Postural orthostatic tachycardia syndrome (POTS) and supraventricular tachycardia (SVT) are disease states with distinctive features but overlapping clinical manifestations. Currently, studies on the presence of underlying SVT in patients with POTS are lacking. This retrospective study analyzed 64 patients [mean age: 43 years; 41 (61%) women] who had a POTS diagnosis and were found to have concomitant SVT during rhythm monitoring from September 1, 2013 to September 30, 2019 at our Syncope and Autonomic Disorders Clinic. The outcomes assessed were changes in disease severity, frequency of symptoms, heart rate, and blood pressure between before and after SVT ablation. The most frequent types of SVT noted on the electrophysiologic study were atrioventricular nodal reentrant tachycardia (57.81%), atrial flutter (29.68%), atrioventricular reentrant tachycardia (9.37%), atrial tachycardia (1.56%), and junctional tachycardia (1.56%). After SVT ablation, all 64 patients experienced an improvement in symptoms. Palpitations and lightheadedness experienced the most improvement after the procedure (72% vs. 31%; p < 0.001 and 63% vs. 22%; p < 0.001, respectively). There was a significant improvement in the resting heart rate (81.1 ± 12.8 vs. 75.8 ± 15.6 bpm; p < 0.002), but the orthostatic tachycardia on standing persisted (93.6 ± 16.5 vs. 77.3 ± 19.8 bpm; p = 0.14). Underlying SVT in patients with POTS can be missed easily. A strong suspicion and long-term ambulatory cardiac rhythm monitoring can help in diagnosing the condition.

A growing body of evidence suggests that postural orthostatic tachycardia syndrome (POTS) may be an autoimmune disorder. We have reported in a previous manuscript that 89% of POTS patients ( = 55) had elevations in G-protein-coupled adrenergic A1 receptor autoantibodies and 53% had elevations in muscarinic acetylcholine M4 receptor autoantibodies, as assessed by ELISA. Patients with autoimmune disorders have been reported with a variety of elevated cytokines and cytokines (such as rheumatoid arthritis); thus, we evaluated a limited number of cytokines/chemokines in POTS patients with elevated adrenergic and muscarinic receptor autoantibodies. We utilized the plasma of 34 patients from a previous study; all of the patients (100%) had autoantibodies against the A1 adrenergic receptor and 55.9% (19/34) had autoantibodies against the M4 muscarinic acetylcholine receptor. In particular, the plasma cytokine/chemokine levels were measured as biomarkers of inflammation by Quantibody technology (Raybiotech, Peachtree Corners, GA, USA). We also evaluated the platelet dense granule numbers, as these patients frequently complain of symptoms related to platelet dysfunction. Patients were predominantly young females who displayed a multitude of co-morbidities but generally reported viral-like symptoms preceding episodes of syncope. Eighty five percent (29/34) had platelet storage pool deficiency. Patients had elevations in five of ten cytokine/chemokines biomarkers (IL1β, IL21, TNFα, INFγ, and CD30), whereas two biomarkers had decreased levels (CD40L and RANTES). Our observations demonstrate that POTS patients known to have autoantibodies against the G-protein-coupled adrenergic A1 receptor have abnormal plasma concentrations of inflammatory cytokines.

Postural orthostatic tachycardia syndrome (POTS) is a complex, multifaceted disorder that impairs functional status and quality of life. Current pharmacological treatments are limited. This study investigated the effect of ivabradine (selective blocker of the I channel in the sinoatrial node) on heart rate, quality of life (QOL), and plasma norepinephrine (NE) levels in patients with hyperadrenergic POTS defined by plasma NE >600 pg/ml and abnormal tilt table test. In total, 22 patients with hyperadrenergic POTS as the predominant subtype completed a randomized, double-blinded, placebo-controlled, crossover trial with ivabradine. Patients were randomized to start either ivabradine or placebo for 1 month, and then were crossed over to the other treatment for 1 month. Heart rate, QOL, and plasma NE levels were measured at baseline and at the end of each treatment month. The average age was 33.9 ± 11.7 years, 95.5% were women (n = 21), and 86.4% were White (n = 23). There was a significant reduction in heart rate between placebo and ivabradine (p < 0.001). Patients reported significant improvements in QOL with RAND 36-Item Health Survey 1.0 for physical functioning (p = 0.008) and social functioning (p = 0.021). There was a strong trend in reduction of NE levels upon standing with ivabradine (p = 0.056). Patients did not experience any significant side-effects, such as bradycardia or hypotension, with ivabradine. Ivabradine is safe and effective in significantly improving heart rate and QOL in patients with hyperadrenergic POTS as the predominant subtype.

