Dizziness can be protean with multiple phenotypes. One common phenotype in the young population is postural orthostatic tachycardia syndrome (POTS). POTS has a unique cardiovascular signature with a fascinating range of etiologies and pharmacodynamic substrates. This condition can pass undiagnosed for many years and is often mistaken as an anxiety disorder due to some of its hyperadrenergic manifestations. We present one such case and then flesh out the treatment strategies, both conservative and pharmacologic. We finally describe the various underlying pathophysiologic mechanisms of POTS and its sub-types and outline the various aberrant cardiovascular reflexes. We also describe the power spectra of the heart rate variability frequency bands and their underlying physiologic basis.

To develop an orthostatic intolerance symptom scoring system to assess orthostatic intolerance and then to compare the symptom score among different head-up tilt test responses. 272 subjects (5-18 years) presenting with orthostatic intolerance symptoms finished questionnaire and head-up tilt test. According to head-up tilt test hemodynamic responses, the subjects were divided into head-up tilt test negative, vasovagal syncope, and postural tachycardia syndrome groups. We built up a symptom score according to the frequency of dizziness, headache, blurred vision, palpitations, chest discomfort, gastrointestinal symptoms, profuse perspiration, and syncope. The median score in postural tachycardia syndrome subjects was highest. A score of 2.5 for predicting vasovagal syncope yielded a sensitivity of 75.0% and specificity of 50.3%, a score of 5.5 for predicting postural tachycardia syndrome yielded a sensitivity of 69.7% and specificity of 72.0%. Furthermore, the median score in postural tachycardia syndrome subjects was significantly higher than that in head-up tilt test negative subjects with heart rate increment of 30-39 beats/min ( < .01). This suggests that the symptom score has some predictive value in head-up tilt test results, which can be served as a preliminary assessment instrument.

Postural tachycardia syndrome (POTS) is a syndrome characterized by elevated heart rate without hypotension and most commonly occurs in young females (generally <35 years of age). The prevalence of POTS is on the rise, but the etiology is still under investigation, and there appear to be multiple potential physiologic causes. The majority of these patients experience a multitude of gastrointestinal (GI) and systemic symptoms and conditions that may contribute to functional debility and poor quality of life. Although symptoms generally improve with age, they can still lead to significant issues meeting nutrition and hydration needs. This paper summarizes the understood potential pathophysiology of POTS, associated GI and nutrition issues, general treatment of POTS, and strategies to assess and meet the unique nutrition and hydration needs of these patients.

Retrospective investigation of the somatosensory profile and prediction of histologic small fiber neuropathy (SFN) in postural orthostatic tachycardia syndrome (POTS) was performed using quantitative sensory testing (QST) as a standardized noninvasive test. In this investigation, full data sets from 30 patients (age: 34.03 ± 10.82 years, n = 6 males), including results of autonomic function testing, norepinephrine values, skin biopsy, and QST, were retrospectively analyzed. The QST data were compared with healthy controls (HCs) (age: 34.20 ± 10.5 years, n = 6 males, test: 0.95). The evaluation of all QST parameters in POTS compared with HCs yielded differences in all thermal parameters (cold detection threshold: < 0.05, warm detection threshold: < 0.001, thermal sensory limen: < 0.001, cold pain threshold: < 0.05, and heat pain threshold: < 0.001) and in paradoxical heat sensations ( < 0.05). Differences in nonpainful stimuli (mechanical detection threshold: < 0.05 and vibration detection threshold: < 0.001) were also detected. All patients who had clinical signs of SFN in combination with impairment of small fibers in QST also had SFN on skin biopsy. These results suggest that a non-region-specific SFN in POTS compared with controls can be detected by noninvasive QST that predicts histologic small fiber pathology.

