The school nurse is often the first person with whom a student may discuss untoward health symptoms and concerns. Being cognizant of the clinical features of postural orthostatic tachycardia syndrome (POTS) will help the nurse alleviate some of the student's anxiety. Due to misunderstandings and misconceptions about POTS, family and peers may disbelieve a student who is experiencing symptoms. Displaying compassion and support will help the student understand that someone does believe his or her symptoms. As the student's advocate, the school nurse will champion a plan for the student's health and safety in the academic environment.

We hypothesize that upright cognitive impairment in patients with postural tachycardia syndrome (POTS) is caused by reduced cerebral blood flow (CBF). The CBF velocity (CBF(v)) measured by transcranial Doppler ultrasound decreased excessively during 70° tilt in a minority of patients with intermittent hyperpnea/hypocapnia. Incremental tilt showed no difference in mean CBF(v). But N-back memory tasking indicated progressive compromised memory, reduced functional hyperemia, and reduced neurovascular coupling. Orthostasis caused slow oscillations in CBF(v) linked to oscillations in arterial pressure in patients with POTS. We also hypothesize that oscillatory CBF(v) degrades neurovascular coupling. We performed 2-back testing when subjects were in supine position and during incremental tilts to 15°, 30°, 45°, and 60° in 11 patients with POTS and 9 controls. Oscillatory arterial pressure, oscillatory CBF(v), and neurovascular coupling were similar in supine position. The oscillatory arterial pressure increased by 31%, 45%, 67%, and 93% in patients with POTS during tilt and remained unchanged in the controls. Oscillatory CBF(v) increased by 61%, 82%, 161%, and 264% in patients with POTS during tilt and remained unchanged in the controls. Functional hyperemia decreased from 4.1% to 3.0%, 1.1%, 0.2%, and to 0.04% in patients with POTS, but it was unchanged at 4% in the controls. Percent correct N-back responses decreased from 78% to 33% in patients with POTS, whereas they remained at 89% in the controls. In patients with POTS, oscillatory CBF(v) was linearly correlated with functional hyperemia (r(2)=0.76). Increased oscillatory CBF is associated with reduced neurovascular coupling and diminished cognitive performance in patients with POTS.

Patients with the Postural Orthostatic Tachycardia Syndrome (POTS) have orthostatic intolerance, as well as exercise intolerance. Peak oxygen uptake (VO2peak) is generally lower in these patients compared with healthy sedentary individuals, suggesting a lower physical fitness level. During acute exercise, POTS patients have an excessive increase in heart rate and reduced stroke volume for each level of absolute workload; however, when expressed at relative workload (%VO2peak), there is no difference in the heart rate response between patients and healthy individuals. The relationship between cardiac output and VO2 is similar between POTS patients and healthy individuals. Short-term (i.e., 3 months) exercise training increases cardiac size and mass, blood volume, and VO2peak in POTS patients. Exercise performance is improved after training. Specifically, stroke volume is greater and heart rate is lower at any given VO2 during exercise after training versus before training. Peak heart rate is the same but peak stroke volume and cardiac output are greater after training. Heart rate recovery from peak exercise is significantly faster after training, indicating an improvement in autonomic circulatory control. These results suggest that patients with POTS have no intrinsic abnormality of heart rate regulation during exercise. The tachycardia in POTS is due to a reduced stroke volume. Cardiac remodeling and blood volume expansion associated with exercise training increase physical fitness and improve exercise performance in these patients.

Cardiovascular autonomic dysfunction is one of the most overlooked complications in patients with diabetes. We report the case of a 19-year-old woman with a 4-year history of diabetes referred due to palpitations and light-headedness following traumatic stress. Rise of heart rate and blood pressure during tilt table testing indicated hyperadrenergic postural orthstatic tachycardia syndrome (POTS). Elevated blood pressure variability, an indirect parameter of increased sympathetic activity, remained almost stable during orthostatic stress. Short-term treatment with ivabradine in combination with psychosocial support alleviated POTS-related symptoms. Our findings suggest that traumatic stress in patients with type 1 diabetes mellitus might translate into disturbed neural heart rate control due to a central, ephemeral alteration in autonomic balance.