In postural tachycardia syndrome (POTS), a subtype of orthostatic intolerance, the changes in hemodynamics due to postural changes are poorly understood. We speculated that inappropriate venous return, which may occur in the upright position in patients with school-aged POTS, could be detected by echocardiography. Our prospective study was conducted with 100 POTS patients (45 boys and 55 girls), aged 13.1 ± 1.5 years and 52 age- and sex-matched healthy subjects (control). Echocardiography was performed in the supine and sitting positions. Cardiac parameters [stroke volume index, cardiac index, heart rate, and the maximum inferior vena cava diameter (max IVC)] were evaluated in addition to pulse pressure. Unlike the control subjects, POTS patients demonstrated decreased stroke volume index (P = 0.02) and max IVC (P < 0.01) irrespective of posture. The rates of max IVC change did not differ between control and POTS groups. The enrolled POTS patients were divided into two subgroups [dilatation (n = 57) and contraction (n = 43)] based on whether the change rate of max IVC was less than zero or not. The contraction group showed a significantly higher heart rate than the dilatation group with respect to posture (P = 0.03), indicating the poor response of peripheral vessels in the lower limbs only in the contraction group. In conclusion, echocardiographic assessment detected decreased stroke volume and venous return in POTS. The changes in max IVC in response to postural changes may indicate an underlying pathophysiology in POTS.

Patients with postural orthostatic tachycardia syndrome (POTS) have been shown to exhibit comorbid joint hypermobility manifested as Ehlers-Danlos syndrome (EDS) or hypermobility spectrum disorder (HSD). The prevalence of EDS and HSD in POTS has been demonstrated in smaller studies combining adult and pediatric patients. We examined a large series of pediatric patients to determine their prevalence in children with POTS. Patients 18 years old, or less, at initial evaluation at our clinic were included. POTS was diagnosed based on at least six months of frequent debilitating symptoms of orthostatic intolerance, plus a consistent heart rate increase of at least 40 beats per minute without orthostatic hypotension on standing test. Patients with a Beighton score of at least 5/9 plus other systemic findings suggestive of EDS were further evaluated in Connective Tissue Disorders clinics. There were 362 patients meeting inclusion criteria, of which 82 patients had EDS (22.7%) and 141 patients had HSD (39.0%). Patients with EDS had an earlier median age at symptom onset (12.1 vs. 13.5 years, p=0.004) and longer median symptom duration (2.5 vs. 1.5 years, p=0.0008) compared to patients without hypermobility. Our evaluation of a large series of pediatric patients with POTS revealed that over one-fifth of patients had EDS and over one-third of patients had HSD. The awareness of the prevalence of comorbidities such as hypermobility disorders may help inform providers diagnosing and caring for these patients.

Postural Tachycardia Syndrome (PoTS) is a chronic condition often affecting multiple systems with varied presenting symptoms. Diagnosis is made by demonstrating cardiovascular criteria on standing along with clinical assessment. Cardiopulmonary exercise testing has been used to demonstrate and characterise the physiological response to exercise and the severity of the syndrome. Previous studies on exercise testing in these patients have focussed on cardiovascular changes alone. This series characterises the integrated cardiac and respiratory response to exercise seen with cardiopulmonary exercise testing. Our main findings show that peak oxygen uptake, work done and peak heart rate are significantly reduced from their respective predicted values in PoTS patients. However, despite this, most patients demonstrated a normal exercise capacity. Features of ventilatory inefficiency were also seen which suggest exercise capacity in these patients may be limited more by impaired ventilatory control such as dysfunctional breathing during exercise rather than by cardiovascular issues.