To evaluate the association between quadrivalent human papillomavirus vaccination and syndromes with autonomic dysfunction, such as chronic fatigue syndrome, complex regional pain syndrome, and postural orthostatic tachycardia syndrome. Population-based self-controlled case series. Information on human papillomavirus vaccinations and selected syndromes with autonomic dysfunction (chronic fatigue syndrome, complex regional pain syndrome, and postural orthostatic tachycardia syndrome) identified using ICD-10 (international classification of diseases, revision 10) diagnostic codes from Danish nationwide registers. 869 patients with autonomic dysfunction syndromes from a cohort of 1 375 737 Danish born female participants aged 10 to 44 years during 2007-16. Self-controlled case series rate ratios (95% confidence intervals) of the composite outcome of chronic fatigue syndrome, complex regional pain syndrome, and postural orthostatic tachycardia syndrome, adjusted for age and season, comparing female participants vaccinated and unvaccinated with the quadrivalent human papillomavirus vaccine. Chronic fatigue syndrome, complex regional pain syndrome, and postural orthostatic tachycardia syndrome were also considered separately in secondary analyses. During 10 581 902 person years of follow-up, 869 female participants with syndromes of autonomic dysfunction (136 with chronic fatigue syndrome, 535 with complex regional pain syndrome, and 198 with postural orthostatic tachycardia syndrome) were identified. Quadrivalent human papillomavirus vaccination did not statistically significantly increase the rate of a composite outcome of all syndromes with autonomic dysfunction in a 365 day risk period following vaccination (rate ratio 0.99, 95% confidence interval 0.74 to 1.32) or the rate of any individual syndrome in the risk period (chronic fatigue syndrome (0.38, 0.13 to 1.09), complex regional pain syndrome (1.31, 0.91 to 1.90), or postural orthostatic tachycardia syndrome (0.86, 0.48 to 1.54)). When vaccination is introduced, adverse events could occur in close temporal relation to the vaccine purely by chance. These results do not support a causal association between quadrivalent human papillomavirus vaccination and chronic fatigue syndrome, complex regional pain syndrome, or postural orthostatic tachycardia syndrome, either individually or as a composite outcome. An increased risk of up to 32% cannot be formally excluded, but the statistical power of the study suggests that a larger increase in the rate of any syndrome associated with vaccination is unlikely.

The aims of the study were to perform the first systematic review of pediatric syncope etiologies and to determine the most common diagnoses with credible intervals (CredIs). Review was performed within Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and used Embase, Scopus, PubMed, and the Cochrane Controlled Trial databases. The following inclusion criteria for the articles were used: minimum of 10 patients, standard definition of syncope used, subjects who were 21 years or younger, and subjects who were either a consecutive retrospective group or a prospective group. No restrictions were made regarding language of the studies, but an English abstract was required. The following information was collected: purpose of the study, definition of syncope, number of patients, patient age range, inclusion/exclusion criteria, and etiologies of syncope. Of the 500 articles initially identified, 11 studies met the inclusion criteria and were the basis for this review. Three thousand seven hundred patients were included, ranging in age from 3 months to 21 years. The most common etiologies identified were vasovagal (52.2%; 95% CredI, 50.6-53.9), postural orthostatic tachycardia syndrome (13.1%; 95% CredI, 12.1-14.2), and cardiac causes (4.0%; 95% CredI, 3.39-4.65). A total of 18.3% (95% CredI, 17.0-19.5) of patients were found to have syncope of unknown cause. Syncope is a common pediatric complaint. Most cases seen are a result of benign causes, with only a small percentage because of serious medical conditions. In addition, most syncopal episodes in the pediatric population are diagnosed clinically or with minimally invasive testing, emphasizing the importance of a detailed history and physical examination.