Purpose Postural orthostatic tachycardia syndrome (POTS) is a form of orthostatic intolerance characterized by an increased heart rate upon transition from supine to standing, and head-up tilt without orthostatic hypotension. Its etiology is multifactorial, and no clear cause has been identified. Common symptoms include light-headedness, blurred vision, weakness, cognitive difficulties, and fatigue and are often accompanied by palpitations, shortness of breath, syncope, or gastrointestinal symptoms. Management includes volume expansion, physical counter maneuvers, and pharmacological agents such as fludrocortisone, midodrine, propranolol, and pyridostigmine. The course of POTS in pregnancy is variable and POTS has not been directly implicated in any adverse outcomes for the mother or fetus. Methods Two cases of POTS in pregnancy are presented, along with a review of the literature for reports of POTS in pregnancy. Results Along with our 2 cases, 10 other case reports were identified and included. Conclusion The course of POTS in pregnancy is variable, and not directly linked to increase perinatal morbidity or mortality. Women can safely undergo regional anesthesia, and vaginal delivery with close monitoring of hemodynamic changes.

Postural orthostatic tachycardia syndrome (POTS) is a type of dysautonomia seen most commonly in young women and children. It is defined as an increase in heart rate of 30 beats per minute (bpm) or more within 10 minutes of standing in adults, or by 40 bpm or more in children in the absence of orthostatic hypotension. In addition to typical autonomic symptoms, POTS patients report a wide range of subjective complaints in multiple organ systems, though the exact frequencies are unclear. To address the symptom frequency, we had 39 patients with POTS at our institution complete an intake form consisting of a list of 37 symptoms. The most frequently reported symptoms included palpitations, lightheadedness, and headache, although sleep disturbances, gastrointestinal complaints, sensitivity to temperature, and rash were also common.

Women with the postural orthostatic tachycardia syndrome (POTS) report fluctuations in orthostatic tolerance throughout the menstrual cycle. The mechanism(s) underlying blood pressure control across the menstrual cycle in women with POTS are unknown. The findings of the present study indicate that the menstrual cycle does not affect muscle sympathetic nerve activity but modulates blood pressure and vasoconstriction in POTS women during orthostatic stress. Factors other than sympathetic neural activity are likely responsible for the symptoms of orthostatic intolerance across the menstrual cycle in women with POTS. Patients with the postural orthostatic tachycardia syndrome (POTS) are primarily premenopausal women, which may be attributed to female sex hormones. We tested the hypothesis that hormonal fluctuations of the menstrual cycle alter sympathetic neural activity and orthostatic tolerance in POTS women. Ten POTS women were studied during the early follicular (EF) and mid-luteal (ML) phases of the menstrual cycle. Haemodynamics and muscle sympathetic nerve activity (MSNA) were measured when supine, during 60 deg upright tilt for 45 min or until presyncope, and during the cold pressor test (CPT) and Valsalva manoeuvres. Blood pressure and total peripheral resistance were higher during rest and tilting in the ML than EF phase; however, heart rate, stroke volume and cardiac output were similar between phases. There were no mean ± SD differences in MSNA burst frequency (8 ± 8 EF phase vs. 10 ± 10 bursts min(-1) ML phase at rest; 34 ± 15 EF phase vs. 36 ± 16 bursts min(-1) ML phase at 5 min tilt), burst incidence or total activity, nor any differences in the cardiovagal and sympathetic baroreflex sensitivities between phases under any condition. The incidence of presyncope was also the same between phases. There were no differences in haemodynamic or sympathetic responses to CPT or Valsalva. These results suggest that the menstrual cycle does not affect sympathetic neural activity but modulates blood pressure and vasoconstriction in POTS women during tilting. Thus, factors other than sympathetic neural activity are probably responsible for the symptoms of orthostatic intolerance across the menstrual cycle in women with POTS.

Fibroblasts from a patient with postural orthostatic tachycardia syndrome (POTS), who presented with low plasma choline and betaine, were studied to determine the metabolic characteristics of the choline deficiency. Choline is required for the synthesis of the phospholipid phosphatidylcholine (PC) and for betaine, an important osmoregulator. Here, choline transport, lipid homeostasis, and mitochondria function were analyzed in skin fibroblasts from POTS and compared with control cells. The choline transporter-like protein 1/solute carrier 44A1 (CTL1/SLC44A1) and mRNA expression were 2-3 times lower in POTS fibroblasts, and choline uptake was reduced 60% (P < 0.05). Disturbances of membrane homeostasis were observed by reduced ratios between PC:phosphatidylethanolamine and sphingomyelin:cholesterol, as well as by modified phospholipid fatty acid composition. Choline deficiency also impaired mitochondria function, which was observed by a reduction in oxygen consumption, mitochondrial potential, and glycolytic activity. When POTS cells were treated with choline, transporter was up-regulated, and uptake of choline increased, offering an option for patient treatment. The characteristics of the POTS fibroblasts described here represent a first model of choline and CTL1/SLC44A1 deficiency, in which choline transport, membrane homeostasis, and mitochondrial function are impaired.