A subgroup of postural orthostatic tachycardia syndrome (POTS) patients may also have features of neurocardiogenic syncope (NCS). Syncope and presyncope are predominant clinical features in this subgroup of patients. Asystole has been reported as the cause of some recurrent syncopal episodes following evaluation with an implantable loop recorder (ILR). We present our experience of pacing in a group of patients with POTS and NCS, which resulted in the complete elimination of syncope. We reviewed the charts of 500 patients at the University of Toledo Medical Center from 2003 to 2013 and identified 40 patients who were eligible for inclusion in this study. Patients were included in this study if they had clinical features of POTS and unusually frequent episodes of syncope. All study participants subsequently underwent ILR implantation. Forty patients, including 32 (80%) women, aged 33 ± 13 years were included in this study. All patients demonstrated prolonged asystole (> 6 seconds) or severe bradycardia (heart rate < 30 bpm) during their syncope. Ten patients demonstrated an asystole of more than 10 seconds and also had prolonged and convulsive syncope. All patients had abrupt syncope without any warning signs. All 40 patients underwent dual-chamber pacemaker implantation. Syncope was eliminated in all 40 patients following pacemaker implantation; however, they continued to experience orthostatic tachycardia. Our findings support that dual-chamber pacing may help to eliminate syncope in a subgroup of POTS patients with recurrent syncope and prolonged asystole on ILR.

The purpose of this study is to evaluate endothelial function in postural tachycardia syndrome (PoTS), a poorly understood chronic condition characterized by a state of consistent orthostatic tachycardia (delta heart rate ≥30 beats per minute) upon standing without orthostatic hypotension. Nineteen patients with PoTS and 9 healthy controls were studied after 3 days of a fixed, caffeine-free, normal sodium (150 milliequivalents/day) diet. All participants underwent autonomic function testing, including sinus arrhythmia, valsalva maneuver, hyperventilation, cold pressor, handgrip, and a standing test with catecholamine measurements, followed by endothelial function testing. We analyzed 3 measures of endothelial function: percent brachial flow-mediated dilation, digital pulsatile arterial tonometry, and postischemic percent leg blood flow. Flow-mediated dilation was significantly lower in patients with PoTS (6.23±3.54% for PoTS) than in healthy controls (10.6±4.37% for controls versus, =0.014). PoTS and controls had similar digital pulsatile arterial tonometry (1.93±0.40 arbitrary units for controls versus 2.13±0.63 arbitrary units for PoTS). PoTS had similar but suggestive percent leg blood flow to controls (313±158% for PoTS versus 468±236% for controls, =0.098). Patients with PoTS have significantly reduced flow-mediated dilation compared with healthy controls, suggesting that PoTS is characterized by endothelial dysfunction in conduit arteries. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01308099.

To describe clinical features, diagnostic findings, treatments, and outcomes in patients with new-onset postural orthostatic tachycardia syndrome (POTS) and other autonomic disorders following SARS-CoV-2 infection (COVID-19). We retrospectively reviewed medical records for patients who presented with persistent neurologic and cardiovascular complaints between April and December 2020 following COVID-19 infection. Twenty patients (70% female) were included in this study.Fifteen had POTS, 3 had neurocardiogenic syncope, and 2 had orthostatic hypotension. Six patients had abnormalities on cardiac or pulmonary testing, and 4 had elevated autoimmune or inflammatory markers. All patients were treated with non-pharmacologic therapies, and most required pharmacologic therapies. Six to 8 months after COVID-19, 17 (85%) patients had residual autonomic symptoms, with 12 (60%) unable to return to work. POTS can follow COVID-19 in previously healthy patients. Appropriate diagnostic investigations and therapies are necessary to identify and treat autonomic dysfunction after COVID-19.

