Outcomes in Adolescents with Postural Orthostatic Tachycardia Syndrome Treated with Midodrine and β-Blockers

Poincaré plot can help predict the curative effect of metoprolol for pediatric postural orthostatic tachycardia syndrome

Purpose

To study whether a Poincaré plot can help predict the curative effect of metoprolol for postural orthostatic tachycardia syndrome (POTS) in children.

Methods

Pediatric patients with POTS who were administered metoprolol were retrospectively included. The collected data included general data (sex, age, height, weight, and body mass index), the manifestations and treatment (baseline orthostatic intolerance symptom score and course of metoprolol treatment), vital signs (supine heart rate [HR], supine blood pressure, and increased HR during the standing test), HR variability indexes (standard deviation of normal-to-normal intervals [SDNN]; standard deviation of the averages of normal-to-normal intervals [SDANN]; mean standard deviation of the NN intervals for each 5-min segment [SDNNI]; root mean square of the successive differences [rMSSD]; percentage of adjacent NN intervals that differ by >50 ms [pNN50]; triangular index; ultra-low [ULF], very low [VLF], low [LF], and high frequency [HF]; total power [TP]; and LF/HF ratio), and graphical parameters of the Poincaré plot (longitudinal axis [L], transverse axis [T], and L/T). Receiver operator characteristic curves were used to calculate the predictive function of the indexes with significant differences between patients who responded and those who did not. The index combination with the highest predictive value was obtained through series-parallel analysis.

Results

Overall, 40 responders and 23 non-responders were included. The L and T in the Poincaré plots and rMSSD, pNN50, HF, and TP of the HR variability data were significantly lower in participants who responded to metoprolol than in participants who did not (p < 0.001). The L/T of participants who responded to metoprolol was greater than that of non-responders (p < 0.001). Moreover, we noted a strong correlation between every two indexes among L, T, rMSSD, pNN50, HF, TP, and L/T (p < 0.05). T < 573.9 ms combined with L/T > 2.9 had the best performance for predicting the effectiveness of metoprolol, with a sensitivity of 85.0%, specificity of 82.6%, and accuracy of 84.1%.

Conclusion

In the Poincaré plot, a T < 573.9 ms combined with an L/T > 2.9 helps predict good outcomes of using metoprolol to treat pediatric POTS.

Postural Orthostatic Tachycardia Syndrome in Spinal Cord Injury

Spinal cord injury (SCI), in addition to motor and sensory problems, may also lead to autonomic dysfunction. Postural orthostatic tachycardia syndrome (POTS) is one of them and has often been reported in traumatic brain injuries, multiple sclerosis, and other spinal cord pathologies. However, there is not much data on POTS in SCI even in extensive databases. We present a case of an adolescent female with paraplegia due to traumatic SCI. During her tilt table training, she started having episodes of sinus tachycardia associated with fatigue, dizziness, headache, palpitations, and presyncope with no orthostatic hypotension, after achieving 60 degrees of head tilt. After ruling out the common causes of tachycardia and syncope, a diagnosis of POTS was established. With pharmacologic and non-pharmacological measures, including metoprolol, increased fluid intake, and compression stockings, her symptoms resolved, and she was able to continue rehabilitation.