Infections with human papilloma virus (HPV) can result in cervical, oropharyngeal, anal, and penile cancer and vaccination programs have been launched in many countries as a preventive measure. We report the characteristics of a number of patients with a syndrome of orthostatic intolerance, headache, fatigue, cognitive dysfunction, and neuropathic pain starting in close relation to HPV vaccination. Patients were referred for orthostatic intolerance following HPV vaccination. Symptoms of autonomic dysfunction were quantified by standardised questionnaire. The diagnosis of postural orthostatic tachycardia syndrome (POTS) rested on finding a sustained heart rate increment of >30 min(-1) (>40 min(-1) in adolescents) or to levels >120 min(-1) during orthostatic challenge. 35 women aged 23.3 ± 7.1 years participated. Twenty-five had a high level of physical activity before vaccination and irregular periods were reported by all patients not on treatment with oral contraception. Serum bilirubin was below the lower detection limit in 17 patients. Twenty-one of the referred patients fulfilled the criteria for a diagnosis of POTS (60%, 95%CI 43-77%). All patients had orthostatic intolerance, 94% nausea, 82% chronic headache, 82% fatigue, 77% cognitive dysfunction, 72% segmental dystonia, 68% neuropathic pain. In a population referred for symptoms of orthostatic intolerance and other symptoms consistent with autonomic dysfunction that began in close temporal association with a quadrivalent HPV vaccination, we identified a 60% prevalence of POTS. Further work is urgently needed to elucidate the potential for a causal link between the vaccine and circulatory abnormalities and to establish targeted treatment options for the affected patients.

We aimed to determine upright heart rate and blood pressure (BP) changes to suggest diagnostic criteria for postural orthostatic tachycardia syndrome (POTS) and orthostatic hypertension (OHT) in Chinese children. In this cross-sectional study, 1449 children and adolescents aged 6-18 years were randomly recruited from two cities in China, Kaifeng in Henan province and Anguo in Hebei province. They were divided into two groups: 844 children aged 6-12 years (group I) and 605 adolescents aged 13-18 years (group II). Heart rate and BP were recorded during an active standing test. 95th percentile (P(95)) of δ heart rate from supine to upright was 38 bpm, with a maximum upright heart rate of 130 and 124 bpm in group I and group II, respectively. P(95) of δ systolic blood pressure (SBP) increase was 18 mm Hg and P(95) of upright SBP was 132 mm Hg in group I and 138 mm Hg in group II. P(95) of δ diastolic blood pressure (DBP) increase was 24 mm Hg in group I and 21 mm Hg in group II, and P(95) of upright DBP was 89 mm Hg in group I and 91 mm Hg in group II. POTS is suggested when δ heart rate is ≥ 38 bpm (for easy memory, ≥ 40 bpm) from supine to upright, or maximum heart rate ≥ 130 bpm (children aged 6-12 years) and ≥ 125 pm (adolescents aged 13-18 years), associated with orthostatic symptoms. OHT is suggested when δ SBP (increase) is ≥ 20 mm Hg, and/or δ DBP (increase) ≥ 25 mm Hg (in children aged 6-12 years) or ≥ 20 mm Hg (in adolescents aged 13-18 years) from supine to upright; or upright BP ≥ 130/90 mm Hg (in children aged 6-12 years) or ≥ 140/90 mm Hg (in adolescents aged 13-18 years).