To report a case series of patients with neuropathic POTS and cutaneous phosphorylated alpha-synuclein (P-SYN) deposition on skin biopsy and compare these to neuropathic POTS patients without P-SYN deposition. The medical history, physical examination findings, autonomic function testing, and skin biopsy neuropathology of patients under the age of 50 with a postural tachycardia and a diagnosis of POTS were retrospectively reviewed. Included patients completed the composite autonomic severity score (COMPASS 31), the Wood Mental Fatigue Inventory, the Epworth Sleepiness scale, the REM Behavior Disorder Questionnaire, the Patient-Reported Outcomes Measurement Information System (PROMIS-10), and the Gastroparesis Cardinal Symptom Index. Of 296 patients seen with POTS, 22 patients with suspected neuropathic POTS had skin biopsies performed during their evaluation. Seven of 22 patients had P-SYN present on skin biopsy, while 15 individuals did not. Those with P-SYN on biopsy: (1) were more likely to be male; (2) had features of REM sleep behavioral disorder; (3) reported less sleepiness and cognitive impairment; and (4) noted greater symptoms of gastroparesis. On autonomic testing, the group with P-SYN deposition was more likely to have a hypertensive response to tilt-table testing and abnormal QSART responses. Phosphorylated alpha-synuclein deposition is present in some postural tachycardia patients with neuropathic features. Individuals with a postural tachycardia and cutaneous phosphorylated alpha-synuclein deposition may be distinguished from other patients with neuropathic POTS.

Patients with acquired autonomic dysfunction may have antibodies specific to the ganglionic nicotinic acetylcholine receptor (gAChR). However, the clinical features of children and adolescents with acquired autonomic dysfunction (AAD) remain unclear. This study aimed to determine the clinical features of pediatric patients with acquired autonomic dysfunction. This study retrospectively examined a series of patients of AAD with serum gAChR antibodies who were referred to our laboratory for antibody testing between January 2012 and April 2019. The study included 200 patients (<20 years, 20 cases; ≥20 years, 175 cases) with clinical features of AAD. Upon comparing pediatric and adult patients, we found that antecedent infection and autonomic symptoms at onset with gastrointestinal symptoms occurred more frequently in children with AAD. We confirmed that four children (20.0%) met the diagnostic criteria for postural orthostatic tachycardia syndrome (POTS). A significantly higher number of children than adults had POTS (P = 0.002). In addition, upper GI dysfunction was more prevalent in children than in adults (P = 0.042). In particular, nausea and vomiting occurred in 60.0% of children with AAD and in 21.1% of adults (P < 0.001). The frequency of paralytic ileus was significantly higher in children with AAD (20.0%) relative to adults (6.3%) (P = 0.030). Regarding extra-autonomic manifestations, encephalopathy was more frequent in children (15.0%) than in adults (1.1%) (P < 0.001). Pediatric AAD patients have their own clinical characteristics, and these features may be unique to children and adolescents.

Postural tachycardia syndrome (POTS) is a heterogenous disorder of the autonomic nervous system that is commonly associated with small fiber neuropathy, Ehlers-Danlos Syndrome and autoimmune disorders, but association with rare conditions may also occur. Reported here are clinical features, diagnostic tests and treatment outcomes of 6 unique patients who presented with POTS and were subsequently diagnosed with Fabry disease, McArdle disease, Complex V mitochondrial disease, carcinoid tumor, Hodgkin's lymphoma and chemotherapy-induced neuropathy. All patients (age range 15-57 years, 3 females, 3 males) presented with orthostatic intolerance of at least 6 months duration, and all patients had co-morbid small fiber neuropathy. Five patients presented with symptoms of POTS months to years before the underlying or associated medical condition was discovered, and three out of six patients experienced either complete resolution or significant improvement of POTS after treatment of the underlying or associated medical condition. In rare cases, POTS can present as a possible manifestation of genetic, neoplastic or neurotoxic disorders. Unusual clinical features that fall outside of the typical spectrum of dysautonomia can point toward the presence of another disorder and help guide further diagnostic investigation.

[Figure: see text].