Orthostatic intolerance in post-concussion patients

Orthostatic intolerance (OI) following pediatric concussion is not well understood. Assessing the prevalence of concussion-related OI and how it compares to non-concussion-related OI will improve care for patients suffering with these symptoms. OBJECTIVE: We set out to describe concussion-related OI in adolescence, with particular emphasis on time to recovery and differences from non-concussion-related OI (including male vs. female prevalence). Retrospective chart reviews were completed on post-concussion patients endorsing symptoms of OI. The patients' sex, sport history, previous concussions, time since injury, and recovery time were analyzed and compared between males and females as well as against general OI statistics. Thirty-nine pediatric patients, representing 8.7% of all new patients referred to a specialized concussion clinic over a 13-month interval, were included in the chart review. Mean age of onset was 15.0 ± 2.5 years and 18 (46%) were males. The median times from evaluation to symptom resolution were 120 days. Of 18 patients who completed head-up tilt table testing, 17 (94%) had orthostatic tachycardic response (>40 bpm heart rate increment). Post-concussive OI differs from other orthostatic intolerance etiologies, lacking a strong female predominance and exhibiting a shorter time course to recovery compared to other etiologies of OI (but longer recovery time compared to concussion patients in general). Clinical orthostatic vital signs may not be sensitive for diagnosing orthostatic intolerance in athletes, likely due to higher vagal tone and more efficient skeletal muscle pump.

Pediatric Postural Orthostatic Tachycardia Syndrome: Where We Stand

Postural orthostatic tachycardia syndrome (POTS), first described in 1992, remains an enigmatic, yet severely and variably debilitating, disorder. The pathophysiology of this syndrome is still not understood, and there remains no biomarker indicating the presence of POTS. Although research interest has increased in recent years, there are relatively fewer clinical and research studies addressing POTS in children and adolescents compared with adults. Yet, adolescence is when a large number of cases of POTS begin, even among adult patients who are subsequently studied. This article summarizes reported research in POTS, specifically in pediatric patients, including discussion of aspects of diagnostic criteria, risk factors and outcomes, neurohormonal and hemodynamic abnormalities, clinical assessment, and treatment. The goals of this review are increased recognition and acknowledgment of POTS among pediatric and adolescent providers, as well as to provide an understanding of reported abnormalities of homeostasis, such that symptomatic patients will be able to be recognized and appropriately managed, enabling them to return to their activities of daily living.

Biomarkers and Hemodynamic Parameters in the Diagnosis and Treatment of Children with Postural Tachycardia Syndrome and Vasovagal Syncope

In children, vasovagal syncope and postural tachycardia syndrome constitute the major types of orthostatic intolerance. The clinical characteristics of postural tachycardia syndrome and vasovagal syncope are similar but their treatments differ. Therefore, their differential diagnosis is important to guide the correct treatment. Therapeutic methods vary in patients with the same diagnosis because of different pathomechanisms. Hence, in patients with vasovagal syncope or postural tachycardia syndrome, routine treatments have an unsatisfactory efficacy. However, biomarkers could increase the therapeutic efficacy significantly, allowing for an accurate and detailed assessment of patients and leading to improved therapeutic effects. In the present review, we aimed to summarize the current state of research into biomarkers for distinguishing the diagnosis of pediatric vasovagal syncope from that of postural tachycardia syndrome. We also discuss the biomarkers that predict treatment outcomes during personalized therapy for each subtype.

Baseline Corrected QT Interval Dispersion Is Useful to Predict Effectiveness of Metoprolol on Pediatric Postural Tachycardia Syndrome

OBJECTIVES

The study was designed to explore the role of baseline-corrected QT interval dispersion (QTcd) in predicting the effectiveness of metoprolol on pediatric postural tachycardia syndrome (POTS).

METHODS

There were two groups in the study, the discovery group and the validation group. The children with POTS in the discovery group were treated with oral metoprolol, with the completed necessary medical records, head-up tilt test (HUTT), blood chemistry, and 12-lead ECG before treatment at the pediatrics of Peking University First Hospital, China. According to whether the symptom score (SS) was reduced by more than 2 points after administration with oral metoprolol as compared with that before treatment, the children with POTS were separated into responders and non-responders. The demographic characteristics, hemodynamic indicators, and the QTcd of the two groups were compared, and the estimate of the baseline QTcd in predicting the treatment response to metoprolol was tested through a receiver operating characteristic (ROC) analysis. Other 24 children suffering from POTS who were, administrated with metoprolol at the pediatrics of Peking University First Hospital were included in the validation group. The sensitivity, specificity, and accuracy of the baseline QTcd in the prediction of the effectiveness of metoprolol on POTS were validated in children.