To investigate the total peripheral vascular resistance (TPVR), cardiac output (CO), and plasma C-type natriuretic peptide (CNP) levels in children with postural tachycardia syndrome (POTS) during supine, upright, and return to supine. Twenty-nine children with POTS, aged 12 ± 3 years, were recruited, and 32 healthy children, aged 11 ± 2 years, served as controls. Heart rate (HR), blood pressure, TPVR, and CO were continuously monitored with Finapres Medical System, and plasma CNP levels were detected with Sandwich immunoluminescence assay. In children with POTS, upright TPVR and CO were significantly lower than those in supine position, and they rose again when they returned to supine position. However, in healthy control patients, both TPVR and CO did not change during supine, upright, and supine again positions. Also, in the supine position, there was no significant difference in TPVR and CO between POTS children and control subjects (P > .05). When upright, however, TPVR and CO in children with POTS were significantly lower than those of controls. Plasma CNP levels were significantly greater in children with POTS than that of controls (32.8 ± 9.7 vs 24.2 ± 8.4 [pg/mL], P < .01), and symptom scores and ΔHR positively correlated with plasma CNP levels in children with POTS (symptom scores: r = 0.490, P < .01; ΔHR: r = 0.508, P < .001), but CO negatively correlated with plasma CNP levels (r = -0.446, P < .01). Reduced TPVR and CO associated with the elevated plasma CNP might be involved in the pathogenesis of POTS.

The objective of this study was to determine the effect of inspiratory resistance through an impedance threshold device (ITD) on orthostatic tolerance in patients with postural tachycardia syndrome. We hypothesized that the ITD would result in a greater negative intrathoracic pressure to enhance cardiac venous return, improve stroke volume, and reduce heart rate in these patients. We compared the effect of a sham device (sham, no resistance) versus an ITD (increased inspiratory resistance) in 26 patients with postural tachycardia syndrome in a randomized, single-blind, crossover study. Hemodynamic assessments were performed at baseline while supine and during head-up tilt to 70° for 10 minutes. We did not find differences in baseline hemodynamic parameters between the ITD and the sham devices. After 10 minutes of head-up tilt, the heart rate was lower with the ITD versus sham device (102±4 versus 109±4 beat/min, respectively; P=0.003). The ITD also improved stroke volume compared with the sham device (35±2 versus 26±1 mL; P=0.006). These findings suggest that increasing negative intrathoracic pressure with ITD breathing improves heart rate control in patients with postural tachycardia syndrome during upright posture. clinicaltrials.gov; Unique Identifier: NCT00962728.

To assess haemodynamic patterns in head-up tilt testing on 400 paediatric cases with unexplained syncope. Medical records of 520 children who underwent head-up tilt testing in the preceding year were retrospectively evaluated, and 400 children, 264 (66%) girls and 136 (34%) boys, aged 12.6±2.6 years (median 13; range 5-18), with unexplained syncope were enrolled in the study. Age, sex, baseline heart rate, baseline blood pressure, frequency of symptoms, and/or fainting attacks were recorded. The test protocol consisted of 25 minutes of supine resting followed by 20 minutes of 70° upright positioning. Subjects were divided into nine groups according to their differing haemodynamic patterns. There were no statistically significant differences between the groups with regard to age, gender, baseline blood pressure, and frequency of syncope (p>0.05). The response was compatible with orthostatic intolerance in 28 cases (7.0%), postural orthostatic tachycardia syndrome in 24 cases (6.0%), asymptomatic postural orthostatic tachycardia syndrome in 26 cases (6.5%), orthostatic hypotension in seven cases (1.7%), vasovagal syncope in 38 cases (9.5%), and negative in 274 cases (69.2%). Vasovagal syncope response patterns were of type 3 in nine cases (2.2%), type 2A in 10 cases (2.5%), type 2B in two cases (0.5%), and type 1 (mixed) in 17 cases (4.25%). In the 400 paediatric cases with unexplained syncope, nine different haemodynamic response patterns to head-up tilt testing were discerned. Children with orthostatic intolerance syndromes are increasingly referred to hospitals because of difficulty in daily activities. Therefore, there is need for further clinical trials in these patient groups.

Vaccination has been one of the most effective public health measures in the history of medicine. However, seemingly inexplicit adverse reactions have been described after the injection of the newer vaccines vs. human papillomavirus (HPV). The symptoms more often reported are chronic pain with paresthesias, headaches, fatigue, and orthostatic intolerance. Adverse reactions appear to be more frequent after HPV vaccination when compared to other type of immunizations. Different isolated cases and small series have described the development of complex regional pain syndrome (CRPS), postural orthostatic tachycardia syndrome (POTS), and fibromyalgia after HPV vaccination. These are illnesses often difficult to diagnose that have overlapping clinical features. Sympathetic nervous system dysfunction seems to play a major role in the pathogenesis of these syndromes. Also, small fiber neuropathy has been recently recognized in CRPS, POTS, and fibromyalgia. This article forwards the hypothesis that small fiber neuropathy and dysautonomia could be the common underlying pathogenesis to the group of rare, but severe reactions that follow HPV vaccination. Clinicians should be aware of the possible association between HPV vaccination and the development of these difficult to diagnose painful dysautonomic syndromes.