More than one-fourth of all Persian gulf war coalition soldiers remain seriously ill. Several epidemiological studies suggest a link between multiple vaccinations at the time of the military operation and the illness development. Macrophagic Myofasciitis and post-HPV vaccination syndrome are two newer controversial vaccine-related disabling ailments. 1) To systematically review all original articles investigating the association of vaccines with gulf war illness, 2) To discuss gulf war illness, Macrophagic Myofasciitis, and post-HPV vaccination syndrome clinical similarities, 3) To discuss emergent pathogenetic mechanisms proposed for post-HPV vaccination syndrome that may be also relevant to gulf war illness and Macrophagic Myofasciitis. All original epidemiological studies (n = 11) found a positive association between vaccination and gulf war illness development. Chronic fatigue, widespread pain and cognitive impairment characterize the three syndromes under discussion. Anti-adrenergic receptor antibodies, dysautonomia and small fiber neuropathy have been recently described in patients with post-HPV vaccination syndrome. post-HPV vaccination syndrome, Macrophagic Myofasciitis, and gulf war illness analogy suggests that some vaccines or multiple vaccinations in a very short period of time may induce, in susceptible individuals, chronic pain, fatigue and dyscognition. Vaccine-induced autoimmune dysautonomia is hypothesized as the common pathogenetic mechanism for this symptom cluster. Further research on the presence of small fiber neuropathy, adrenergic receptor antibodies, and abnormal autonomic function tests in the three syndromes under discussion may help to elucidate this hypothesis.

To evaluate the ability of heart rate (HR) and HR difference during head-up tilt test (HUTT) and to predict clinical improvement related to metoprolol treatment in children and adolescents with postural tachycardia syndrome (POTS). This was a retrospective cohort study. A total of 53 subjects (27 male, aged 6-12 years old, mean age 11.79 ± 1.50 years old) with POTS treated with metoprolol were involved from July 2012 to September 2019. In total, 52 subjects who underwent health examination during the same period were matched as the control group. Subjects in both groups underwent HUTT. The HR distance between 5 minutes and 0 minutes (HR difference 5) and between 10 minutes and 0 minutes (HR difference 10) during HUTT was calculated. The POTS group was significantly greater than the control group in HR 5, HR 10, HR difference 5, and HR difference 10 (P < .01). There was no statistical difference in HR 0 between the 2 groups (P > .05). In total, 53 subjects with POTS were followed up for 96.0 (IQR, 40.5, 134.5) days during treatment with metoprolol. HUTT results demonstrated that 58.49% of subjects with POTS had a response and symptom scores were reduced after intervention. HR and HR difference were useful in predicting the efficacy of metoprolol on POTS. When HR 5, HR 10, HR difference 5, and HR difference 10, respectively, were ≥110, 112, 34, and 37 beats/min, the sensitivity and specificity were 82.50% and 69.23%, 84.62% and 69.70%, 85.29% and 89.47%, and 97.56% and 64.86%, respectively. HR and HR difference are helpful to predict the efficacy of metoprolol on POTS in children and adolescents.

Postural tachycardia syndrome (POTS) is a chronic form of orthostatic intolerance associated with cognitive dysfunction. We hypothesized executive function and attention is impaired in POTS during active standing. Eighty-seven POTS participants and 39 healthy controls of similar age, sex, and education level completed executive function (Stroop word-color) and attention (CogState Identification) tests in supine and standing postures in a cross-sectional study. POTS participants had lower executive function (t-score: 48 ± 11 vs. 55 ± 10 control; p = 0.009) and worse attention (reaction speed: 2.78 ± 0.11 vs. 2.69 ± 0.06 control; p < 0.001) during standing. These data provide new evidence that active standing impairs attention and executive functioning in POTS.

Psychological symptoms are frequently reported in patients with Postural Orthostatic Tachycardia Syndrome (POTS); however, the nature of these symptoms is not well understood. The current study described baseline psychological symptoms in patients with POTS, and examined associations between psychological and self-report autonomic symptoms. Participants reported mild anxiety symptoms, moderate depressive symptoms, severe somatization, and elevated anxiety sensitivity. Depressive symptoms and pain catastrophizing were significantly associated with autonomic symptoms. The current study adds to the literature by documenting elevated levels of anxiety sensitivity, and relationships between psychological and autonomic symptoms.

POTS patients undergo labial salivary gland biopsies (LSGB) for histologic confirmation of Sjogren's syndrome (SS). Predictive features of positive results are unknown. 161 POTS patients underwent LSGB. Their charts were reviewed for antibody and diagnostic testing results. Only 11% (17/161) of POTS patients were SS positive. There were more positive ANA antibodies in those with positive LSGB (65% v 28%, p = .0026). Positive skin nerve biopsy for small fiber neuropathy (SFN) was associated with positive LSGB (p = .046). A positive ANA and skin biopsy for SFN are two helpful features in selecting POTS patients for LSGB.