RESULTS

The pre-treatment baseline QTcd in responders treated with metoprolol was longer than that of the non-responders in the discovery group [(66.3 ± 20.3) ms vs. (45.7 ± 19.9) ms, p = 0.001]. The baseline QTcd was negatively correlated with SS after metoprolol treatment (r = -0.406, p = 0.003). The cut-off value of baseline QTcd for the prediction of the effectiveness of metoprolol on pediatric POTS was 47.9 ms, yielding a sensitivity of 78.9% and a specificity of 83.3%, respectively. The validation group showed that the sensitivity, specificity, and accuracy of the baseline QTcd ≥ 47.9 ms before treatment for estimating the effectiveness of metoprolol on POTS in children were 73.7, 80.0, and 75.0%, respectively.

CONCLUSION

Baseline QTcd is effective for predicting the effectiveness of metoprolol on pediatric POTS.

Baseline left ventricular ejection fraction associated with symptom improvements in both children and adolescents with postural tachycardia syndrome under metoprolol therapy

BACKGROUND

Postural tachycardia syndrome (POTS) is a common childhood disease that seriously affects the patient's physical and mental health. This study aimed to investigate whether pre-treatment baseline left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) values were associated with symptom improvement after metoprolol therapy for children and adolescents with POTS.

METHODS

This retrospective study evaluated 51 children and adolescents with POTS who received metoprolol therapy at the Peking University First Hospital between November 2010 and July 2019. All patients had completed a standing test or basic head-up tilt test and cardiac echocardiography before treatment. Treatment response was evaluated 3 months after starting metoprolol therapy. The pre-treatment baseline LVEF and LVFS values were evaluated for correlations with decreases in the symptom score after treatment (ΔSS). Multivariable analysis was performed using factors with a P value of <0.100 in the univariate analyses and the demographic characteristics.

RESULTS

A comparison of responders and non-responders revealed no significant differences in demographic, hemodynamic characteristics, and urine specific gravity (all P > 0.050). However, responders had significantly higher baseline LVEF (71.09% ± 4.44% vs. 67.17% ± 4.88%, t = -2.789, P = 0.008) and LVFS values (40.00 [38.00, 42.00]% vs. 36.79% ± 4.11%, Z = -2.542, P = 0.010) than the non-responders. The baseline LVEF and LVFS were positively correlated with ΔSS (r = 0.378, P = 0.006; r = 0.363, P = 0.009), respectively. Logistic regression analysis revealed that LVEF was independently associated with the response to metoprolol therapy in children and adolescents with POTS (odds ratio: 1.201, 95% confidence interval: 1.039-1.387, P = 0.013).

CONCLUSIONS

Pre-treatment baseline LVEF was associated with symptom improvement after metoprolol treatment for children and adolescents with POTS.

Postural orthostatic tachycardia syndrome (POTS): State of the science and clinical care from a 2019 National Institutes of Health Expert Consensus Meeting - Part 1

Postural orthostatic tachycardia syndrome (POTS) is a chronic and often disabling disorder characterized by orthostatic intolerance with excessive heart rate increase without hypotension during upright posture. Patients often experience a constellation of other typical symptoms including fatigue, exercise intolerance and gastrointestinal distress. A typical patient with POTS is a female of child-bearing age, who often first displays symptoms in adolescence. The onset of POTS may be precipitated by immunological stressors such as a viral infection. A variety of pathophysiologies are involved in the abnormal postural tachycardia response; however, the pathophysiology of the syndrome is incompletely understood and undoubtedly multifaceted. Clinicians and researchers focused on POTS convened at the National Institutes of Health in July 2019 to discuss the current state of understanding of the pathophysiology of POTS and to identify priorities for POTS research. This article, the first of two articles summarizing the information discussed at this meeting, summarizes the current understanding of this disorder and best practices for clinical care. The evaluation of a patient with suspected POTS should seek to establish the diagnosis, identify co-morbid conditions, and exclude conditions that could cause or mimic the syndrome. Once diagnosed, management typically begins with patient education and non-pharmacologic treatment options. Various medications are often used to address specific symptoms, but there are currently no FDA-approved medications for the treatment of POTS, and evidence for many of the medications used to treat POTS is not robust.