To determine if several multisystem comorbid conditions occur more frequently in subjects with tilt-table defined postural tachycardia syndrome (POTS) compared with those without. Retrospective chart review of 67 subjects aged 6-24 years, referred to a tertiary care neurogastroenterology and autonomic disorders clinic for a constellation of functional gastrointestinal, chronic pain, and autonomic complaints. All patients underwent formal autonomic testing, Beighton scores assessment for joint hypermobility (0-9), and fibromyalgia tender points (0-18) (43 subjects). Twenty-five subjects (37%) met tilt table criteria for POTS. The median age of 16 years (range, 12-24 years) in the POTS group differed from 15 years (range, 6-21 years) in the no-POTS group (P = .03). Comorbidities including chronic fatigue, sleep disturbances, dizziness, syncope, migraines, functional gastrointestinal disorders, chronic nausea, fibromyalgia, and joint hypermobility did not differ between groups. All subjects with fibromyalgia by tender point-examination had a Beighton score ≥ 4 (P = .002). Comorbid conditions are equally prevalent in children and young adults with and without tilt-table defined POTS, suggesting that POTS itself is not a cause of the other comorbidities. Instead, POTS likely reflects another comorbid condition in children with functional disorders. Dizziness and syncope, classically associated with POTS, are not predictive of a diagnosis of POTS by tilt table, a test that is still required for formal diagnosis. These results suggest a paradigm shift in the concept of POTS as the physiological basis of many functional symptoms.

We present the case of a patient with chronic fatigue secondary to Postural Orthostatic Tachycardia Syndrome (POTS) who had distinctive abnormalities in his arterial waveform morphology as assessed by pulse oximetry. Moreover, the patient's arterial waveform changed markedly from being supine to upright, suggesting that arterial flow patterns may be abnormal in our patient. Analysis of the waveform suggested a positional hypovolemia as the cause of his orthostatic intolerance. We review general aspects of arterial flow waveform analysis pertinent to health care providers and discuss the pathophysiology of POTS.

Postural orthostatic tachycardia syndrome (POTS) is a relatively rare syndrome recognised since 1940. It is a heterogenous condition with orthostatic intolerance due to dysautonomia and is characterised by rise in heart rate above 30 bpm from base line or to more than 120 bpm within 5-10 min of standing with or without change in blood pressure which returns to base line on resuming supine position. This condition present with various disabling symptoms such as light headedness, near syncope, fatigue, nausea, vomiting, tremor, palpitations and mental clouding, etc. However there are no identifiable signs on clinical examination and patients are often diagnosed to have anxiety disorder. The condition predominantly affects young female between the ages of 15-50 but is rarely described in older people. We describe an older patient who developed POTS which recovered over 12 mo. Recognising this condition is important as there are treatment options available to alleviate the disabling symptoms.

Postural tachycardia syndrome (POTS) is a common form of chronic orthostatic intolerance. The remarkable increase in heart rate (HR) upon standing is the hallmark of this syndrome. Treatment of POTS patients is challenging and includes drugs that slow the HR. Ivabradine is a selective If channel blocker designed to slow the HR, as an anti-anginal agent. In view of its ability to slow the HR, we posited that ivabradine may be an ideal medication for treating POTS patients. This report provides the results of an investigation in which we studied ivabradine's effect on the hemodynamics and sympathovagal balance in POTS patients. An open-label trial, without a placebo control, was performed in eight patients with POTS of two years' standing. Characterization of symptoms, hemodynamics, autonomic function tests, and HR and blood pressure (BP) variability were determined while patients were in a supine position and during a 20-minute head-up tilt before and after a single oral dose of 7.5 mg ivabradine. Ivabradine slowed the HR of POTS patients at rest by 4±1 bpm (P<0.05). During a 5-minute head-up tilt, the HR decreased from 118±4 bpm to 101±5 bpm (P<0.01). Ivabradine did not affect the BP when patients were at rest in a supine position or in head-up tilt position. Cardiovascular vagal and sympathetic tone, extrapolated from the time and frequency domains of the HR and BP variability, were also not affected by ivabradine. Ivabradine is an effective drug for slowing the HR of POTS patients at rest and during tilting, without producing significant adverse effects. Moreover, ivabradine exerts its effects without influencing the sympathovagal balance.