We herein report two new adolescent cases of Bier anemic spots, cyanosis, and urticaria-like eruption (BASCULE) syndrome. This rare, recently described condition may be associated with postural orthostatic tachycardia syndrome (POTS) and other forms of orthostatic intolerance. This report provides details on two cases and a literature review.

Reduced systolic/diastolic blood pressure (BP) by >40/20 mmHg defines initial orthostatic hypotension (IOH). Rapid resolution of hypotension and lightheadedness follows, but tachycardia may be prolonged. We aimed to examine IOH in controls and patients with postural tachycardia syndrome (POTS) using indices of spontaneous fluctuations of heart rate (HR) and systolic BP as measures of cardiac baroreflex differences. We recruited otherwise healthy IOH patients without POTS ( = 20, 16 ± 3 yr), healthy volunteers ( = 32, 17 ± 3 yr), and POTS patients ( = 39, 17 ± 4 yr). Subjects were instrumented for electrocardiography and beat-to-beat BP. After 10 min supine, subjects stood for 5 min. Following supine recovery, subjects underwent 70° head-up tilt for 10 min to test for POTS. BP, HR, and time, referenced to standing, were measured at events during standing: minimum BP, BP recovery, peak HR, HR minimum, and steady state. Baseline HR and BP were higher in POTS compared with healthy groups. IOH occurred in 13% of controls and 51% of POTS patients. The BP minimum was lower in POTS. Parasympathetic modulation of cardiac baroreflex was decreased in all POTS and control-IOH subjects. Sympathetic indices were increased. Events following BP minimum occurred progressively later in all POTS and control-IOH subjects compared with non-IOH controls. IOH is more frequent in POTS than in controls with a lower minimum BP. POTS has markedly reduced heart rate variability and baroreflex, indicating reduced HR buffering of BP. POTS-IOH and control-IOH subjects had similar peak HR despite decreased minimum BP in POTS. IOH data indicate modest parasympathetic and cardiovagal baroreflex deficits in control-IOH subjects. Parasympathetic deficits are more severe in all POTS patients. Significant initial orthostatic hypotension (IOH) occurs in ~50% of postural tachycardia syndrome (POTS) patients and 13% of controls. Heart rate and blood pressure recovery are prolonged in IOH sustaining lightheadedness; IOH is more prevalent and severe in POTS. Altered cerebral blood flow and cardiorespiratory regulation are more prevalent in POTS. Altered heart rate variability and baroreflex gain may cause nearly instantaneous lightheadedness in POTS. IOH alone fails to confer a strong probability of POTS.

Australia was the first country to implement a fully funded vaccination program with quadrivalent human papillomavirus vaccine (4vHPV) in 2007, including males from 2013. We examined adverse events (AE) following vaccination with 4vHPV from 11 years of post-marketing data, focusing on a period of enhanced surveillance and adverse events of special interest (AESI). AE following 4vHPV doses administered between April 2007 and December 2017 reported to Australia's national regulator, the Therapeutic Goods Administration, were examined; reports collected during enhanced surveillance in 2013 and 2014 were analyzed separately. Age and sex-specific rates, using denominator data from the national HPV vaccination register, were determined. Pre-specified AESI were identified using Medical Dictionary for Regulatory Activities (MedDRA®) Preferred Terms and examined in detail. Following nine million doses of 4vHPV vaccine administered in Australia, 4551 AE reports were identified. The crude reporting rate was 39.8 per 100 000 doses in the funded cohorts, excluding the enhanced surveillance period. The reported rate of syncope in 12 to 13-year-old males and females was 29.6 per 100 000 doses during enhanced surveillance and 7.1 per 100 000 doses during the remaining study period; rates of syncope were higher in younger compared to older adolescents. The rate of anaphylaxis (0.32 per 100 000 doses) was consistent with published rates. Other AESI including autoimmune disease, postural orthostatic tachycardia syndrome, primary ovarian insufficiency, Guillain-Barré syndrome, complex regional pain syndrome and venous thromboembolism, were reported at low rates and analysis did not reveal unexpected patterns that would suggest causal association. AESI, apart from syncope, were reported rarely. The higher rate of syncope among younger adolescents highlights the need for management protocols to prevent syncope-related injury. Analysis of this large, longitudinal dataset in a country with high vaccine uptake, including a period of enhanced surveillance, affirms the safety profile of 4vHPV.