To report the intermediate-term outcome following surgical intervention for median arcuate ligament syndrome (MALS) in adolescents and young adults with orthostatic intolerance (OI) to assess clinical improvement in the gastrointestinal and 5 other functional domains and if relief of arterial obstruction is associated with resolution of clinical symptoms. Thirty-one patients were given 2 dysautonomia-designed questionnaires to assess changes in symptoms following operative intervention in 6 functional domains and underwent postoperative repeat abdominal ultrasound examinations. Average follow-up after surgery was 22.4 ± 14.8 months. Self-assessed quality of health on a Likert scale (1-10 with 10 being normal) improved from 4.5 ± 2.1 preoperatively to 5.3 ± 2.4 postoperatively (P = not significant). Gastrointestinal symptoms of abdominal pain, nausea, and vomiting improved in 63% (P = .007), 53% (P = .040), and 62% (P = .014) of patients, respectively. Cardiovascular symptoms of dizziness, syncope, chest pain, and palpitations improved in 45% (P = not significant), 50% (P = not significant), 54% (P = .043), and 54% (P = .037) of patients, respectively. Transabdominal ultrasound peak supine expiratory velocity decreased from 348 ± 105 cm/s preoperatively to 251 ± 109 cm/s at 6 months or more after a ligament release procedure. Decrease of the postoperative celiac artery Doppler velocity was not associated with an improvement in gastrointestinal symptoms (P = .075). Adolescent and young adult patients with median arcuate ligament syndrome and OI have a good response to surgical intervention. About two-thirds of patients report significant improvement in symptoms of abdominal pain, nausea, and vomiting. Despite these encouraging data, many patients with MALS and OI continue to have an impaired quality of health.

Postural orthostatic tachycardia syndrome (POTS) and restless legs syndrome (RLS) are both characterized by sleep disturbance along with autoimmune/inflammatory features and autonomic dysfunction. However, to our knowledge, there has been no direct study looking at the prevalence of RLS in patients with POTS patients compared with healthy participants (controls). Ninety-six physician-diagnosed patients with POTS (89 female and 7 male) and 130 controls (99 female and 31 male) were administered the Cambridge Hopkins questionnaire. Participants who were diagnosed with probable or definite RLS on the Cambridge Hopkins questionnaire were then contacted to determine the severity of RLS with the International Restless Legs Scale. More patients with POTS (15 of 96; 15.6%) than controls (6 of 130; 4.6%) were diagnosed with probable or definite RLS on the Cambridge Hopkins questionnaire (P = .0048). A sensitivity analysis with only female respondents yielded similar results. RLS severity was in the moderate range (12.23 ± 9.22). There is a higher prevalence of RLS in patients with POTS patients compared with controls. This association may have to do with shared increased inflammatory/autoimmune load and autonomic dysfunction.

Up to 90% of patients with postural tachycardia syndrome (PoTS) report headaches, and comorbid migraine headaches are common. Given this, pathophysiological interaction is possible, which may reveal key aspects of disease expression and treatment opportunities. We hypothesized that PoTS subjects-both with and without migraine-would show features of central sensitization, including allodynia and photophobia. Eighty participants were evaluated, including 30 PoTS, 30 chronic migraine (CM), and 20 non-headache healthy controls (NH), using tilt table testing, psychophysical assessment of sensory sensitivity thresholds, and an online questionnaire to assess measures of headache burden and associated symptoms. Clinical characteristics and sensory thresholds were compared between disease groups and controls, as well as in a subgroup analysis within the PoTS group, based on headache phenotype. Sensory sensitivity thresholds were significantly lower and symptom scores were higher in both the PoTS and CM groups compared to controls. However, the patterns of expression differed between PoTS and CM, with pain threshold reductions in the forearm only of PoTS subjects (non-trigeminal sensory sensitization), compared to both periorbital and forearm sites in CM. Unexpectedly, light sensitivity thresholds were significantly lower in PoTS than in both CM and NH. These findings reveal an underappreciated aspect of disease burden in PoTS, and suggest network sensitization similar to, but separable from, that of migraine. The presence of both photophobia and allodynia in PoTS is reflective of exteroceptive rather than strictly interoceptive disruption, and expands our fundamental understanding of the disorder.