Healthy subjects with asymptomatic postural tachycardia at baseline were evaluated over a one year period to determine whether they developed non-postural versus orthostatic symptoms that could predispose them to develop Postural Tachycardia Syndrome (POTS). Participants (n=30) were recruited for a 1-year follow-up (FUP) study if at baseline they demonstrated a heart rate increment of ≥30bpm on head-up tilt (HUT). At FUP, HUT was repeated and four self-report questionnaires were used to assess symptoms. Heart rate (HR) increment was reduced in 19 subjects (-11.8±7.4bpm) and increased in 11 subjects (8.3±6.1bpm) at FUP versus baseline. Heart rate increment at FUP demonstrated no correlation to general fatigue (r=0.006), body vigilance (r=0.195), or the component scores for physical (r=-0.087) and mental (r=-0.137) health of the SF-36. Similarly, there was no correlation between HR increment at FUP and orthostatic scores (r=0.04). However, orthostatic scores did show a significant positive correlation with general fatigue and body vigilance scores (r=0.374, r=0.392, respectively; p<0.05). Despite meeting the heart rate criteria for POTS, these findings further support that the majority of young individuals express benign orthostatic tachycardia. In addition, after one year this patient population showed no predisposition to develop non-postural or postural symptoms that could lead to the full syndrome of POTS. These data further argue for the re-evaluation of the heart rate criteria for diagnosing POTS in young populations.

Orthostatic intolerance (OI) syndromes are a confusing topic and determining a specific diagnosis to achieve optimal treatment can be troublesome. We sought to assess biomarker, hemodynamic and autonomic variables in OI patients (autonomic dysfunction [AD], postural orthostatic tachycardia syndrome [POTS] and neurally mediated syncope [NMS]) and healthy controls during supine and head-up tilt position in order to achieve a better diagnosis. In response to head-up tilt, patients with AD presented a marked decrease in systolic blood pressure (SBP) (p=0.002), and a blunted increase in heart rate (HR) (p=0.04). Baroreceptor gain was almost absent in supine position and did not change in response to tilt. Patients with POTS had lower values of atrial natriuretic peptide (p=0.03) but similar neurohormonal biomarkers and hemodynamic and baroreceptor function in supine position compared to healthy subjects. However, in response to head-up tilting greater reductions in stroke volume (p=0.008) and baroreceptor gain (p=0.002) and greater rises in HR (p=0.001), total peripheral resistance (p=0.008), low frequency component of SBP variability (LF-SBP) (p=0.003) and plasma noradrenaline (p=0.03) were observed. Patients with NCS had similar biomarkers and autonomic indices to healthy subjects in supine position, but a larger decrease in baroreceptor gain (p=0.007) and a greater rise in LF-SBP (p=0.004) and plasma adrenaline (p=0.003) response to head-up tilting. Although different OI syndromes share similar symptoms, including blurred vision, syncope and dizziness particularly during orthostatism, they differ markedly regarding biochemical, autonomic and hemodynamic parameters. Assessment of these differences may be helpful for better diagnosis and management.

Postural tachycardia syndrome (POTS) is a form of chronic orthostatic intolerance for which the hallmark physiological trait is an excessive increase in heart rate with assumption of upright posture. The orthostatic tachycardia occurs in the absence of orthostatic hypotension and is associated with a >6-month history of symptoms that are relieved by recumbence. The heart rate abnormality and orthostatic symptoms should not be caused by medications that impair autonomic regulation or by debilitating disorders that can cause tachycardia. POTS is a "final common pathway" for a number of overlapping pathophysiologies, including an autonomic neuropathy in the lower body, hypovolemia, elevated sympathetic tone, mast cell activation, deconditioning, and autoantibodies. Not only may patients be affected by more than one of these pathophysiologies but also the phenotype of POTS has similarities to a number of other disorders, e.g., chronic fatigue syndrome, Ehlers-Danlos syndrome, vasovagal syncope, and inappropriate sinus tachycardia. POTS can be treated with a combination of non-pharmacological approaches, a structured exercise training program, and often some pharmacological support.