Postural orthostatic tachycardia syndrome (POTS) is a multifactorial condition capable of chronically reducing the quality of life and the work ability of patients. The study aim was to assess the burden of autonomic symptoms in a cohort of POTS patients over 2 years. Patients' clinical profiles were assessed by the 31-item Composite Autonomic Symptom Score questionnaire (COMPASS 31) and a visual analog scale (VAS). One-way ANOVA for repeated measures followed by Dunnett's post-hoc test were used to compare symptoms at baseline and at 1 and 2 years. Out of 42 enrolled patients, 25 had a 1-year follow-up and 12 had a 2-year follow-up. At baseline, the reported burden of autonomic symptoms was high (overall COMPASS 31 = 49.9 ± 14.3 /100). Main complaints were related to orthostatic intolerance according to both COMPASS 31 and VAS. Fourteen patients were rendered inactive because of symptoms. At 1-year follow-up, a statistically significant improvement in pupillomotor function and overall score was detected by the COMPASS 31. These findings were confirmed at 2 years, together with a significant reduction in quality of life impairment, assessed by VAS. However, these improvements did not change patients' occupational status. Awareness of POTS diagnosis, patient monitoring, and tailored therapies can help to improve patients' condition.

Background Postural orthostatic tachycardia syndrome (POTS) is characterized by excessive heart rate increase on standing and orthostatic intolerance. Previous data indicate autoimmune involvement. We studied serum activity against G protein-coupled receptors in relation to symptoms in patients with POTS and controls using a commercial cell-based assay. Methods and Results Forty-eight patients with POTS (aged 28.6±10.5 years; 44 women) and 25 healthy individuals (aged 30.7±8.6 years; 21 women) were included. The 10-item Orthostatic Hypotension Questionnaire (OHQ) was completed by 33 patients with POTS and all controls. Human embryonic kidney 293 cells overexpressing one G protein-coupled receptor: adrenergic α receptor, adrenergic β receptor, cholinergic muscarinic type 2 receptor, and opioid receptor-like 1 were treated with sera from all patients. Receptor response was analyzed using a β-arrestin-linked transcription factor driving transgenic β-lactamase transcription by fluorescence resonance energy transfer method. Receiver operating characteristic curves were constructed. G protein-coupled receptor activation was related to OHQ indices in linear regression models. Sera from patients with POTS activated all 4 receptors to a higher degree compared with controls (<0.01 for all). The area under the curve was 0.88 (0.80-0.97, <0.001) combining all 4 receptors. Adrenergic α receptor activation associated with OHQ composite score (β=0.77 OHQ points per SD of activity, =0.009) and with reduced tolerability for prolonged standing (=0.037) and walking for short (=0.042) or long (=0.001) periods. All 4 receptors were associated with vision problems (<0.05 for all). Conclusions Our results indicate the presence of circulating proteins activating adrenergic, muscarinic, and nociceptin receptors in patients with POTS. Serum-mediated activation of these receptors has high predictive value for POTS. Activation of adrenergic α receptor is associated with orthostatic symptoms severity in patients with POTS.