Dysautonomia covers a range of clinical conditions with different characteristics and prognoses. They are classified as Reflex Syndromes, Postural Orthostatic Tachycardia Syndrome (POTS), Chronic Fatigue Syndrome, Neurogenic Orthostatic Hypotension (nOH) and Carotid Sinus Hypersensitivity Syndrome. Reflex (vasovagal) syndromes will not be discussed in this article. Reflex (vasovagal) syndromes are mostly benign and usually occur in patients without an intrinsic autonomic nervous system (ANS) or heart disease. Therefore, they are usually studied separately. Cardiovascular Autonomic Neuropathy (CAN) is the term most currently used to define dysautonomia with impairment of the sympathetic and/or parasympathetic cardiovascular autonomic nervous system. It can be idiopathic, such as multisystemic atrophy or pure autonomic failure, or secondary to systemic pathologies such as diabetes mellitus, neurodegenerative diseases, Parkinson's disease, dementia syndromes, chronic renal failure, amyloidosis and it may also occur in the elderly. The presence of Cardiovascular Autonomic Neuropathy (CAN) implies greater severity and worse prognosis in various clinical situations. Detection of Orthostatic Hypotension (OH) is a late sign and means greater severity in the context of dysautonomia, defined as Neurogenic Orthostatic Hypotension (nOH). It must be differentiated from hypotension due to hypovolemia or medications, called non-neurogenic orthostatic hypotension (nnOH). OH can result from benign causes, such as acute, chronic hypovolemia or use of various drugs. However, these drugs may only reveal subclinical pictures of Dysautonomia. All drugs of patients with dysautonomic conditions should be reevaluated. Precise diagnosis of CAN and the investigation of the involvement of other organs or systems is extremely important in the clinical suspicion of pandysautonomia. In diabetics, in addition to age and time of disease, other factors are associated with a higher incidence of CAN, such poor glycemic control, hypertension, dyslipidemia and obesity. Among diabetic patients, 38-44% can develop Dysautonomia, with prognostic implications and higher cardiovascular mortality. In the initial stages of DM, autonomic dysfunction involves the parasympathetic system, then the sympathetic system and, later on, it presents as orthostatic hypotension. Valsalva, Respiratory and Orthostatic tests (30:15) are the gold standard methods for the diagnosis of CAN. They can be associated with RR Variability tests in the time domain, and mainly in the frequency domain, to increase the sensitivity (protocol of the 7 tests). These tests can detect initial or subclinical abnormalities and assess severity and prognosis. The Tilt Test should not be the test of choice for investigating CAN at an early stage, as it detects cases at more advanced stages. Tilt response with a dysautonomic pattern (gradual drop in blood pressure without increasing heart rate) may suggest CAN. Treatment of patients at moderate to advanced stages of dysautonomia is quite complex and often refractory, requiring specialized and multidisciplinary evaluation. There is no cure for most types of Dysautonomia at a late stage. NOH patients can progress with supine hypertension in more than 50% of the cases, representing a major therapeutic challenge. The immediate risk and consequences of OH should take precedence over the later risks of supine hypertension and values greater than 160/90 mmHg are tolerable. Sleeping with the head elevated (20-30 cm), not getting up at night, taking short-acting antihypertensive drugs for more severe cases, such as losartan, captopril, clonidine or nitrate patches, may be necessary and effective in some cases. Preventive measures such as postural care; good hydration; higher salt intake; use of compression stockings and abdominal straps; portioned meals; supervised physical activity, mainly sitting, lying down or exercising in the water are important treatment steps. Various drugs can be used for symptomatic nOH, especially fludrocortisone, midodrine and droxidopa, the latter not available in Brazil. The risk of exacerbation or triggering supine hypertension should be considered. Chronic Fatigue Syndrome represents a form of Dysautonomia and has been renamed as a systemic disease of exercise intolerance, with new diagnostic criteria: 1 - Unexplained fatigue, leading to occupational disability for more than 6 months; 2 - Feeling ill after exercising; 3 - Non-restorative sleep; 4 - One of the following findings: cognitive impairment or orthostatic intolerance. Several pathologies today have evolved with chronic fatigue, being called chronic diseases associated with chronic fatigue. Postural orthostatic tachycardia syndrome (POTS), another form of presentation of dysautonomic syndromes, is characterized by sustained elevation of heart rate (HR) ≥30 bpm (≥40 bpm if <20 years) or HR ≥120 bpm, in the first 10 minutes in an orthostatic position or during the tilt test, without classical orthostatic hypotension associated. A slight decrease in blood pressure may occur. Symptoms appear or get worse in an orthostatic position, with dizziness, weakness, pre-syncope, palpitations, and other systemic symptoms being common.