Treatment of Postural Orthostatic Tachycardia Syndrome With Medication: A Systematic Review

PURPOSE

Postural orthostatic tachycardia syndrome has been recognized for decades, but treatment is largely based on anecdotal experience and expert opinion. Pharmacologic treatment is inconsistent and unstandardized. We did a systematic review to identify controlled studies from which informed treatment decisions can be made.

METHOD

Through a standard systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we identified all English-language studies of a medication treatment for postural orthostatic tachycardia syndrome that included a comparison or control group and followed outcomes for at least 1 week of treatment.

RESULTS

A total of 626 studies were identified by the search criteria, and 8, involving a total of 499 patients, met the criteria. No studies were adequately similar to allow for meta-analysis. Of the identified 8 studies, 2 were randomized controlled trials and 4 had been subjected to peer review. In individual studies, there was some favorable effect with fludrocortisone, beta blockers, midodrine, and selective serotonin reuptake inhibitors.

CONCLUSION

There is a paucity of high-quality data about effectiveness of medication in the treatment of postural orthostatic tachycardia syndrome. Nonetheless, 2 randomized trials and 6 other reports show some favorable effects of medication.

Clinical Prognostic Factors in Pediatric Patients With Orthostatic Intolerance

Midodrine is widely used for orthostatic intolerance (OI); however, little is known about the prognostic factors of OI after midodrine treatment. We retrospectively reviewed electronic medical charts to investigate clinical prognostic factors of OI on 159 OI patients aged 7 to 18 years who were treated with midodrine at a children's hospital. Logistic regression was conducted to clarify predictors for improving symptoms at the first month of the treatment. Patients with orthostatic uncomfortable feeling or fainting were significantly more likely to improve symptoms at the first month of the treatment (odds ratio [OR], 3.48; 95% confidence interval [95%CI], 1.36-8.89), but patients with underweight were significantly less likely to improve symptoms (OR, 0.19; 95%CI, 0.06-0.56). Our results suggest that predictive factors for OI by midodrine treatments are orthostatic symptoms and underweight in pediatric patients. These findings are useful to develop further studies for OI treatments.

Postural Tachycardia Syndrome in Children and Adolescents: Pathophysiology and Clinical Management

Postural tachycardia syndrome (POTS), characterized by chronic (≥6 months) orthostatic intolerance symptoms with a sustained and excessive heart rate increase while standing without postural hypotension, is common in children and adolescents. Despite the unclear pathogenesis of POTS, the present opinion is that POTS is a heterogeneous and multifactorial disorder that includes altered central blood volume, abnormal autonomic reflexes, "hyperadrenergic" status, damaged skeletal muscle pump activity, abnormal local vascular tension and vasoactive factor release, mast cell activation, iron insufficiency, and autoimmune dysfunction. A number of pediatric POTS patients are affected by more than one of these pathophysiological mechanisms. Therefore, individualized treatment strategies are initiated in the management of POTS, including basal non-pharmacological approaches (e.g., health education, the avoidance of triggers, exercise, or supplementation with water and salt) and special pharmacological therapies (e.g., oral rehydration salts, midodrine hydrochloride, and metoprolol). As such, the recent progress in the pathogenesis, management strategies, and therapeutic response predictors of pediatric POTS are reviewed here.

Functional capacity and quality of life in the postural tachycardia syndrome: A retrospective cross-sectional study

Background

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.

Methods

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.

Results

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 P = 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).

Conclusions

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.