Orthostatic intolerance (OI) and autonomic dysfunction (AD) are common in adolescents and young adults. Patients experience multisystem symptoms including gastrointestinal (GI), postural orthostatic tachycardia syndrome (POTS), orthostatic hypotension (OH), or only symptoms of OI (SOI) without significant findings on 70-degree head-up tilt testing (HUT). We hypothesize that patients with POTS, OH, and SOI show differences in GI symptoms and motility test and that heart rate (HR) changes on HUT predict severity of GI dysmotility. From medical records of patients (<18 years) with OI, we collected demographics, presenting symptoms, GI manifestations, and GI motility testing. Data were compared between the 3 groups (POTS, OH, and SOI). We assessed changes in HR on HUT with changes on GI motility evaluation. Two hundred twenty-nine patients were included (73% females). Abdominal pain (65%), nausea (49%), vomiting (18%), and constipation (24%) were the most common GI symptoms. In patients who had motility evaluation, there were 27% (53/193) with delayed gastric emptying (GE) at 4 hours, 35% (32/92) with delayed colonic transit (CT), 55% (17/31) with reduced gastric accommodation (GA), and 75% (21/28) with dyssynergic defecation (DD). Among 100 POTS, 34 OH, and 95 SOI patients, no significant differences in GI symptoms or motility tests were identified and HR changes on HUT were not associated with changes on motility tests. GI symptoms are frequent in adolescents with OI and are associated with delayed GE, reduced GA, delayed CT, and presence of DD.

Compression of the duodenum and left renal vein between the aorta and superior mesenteric artery usually leads to symptoms of proximal bowel obstruction or hematuria and, more rarely, nonspecific mild headaches. A young woman presented with new daily persistent headache refractory to numerous pharmacological treatments, onabotulinumtoxinA, nerve blocks, and occipital nerve stimulation. Following several years of daily severe headache, worsening abdominal pain and intolerance for food intake led to the discovery of aortomesenteric compression. Surgical treatment gave prompt improvement in gastric symptoms but also essentially resolved the headache. This is the first description of new daily persistent headache in association with aortomesenteric compression as well as marked improvement of headache following aortomesenteric decompression. In patients with new daily persistent headache and orthostatic symptoms one may consider a differential diagnosis of Nutcracker syndrome, especially in patients with comorbid hypermobility syndromes, hematuria or gastric symptoms.

Postural orthostatic tachycardia syndrome (POTS) is estimated to impact millions of people each year. However, there is no established gold standard for its treatment. Bupropion is a norepinephrine and a dopamine reuptake inhibitor and has been implicated as a potential treatment for POTS. We performed a non-randomized retrospective chart review on 47 patients with POTS with statistical analysis evaluating for significant findings including reduced orthostasis and improvement of symptoms with the use of bupropion. Bupropion was not associated with a statistically significant improvement in orthostatic vitals but there was an overall reduction in reported syncope. While the use of bupropion does not show a statistically significant impact on orthostatic vitals in patients with POTS, it did show a degree of improvement in syncope and as such might be useful in patients with syncope-predominant POTS.

Postural tachycardia syndrome (POTS) is a complex syndrome of orthostatic intolerance that significantly affects quality of life. The relationship between functional capacity, quality of life, and age remains poorly understood in this patient population. The purpose of this cross-sectional study was to assess the clinical and exercise characteristics of patients with POTS who underwent exercise stress testing as part of cardiac rehabilitation, and to evaluate the relationships between functional capacity with age and sex, as well as the relationship between functional capacity and quality of life. We included 255 consecutive adult patients with the diagnosis of POTS, by tilt table testing, who underwent exercise stress testing between 2012 and 2017. Clinical and stress test data were obtained from electronic medical records. Of the 255 patients, 232 (91%) were women, with median age 33.5 years. Prevalence of traditional CAD risk factors was low (2% diabetes, 13% hypertension, 7% hyperlipidemia, and 26% smoking history). Mean resting BP was 114 ± 13 mmHg systolic, resting HR was 76 ± 13 bpm, METs achieved 9.2 ± 2.2, and 1 min HR recovery 32 ± 17 bpm. 113 patients (44%) had abnormal functional capacity for age and sex. When analyzed by age groups, younger POTS patients had increasingly lower than expected functional capacity (compared to predicted normals) than did older patients (ANOVA  = 0.0017). The SF-36 physical component of patients with abnormal functional capacity was significantly lower than those with normal functional capacity. (p = 0.006). In this large cohort, patients with POTS were predominantly female (91%) and relatively young. The novel findings are that younger patients with POTS were more likely to have lower-than-average functional capacity for their age and sex compared to older patients, and that abnormal functional capacity was associated with lower quality of life by SF-36 physical component.