Dyspnea in low-preload states is an underrecognized but growing diagnosis in patients with unexplained dyspnea. Patients can often experience debilitating symptoms at rest and with exertion, as low measured preload often leads to decreased cardiac output and ultimately dyspnea. In the present article, we performed a review of the literature and a multidisciplinary evaluation to understand the pathophysiology, diagnosis, and treatment of dyspnea in low-preload states. We explored selected etiologies and suggested an algorithm to approach unexplained dyspnea. The mainstay of diagnosis remains as invasive cardiopulmonary exercise testing. We concluded with a variety of nonpharmacological and pharmacological therapies, highlighting that a multifactorial approach may lead to the best results.

Major clinical centers in Sweden have witnessed an inflow of patients with chronic symptoms following initial outpatient care for coronavirus disease-2019 (COVID-19) infection, suggestive of postural orthostatic tachycardia syndrome. This report presents the first case series of 3 Swedish patients diagnosed with postural orthostatic tachycardia syndrome more than 3 months after the primary COVID-2019 infections. ().

Postural orthostatic tachycardia syndrome (POTS) is a cardiovascular autonomic disorder with poorly understood etiology and underlying pathophysiology. Since cardiovascular morbidity has been linked to growth hormone (GH), we studied GH levels in patients with POTS. We conducted an age-sex-matched case-control study in patients with POTS (age 31 ± 9 years; n = 42) and healthy controls (32 ± 9 years; n = 46). Plasma GH levels were measured using high-sensitivity chemiluminescence sandwich immunoassay. The burden of orthostatic intolerance symptoms was assessed by the Orthostatic Hypotension Questionnaire (OHQ), consisting of a symptom assessment scale (OHSA) and a daily activity scale (OHDAS). POTS patients had significantly higher composite OHQ score than controls, more symptoms and less activity. Supine heart rate and diastolic blood pressure (BP), but not systolic BP, were significantly higher in POTS. Median plasma GH levels were significantly lower in POTS (0.53 ng/mL) than controls (2.33 ng/mL, p = 0.04). GH levels were inversely related to OHDAS in POTS and supine systolic BP in POTS and controls, but not heart rate neither group. POTS is associated with lower GH levels. Impairment of daily life activities is inversely related with GH in POTS. A higher supine diastolic BP is inversely associated with GH levels in POTS and healthy individuals.

As a known phenomenon, crossover between sinus node dysfunction and common atrial tachyarrhythmias-most notably, atrial fibrillation and atrial flutter-in older individuals has previously been seen. Here, we present one of the first case series demonstrating a similar relationship between sinus node dysfunction and much rarer etiologies of tachyarrhythmia-that is, postural tachycardia syndrome and inappropriate sinus tachycardia. The exact pathological mechanisms behind these arrhythmias as well as the observation of concurrent nodal dysfunction are poorly understood. Here, we propose both potential mechanistic pathways as well as an initial treatment algorithm for sinus node dysfunction based upon the existing evidence.

Postural tachycardia syndrome (POTS), hypermobile Ehlers-Danlos syndrome (EDS), and mast cell activation syndrome (MCAS) can occur in the same patient. In this study, we investigated the relationship among these three syndromes. To establish the relationship of MCAS in patients diagnosed with POTS and hypermobile EDS as well as characterize the demographics of the patients affected by these syndromes. A total of 195 medical records of patients by using a diagnostic codes data base search for disorders of autonomic dysfunction were identified. The demographics of the patients and diagnoses of POTS, EDS, or MCAS were recorded. Confidence intervals of the proportion of patients MCAS within a population of patients with POTS and EDS were compared with the proportion of patients with MCAS and without POTS and EDS. Odds ratios were also calculated within these groups. The percentage of MCAS within the group of POTS and EDS was 31% in comparison with 2% within the non-POTS and EDS group. The 95% confidence interval calculated for the MCAS in the POTS and EDS group did not overlap with 2%, which showed a statistically significant result. The odds ratio between the two groups was found to be 32.46. There was a marked percentage of MCAS among the patients with diagnoses of POTS and EDS.