Pathophysiology and Individualized Management of Vasovagal Syncope and Postural Tachycardia Syndrome in Children and Adolescents: An Update

Vasovagal syncope (VVS) and postural tachycardia syndrome (POTS) are the main forms of orthostatic intolerance in pediatrics and both are underlying causes of neurally-mediated syncope. In recent years, increasing attention has been paid to the management of VVS and POTS in children and adolescents. A number of potential mechanisms are involved in their pathophysiology, but the leading cause of symptoms varies among patients. A few studies thus have focused on the individualized treatment of VVS or POTS based on selected hemodynamic parameters or biomarkers that can predict the therapeutic effect of certain therapies and improve their effectiveness. This review summarizes the latest developments in individualized treatment of VVS and POTS in children and indicates directions for further research in this field.

The Relationship Between Hypermobile Ehlers-Danlos Syndrome (hEDS), Postural Orthostatic Tachycardia Syndrome (POTS), and Mast Cell Activation Syndrome (MCAS)

In recent years, an association between hypermobile Ehlers-Danlos syndrome (hEDS), mast cell activation syndrome (MCAS), and postural orthostatic tachycardia syndrome (POTS) has garnered attention and patients are increasingly presenting with this triad. However, a real relationship between these entities is unclear due to a lack of scientific validity. We conducted an extensive review of the literature using two different search strategies. A narrower strategy included 88 searches of various combinations of terms for each of the three conditions, yielding 19 unique papers. A broader search included 136 searches of various combinations of terms but included all forms of EDS and yielded 40 unique papers. Of these, only four and nine papers from the narrower and broader search strategies were original research articles. None of these papers resulted from a combination of the search terms for the three conditions. All three clinical entities are controversial in either existence or pathogenesis. MCAS is a poorly defined clinical entity, and many studies do not adhere to the proposed criteria when establishing the diagnosis. Patients previously diagnosed with EDS hypermobility type may not meet the new, stricter criteria for hEDS but may for a less severe hypermobility spectrum disorder (HSD). The pathophysiology of POTS is still unclear. An evidence-based, common pathophysiologic mechanism between any of the two, much less all three conditions, has yet to be described. Our review of the literature shows that current evidence is lacking on the existence of MCAS or hEDS as separate or significant clinical entities. Studies proposing a relationship between the three clinical entities are either biased or based on outdated criteria. The reason behind the purported association of these entities stems from an overlapping pool of vague, subjective symptoms, which is inadequate evidence to conclude that any such relationship exists.

Heart Rate Variability Predicts Therapeutic Response to Metoprolol in Children With Postural Tachycardia Syndrome

PURPOSE

To improve the metoprolol therapeutic effectiveness, we aimed to explore whether baseline heart rate variability (HRV) indicators before metoprolol treatment were useful for predicting its efficacy for postural tachycardia syndrome (POTS).

METHODS

We recruited 45 children with POTS who received metoprolol and 17 healthy controls. All children underwent a standing test or basic head-up tilt test and 24-h dynamic electrocardiography before treatment. After 3 months of metoprolol, therapeutic responsiveness was evaluated. The usefulness of baseline HRV parameters in predicting the effectiveness of metoprolol was studied and the long-term cumulative symptom rate was analyzed.

RESULTS

The baseline HRV frequency domain indicators for power, ultra-low frequency, very-low frequency, low frequency (LF), high frequency (HF), and total power (TP) as well as time domain indicators were significantly lower for responders than non-responders to metoprolol; however, low-frequency normalized units and LF/HF ratio were markedly greater for responders than non-responders. On series-parallel analysis, combined baseline triangular (TR) index ≤ 33.7 and standard deviation of all normal-to-normal intervals (SDNN) index ≤ 79.0 ms as cut-off values yielded sensitivity, specificity and accuracy of 85.3, 81.8, and 84.4%, respectively, to predict therapeutic responsiveness to metoprolol. On long-term follow-up, the cumulative symptom rate was significantly higher with TR index > 33.7 and SDNN index ≤ 79.0 ms, TR index ≤ 33.7 and SDNN index > 79.0 ms or TR index > 33.7 and SDNN index > 79.0 ms than TR index ≤ 33.7 and SDNN index ≤ 79.0 ms (P < 0.05).

