΔHR), recovery time, and cerebral oxygenation (ΔOxyHb). We conducted a cross-sectional study of 49 pediatric patients with POTS (median age 14.2 years, 46.9% male). Continuous heart rate, blood pressure, and cerebral oxygenation were recorded during a 10-min active standing test; body mass index, inferior vena cava collapsibility index, and urinary sodium were also obtained. Robust regression identified independent predictors of visual darkening. ΔHR emerged as the strongest predictor of visual darkening (coefficient 0.017, 95% CI 0.005-0.030, p = 0.004), followed by recovery time (coefficient 0.005, 95% CI 0.000-0.010, p = 0.055) and ΔOxyHb (coefficient 0.029, 95% CI  - 0.005 to 0.064, p = 0.098). The final model demonstrated strong discriminative ability (AUC 0.842). Patients reporting visual darkening exhibited significantly higher ΔHR (49 [42-59] vs. 41 [38-46] bpm, p = 0.009), longer recovery time (21 [19-28] vs. 19 [17-22] s, p = 0.041), and greater ΔOxyHb reduction (- 8.7 [ - 10.4 to - 2.4] vs. - 3.5 [- 7.0 to - 2.5] μmol/L, p = 0.039). Heart rate change upon standing is the most significant and clinically accessible predictor of visual darkening in pediatric POTS. The combined assessment of ΔHR, recovery time, and cerebral oxygenation offers a comprehensive evaluation of the risk of visual darkening, enabling personalized management strategies for pediatric patients.