Postural tachycardia syndrome (POTS) is a form of autonomic dysfunction characterized by symptoms of orthostatic intolerance, often accompanied by sudomotor dysfunction and gastrointestinal dysmotility. Recently, evidence has accumulated that in a subset of patients, the pathogenesis of dysautonomia may be immune-mediated. The aim of the current report was to evaluate the use of intravenous immunoglobulin (IVIG) treatment in patients with progressive and/or refractory immune-mediated POTS. We retroactively assessed the effect and tolerance of monthly administered IVIG in six patients using autonomic function testing, standardized symptom questionnaires, and patients' symptom diaries both before and 6 months into IVIG treatment. Objective outcome measures included heart rate increase after 10 min of head-up tilt as well as duration and anhidrotic area in a thermoregulatory sweat test. Subjective outcome measures were patient reports and symptom ratings from the symptom questionnaire. All patients responded to immunomodulatory treatment, regardless of disease duration. After 6 months of IVIG, symptom severity was reduced by nearly 40%. Autonomic function testing showed improved cardiovascular functioning by 50% and a reduction of anhidrotic areas by one third. Overall, tolerance of IVIG treatment was poor, but could be improved by a reduction in infusion rate, premedication with steroids, and additional intravenous hydration. Using subjective but also standardized objective measures, the case series describes promising effects of IVIG treatment in POTS patients with immune-mediated dysautonomia. By reducing the infusion rate, pretreatment with steroids, and intravenous hydration, tolerance could be improved, and no patient had to discontinue the treatment.

Postural orthostatic tachycardia syndrome (POTS) is estimated to occur in up to 1% of adolescents, with symptoms of dizziness, fatigue, and pain impacting daily functioning. However, many risk factors and symptoms for POTS overlap with those of youth with disordered eating, and adolescents with POTS may be at increased risk for developing eating disorders. Therefore, the present study sought to better understand this overlap. We hypothesized that patients with POTS would have higher than expected rates of weight change, restrictive eating patterns, and food sensitivities. We conducted a retrospective chart review of 96 adolescents and young adults diagnosed with POTS who were participating in a 3-week intensive interdisciplinary pain rehabilitation program. We conducted descriptive and correlational statistical analyses on data from self-report measures, biomarkers of nutritional status, and abstracted information about eating and weight concerns from medical notes. Nearly 3 quarters of participants described engaging in restrictive eating, and more than half of them described experiencing weight loss. They also endorsed experiencing food allergies, celiac disease, and eating disorder at higher rates than would be expected in the general population. One-fifth of the sample had experienced invasive interventions to correct for nutritional imbalances, such as having a feeding tube. Weight and eating are clear areas of risk for patients with orthostatic intolerance. It is essential that treatment team members thoroughly screen for eating disturbances and make recommendations that support regular and balanced eating habits.

Post-Acute COVID-19 Syndrome (PACS) is defined by persistent symptoms >3-4 weeks after onset of COVID-19. The mechanism of these persistent symptoms is distinct from acute COVID-19 although not completely understood despite the high incidence of PACS. Cardiovascular symptoms such as chest pain and palpitations commonly occur in PACS, but the underlying cause of symptoms is infrequently known. While autopsy studies have shown that the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) rarely causes direct myocardial injury, several syndromes such as myocarditis, pericarditis, and Postural Orthostatic Tachycardia Syndrome have been implicated in PACS. Additionally, patients hospitalized with acute COVID-19 who display biomarker evidence of myocardial injury may have underlying coronary artery disease revealed by the physiological stress of SARS-CoV-2 infection and may benefit from medical optimization. We review what is known about PACS and the cardiovascular system and propose a framework for evaluation and management of related symptoms.