Postural tachycardia syndrome (POTS) is a syndrome of excessive tachycardia with orthostatic challenge, and relief of such symptoms with recumbence. There are several proposed subtypes of the syndrome, each with unique pathophysiology. Numerous symptoms such as excessive tachycardia, lightheadedness, blurry vision, weakness, fatigue, palpitations, chest pain, and tremulousness are associated with orthostatic intolerance. Other co-morbid conditions associated with POTS are not clearly attributable to orthostatic intolerance. These include chronic headache, fibromyalgia, functional gastrointestinal or bladder disorders, cognitive impairment, and sleep disturbances. Dermatological manifestations of POTS are also common and wide ranging, from livedo reticularis to Raynaud's phenomenon, from cutaneous flushing to erythromelalgia. Here, we provide three illustrative cases of POTS with dermatological manifestations. We discuss the potential pathophysiology underlying such dermatological manifestations, and how such mechanisms could in turn help guide development of management.

Syncope is a common problem with a large differential diagnosis. The initial history and physical examination often provide initial clues; however, some cases warrant further testing to determine the underlying cause. Autonomic function testing is a safe way to evaluate patients with syncope further, and to assess their parasympathetic and sympathetic nervous systems. Autonomic testing can help to diagnose several conditions, including orthostatic hypotension, delayed orthostatic hypotension, postural tachycardia syndrome and neutrally mediated syncope. Thus, when the cause of syncope is unclear, autonomic testing can help to assess the autonomic nervous system, stratify the risk of future episodes and to guide treatment decisions.

In recent years, there have been a number of studies suggesting that POTS may have an autoimmune etiology. This study examined whether the prevalence of antinuclear antibodies (ANA), other markers of autoimmunity and co-morbid autoimmune disorders is higher in patients with POTS than in the general population. Medical records of 100 consecutive patients with POTS evaluated at our clinic were reviewed. In this cohort (90% females, mean age 32, range 13-54 years), 25% had positive ANA, 7% had at least one positive aPL antibody and 31% had markers of autoimmunity. When compared to the general population, patients with POTS had a higher prevalence of ANA (25% vs. 16%, OR 1.8, CI 1.1-2.8, p < 0.05), aPL antibody (7% vs. 1%, OR 7.5, CI 3.4-16.1, p < 0.001) and co-morbid autoimmune disorders (20% vs. highest estimated 9.4%, OR 2.4, CI 1.5-3.9, p < 0.001). The most prevalent autoimmune disorder was Hashimoto's thyroiditis (11% vs. up to 2%, OR 6.1, CI 3.2-11.3, p < 0.001), followed by RA (4% vs. up to 1%, OR 4.1, CI 1.5-11.2, p < 0.01) and SLE (2% vs. up to 0.12%, OR 17, CI 4.1-69.7, p < 0.001). The prevalence of CVID was very high (2% vs. 0.004%, OR 510.2, CI 92.4-2817.8, p < 0.001), while celiac disease showed a nonsignificant trend toward increased prevalence. Patients with POTS have a higher prevalence of autoimmune markers and co-morbid autoimmune disorders than the general population. One in four patients have positive ANA, almost one in three have some type of autoimmune marker, one in five have a co-morbid autoimmune disorder, and one in nine have Hashimoto's thyroiditis.

Chronic pain in children and adolescents can be difficult for a single provider to manage in a busy clinical setting. Part of this difficulty is that pediatric chronic pain not only impacts the child but also the families of these children. In this review article, we discuss etiology and pathophysiology of chronic pain, along with variables that impact the severity of chronic pain and functional loss. We review diagnosis and management of selected chronic pain conditions in pediatric patients, including headache, low back pain, hypermobility, chronic fatigue, postural orthostatic tachycardia syndrome, abdominal pain, fibromyalgia, and complex regional pain syndrome. For each condition, we create a road map that contains therapy prescriptions, exercise recommendations, and variables that may influence pain severity. Potential medications for these pain conditions and associated symptoms are reviewed. A multidisciplinary approach for managing children with these conditions, including pediatric pain rehabilitation programs, is emphasized. Lastly, we discuss psychological factors and interventions for pediatric chronic pain and potential complementary and alternative natural products and interventions.