To evaluate the short-term effectiveness of reduced-osmolarity oral rehydration salt formulation (ORS) and propranolol in children diagnosed with postural orthostatic tachycardia syndrome (POTS) in head-up tilt testing (HUTT). Children were admitted with symptoms of orthostatic intolerance (OI) occurring in a standing position and disappearing in the supine position. Patients with heart rate increments of ≥40bpm and symptoms of OI constituted the pediatric POTS group in HUTT. A total of 70 pediatric patients with POTS were included in the study. POTS patients were divided into two groups based on whether they were prescribed reduced-osmolarity ORS and propranolol or not. The study group comprised patients on a regimen of reduced-osmolarity ORS and propranolol (n=34), while the control group comprised patients who were not prescribed any medication (n=36). The frequency of symptoms and standardized symptom scores were analyzed before and after 3 months of treatment in both groups. The post-treatment frequency of syncopal attacks was significantly reduced in both groups (P<0.01 for both groups), but the post-treatment standardized symptom scores were significantly reduced in the pediatric study group compared with the control group (P<0.01). The frequency of syncopal attacks was significantly reduced and the symptom scores for OI were improved in the study group. The improvement in OI symptom scores was better in the treatment group than in the control group. The control group symptoms persisted and caused extreme difficulty in their daily activities. In view of its clinical efficacy, we strongly advocate the use of combined treatment of reduced-osmolarity ORS and low-dose propranolol in pediatric patients with POTS.

Background Splanchnic venous pooling induced by upright posture triggers a compensatory increase in heart rate (HR), a response that is exaggerated in patients with postural tachycardia syndrome. To assess whether abdominal compression attenuates orthostatic tachycardia and improves symptoms, 18 postural tachycardia syndrome patients (32±2 years) were randomized to receive either abdominal compression (40 mm Hg applied with an inflatable binder ≈2 minutes before standing) or propranolol (20 mg) in a placebo-controlled, crossover study. Methods and Results Systolic blood pressure, HR, and symptoms were assessed while seated and standing, before and 2 hours postdrug. As expected, propranolol decreased standing HR compared with placebo (81±2 versus 98±4 beats per minute; <0.001) and was associated with lower standing systolic blood pressure (93±2 versus 100±2 mm Hg for placebo; =0.002). Compression had no effect on standing HR (96±4 beats per minute) but increased standing systolic blood pressure compared with placebo and propranolol (106±2 mm Hg; <0.01). Neither propranolol nor compression improved symptoms compared with placebo. In 16 patients we compared the combination of abdominal compression and propranolol with propranolol alone. The combination had no additional effect on standing HR (81±2 beats per minute for both interventions) but prevented the decrease in standing systolic blood pressure produced by propranolol (98±2 versus 93±2 mm Hg for propranolol; =0.029), and significantly improved total symptom burden (-6±2 versus -1±2 for propranolol; =0.041). Conclusions Splanchnic venous compression alone did not improve HR or symptoms but prevented the blood pressure decrease produced by propranolol. The combination was more effective in improving symptoms than either alone. Splanchnic venous compression can be a useful adjuvant therapy to propranolol in postural tachycardia syndrome. Registration URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT00262470.

To investigate the diagnostic and prognostic value of T-wave amplitude difference between supine and orthostatic electrocardiogram (ECG) in children and adolescents with postural orthostatic tachycardia syndrome (POTS). A total of 100 children and adolescents (POTS group, 50 males and 50 females, aged at 11.0 ± 2.4 years) diagnosed as POTS were enrolled from August 2013 to July 2016. Seventy-one children were matched as the control group according to age and sex. All cases completed the supine and orthostatic ECG. (a) Compared with the control group, the T-wave amplitude difference in leads I, II, aVL, V , V and V and the heart rate (HR) difference increased in POTS group. (b) Logistic regression analysis: The T-wave amplitude difference in leads V , V , and V and HR difference have statistical significance for POTS diagnosis. (c) Diagnostic test evaluation: When HR difference was ≥ 15 times/min, T-wave amplitude difference in lead V was ≥0.15 mV, T-wave amplitude difference in leads V and V were ≥0.10 mV, and the sensitivity and specificity of POTS diagnosis were 35.0% and 88.7%. (d) Follow-up: There was no significant difference in HR difference and T-wave amplitude difference in the nonresponse groups. In the response group, the T-wave amplitude difference in lead V was reduced than the initial value. The HR difference and T-wave amplitude difference in leads V4, V5, and V6 between supine and orthostatic ECG are of help in assisting the diagnosis of POTS but no obviously significance on prognosis estimation of it.