CONCLUSION

Combined TR index ≤ 33.7 and SDNN index ≤ 79.0 ms were useful preliminary measures to predict therapeutic response to metoprolol in pediatric POTS.

Pain Management In Pediatric Patients With Postural Orthostatic Tachycardia Syndrome: Current Insights

Pediatric patients with postural orthostatic tachycardia syndrome (POTS) often present with co-occurring struggles with chronic pain (POTS+pain) that may limit daily activities. POTS is a clinical syndrome characterized by orthostatic symptoms and excessive postural tachycardia without orthostatic hypotension. Active research from the medical and scientific community has led to controversy over POTS diagnosis and treatment, yet patients continue to present with symptoms associated with POTS+pain, making treatment recommendations critical. This topical review examines the literature on diagnosing and treating pediatric POTS+pain and the challenges clinicians face. Most importantly, clinicians must employ an interdisciplinary team approach to determine the ideal combination of pharmacologic (e.g., fludrocortisone), non-pharmacologic (e.g., physical therapy, integrative medicine), and psychological (e.g., cognitive behavioral therapy, psychoeducation) treatment approaches that acknowledge the complexity of the child's condition, while simultaneously tailoring these approaches to the child's personal needs. We provide recommendations for treatment for youth with POTS+pain based on the current literature.

Postural orthostatic tachycardia syndrome: clinical presentation, aetiology and management

Postural orthostatic tachycardia syndrome (POTS) is a variant of cardiovascular autonomic disorder characterized by an excessive heart rate increase on standing and orthostatic intolerance. POTS affects younger individuals 15-45 years old with a distinct female predominance (≈80%). The prevalence ranges between 0.2% and 1.0% in developed countries. The onset of POTS is typically precipitated by immunological stressors such as viral infection, vaccination, trauma, pregnancy, surgery or psychosocial stress. The most common complaints are dizziness, weakness, rapid heartbeat and palpitation on standing. Moreover, patients often report physical deconditioning and reduced exercise capacity as well as headache, 'brain fog', dyspnoea, gastrointestinal disorders and musculoskeletal pain. The aetiology of POTS is largely unknown and three main hypotheses include an autoimmune disorder, abnormally increased sympathetic activity and catecholamine excess, and sympathetic denervation leading to central hypovolaemia and reflex tachycardia. The golden standard for POTS diagnosis is head-up tilt test with a non-invasive beat-to-beat haemodynamic monitoring. Although long-term prognosis of POTS is poorly explored, around 50% of patients spontaneously recover within 1-3 years. After the diagnosis has been established, patient should be thoroughly educated about non-pharmacological measures alleviating the symptoms. Exercise training may be very effective and counteract deconditioning. In more symptomatic patients, different drugs directed at controlling heart rate, increasing peripheral vasoconstriction and intravascular volume can be tested. However, the overall effects of pharmacological therapy are modest and the most affected patients remain handicapped. Future efforts should focus on better understanding of POTS pathophysiology and designing randomized controlled trials for selection of more effective therapy.