To study the frequency of latent and overt involuntary emotional expression disorder (IEED) in postural tachycardia syndrome (PoTS). We compared 51 PoTS patients with 15 neurally mediated hypotension (NMH) patients and 12 control subjects using the Center for Neurologic Study-Lability Scale (CNS-LS) for latent IEED and the PHQ-9 questionnaire for depression screening before head-up tilt (HUT). Overt IEED occurrence was observed during HUT. HUT precipitated overt IEED in 11 (22%) PoTS patients but not in NMH patients or controls. CNS-LS identified latent IEED in 23 (45%) PoTS patients, 5 (33%) NMH patients, and no control subjects. The CNS-LS tearfulness subscale was elevated in PoTS patients compared with controls (P = 0.0006). The PHQ-9 questionnaire scores were elevated in 69% of PoTS patients and 47% of NMH patients. The PHQ-9 score was higher in PoTS (<0.0001) and NMH (P = 0.0002) patients compared with controls. The study demonstrated frequent occurrence of latent IEED in PoTS and NMH and overt IEED in PoTS without "structural" involvement. HUT was a specific trigger for overt IEED in PoTS. Depression was co-morbid with PoTS. Neurohumoral and cerebral blood flow changes in supine position along with reduced gray matter volume in the insula and cingulate gyrus may underlie susceptibility to IEED. During HUT, cerebral hypoperfusion, rising epinephrine levels, and augmented autonomic arousal provide underpinnings for overt IEED. Clinicians should recognize this entity and counsel PoTS patients and their families. Limiting the duration of orthostatic stress may reduce morbidity.

We characterize the pediatric postural orthostatic tachycardia syndrome (POTS) population seen at a single tertiary care referral center. Retrospective chart review of all pediatric POTS patients seen in our center between 2015 and 2017. Pediatric POTS was defined as chronic, at least 3 months, symptoms of orthostatic intolerance associated with excessive orthostatic tachycardia as determined by tilt table testing with orthostatic heart rate increment of ≥40 bpm within 5 minutes of head-up tilt or absolute orthostatic heart rate ≥130 bpm for patients 13 years old and younger and ≥120 bpm for those 14 years and older. We looked at demographics, presenting symptoms, comorbidities, examination findings, investigation findings, treatment, and patient reported outcomes. Outcome measures were separated by patient report and group comparisons were made using 2-sample tests or Mann-Whitney tests for continuous variables and Fisher exact tests for categorical variables. One hundred thirty-four patients with pediatric onset POTS were identified. The mean age was 15 years. Seventy-nine percent of patients were female and 90% were white. The most common presenting symptoms included dizziness/lightheadedness (88%), syncope (54%), and palpitations (40%). Many patients had significant comorbidities attributable to numerous bodily systems, most commonly headache syndromes (migraine 43%, nonspecific headache 22%, chronic daily headache 14%, and new daily persistent headache 5%) and chronic fatigue (60%). Low vitamin D and insufficient iron stores were commonly seen. The majority of patients improved or had resolution of symptoms following treatment (70%). When separated by outcome, statistically significant differences were found for glucose (patients whose symptoms resolved had higher median glucose), palpitations (patients whose symptoms resolved were less likely to have palpitations), constipation (patients whose symptoms were stable/worsened were more likely to have constipation), and unexplained pain (patients whose symptoms were stable/worsened were more likely to have unexplained pain). Pediatric POTS is a chronic condition with a fairly good prognosis following appropriate treatment. It is associated with numerous comorbidities that necessitate multidisciplinary expert care.