Postural tachycardia syndrome - Diagnosis, physiology, and prognosis

Postural tachycardia syndrome (POTS) is a heterogeneous clinical syndrome that has gained increasing interest over the past few decades due to its increasing prevalence and clinical impact on health-related quality of life. POTS is clinically characterized by sustained excessive tachycardia upon standing that occurs in the absence of significant orthostatic hypotension and other medical conditions and or medications, and with chronic symptoms of orthostatic intolerance. POTS represents one of the most common presentations of syncope and presyncope secondary to autonomic dysfunction in emergency rooms and in cardiology, neurology, and primary care clinics. The most sensitive method to detect POTS is a detailed medical history, physical examination with orthostatic vital signs or brief tilt table test, and a resting 12-lead electrocardiogram. Additional diagnostic testing may be warranted in selected patients based on clinical signs. While the precise etiology remains unknown, the orthostatic tachycardia in POTS is thought to reflect convergence of multiple pathophysiological processes, as a final common pathway. Based on this, POTS is often described as a clinical syndrome consisting of multiple heterogeneous disorders, with several underlying pathophysiological processes proposed in the literature including partial sympathetic neuropathy, hyperadrenergic state, hypovolemia, mast cell activation, deconditioning, and immune-mediated. These clinical features often overlap, however, making it difficult to categorize individual patients. Importantly, POTS is not associated with mortality, with many patients improving to some degree over time after diagnosis and proper treatment. This review will outline the current understanding of diagnosis, pathophysiology, and prognosis in POTS.

Utilisation of medications to reduce symptoms in children with postural orthostatic tachycardia syndrome

BACKGROUND

Postural orthostatic tachycardia syndrome encompasses multiple disabling symptoms that interfere with daily activities. Non-pharmacologic approaches can be insufficient and can require adjunctive medications to manage symptoms. Minimal data exist in the literature on medication outcomes in these patients. We reviewed our database for medication management outcomes.Materials and MethodsPatients aged 18 years and younger at initial diagnosis met the inclusion criteria. All prescribed patient medications were extracted from the electronic health record, excluding medications for unrelated symptoms or comorbid diseases. Medications were grouped by symptom class consistent with our programme utilisation protocol. Within symptom classification, therapy was deemed successful when a specific dose was prescribed at least five consecutive times without changes; this was confirmed by chart review. Individual medications and overall percentage of successful therapies within symptom classifications were assessed, with further analysis by gender. t-Test, χ2, and Mann-Whitney U-test were used to assess for differences in specific variables, as appropriate.

RESULTS

A total of 708 patients met the study criteria. The percentage of patients with effective therapy by symptom includes light-headedness (52.2%), headache (48.2%), nausea (39.1%), dysmotility (43.4%), pain (53.4%), and insomnia (42.8%). Insomnia therapy was better for females; all other therapies showed no gender difference. The median number of therapies prescribed per patient per symptom was 2 for light-headedness, headache, and insomnia, and 1 for nausea, dysmotility, and pain.DiscussionSymptoms associated with this disorder can be effectively managed with various medications. Further randomised studies are needed to better ascertain true efficacy compared with placebo.

Efficacy of Therapies for Postural Tachycardia Syndrome: A Systematic Review and Meta-analysis

OBJECTIVE

To identify the evidence base and evaluate the efficacy of each treatment for postural tachycardia syndrome (POTS) in light of a recent consensus statement highlighting the lack of treatment options with clear benefit to risk ratios for this debilitating condition.

METHODS

The CENTRAL (Cochrane Central Register of Controlled Trials), PubMed, and Embase databases from inception to May 2017 were searched using the terms postural AND tachycardia AND syndrome. A total of 135 full-text publications were screened after excluding duplicates (n=681), conference abstracts (n=467), and records that did not relate to POTS therapy (n=876). We included 28 studies with at least 4 patients with POTS in which symptomatic response was reported after more than 4 weeks of therapy. This review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Two investigators independently performed the data extraction and evaluated the quality of evidence.

RESULTS

This study comprised 25 case series and 3 small randomized controlled trials that evaluated 755 and 103 patients with POTS, respectively. Interventions directed at increasing intravascular volume, increasing peripheral or splanchnic vascular tone, controlling heart rate, and increasing exercise tolerance demonstrate moderate efficacy (range, 51%-72%). Few data exist on their comparative effectiveness. Significant heterogeneities were seen in terms of patient age, symptom severity, and the measures used to evaluate treatment efficacy.

CONCLUSION

The current evidence base to guide optimal management of patients with POTS is extremely limited. More high-quality collaborative research with standardized reporting of symptom response and treatment tolerability is urgently needed.

Efficacy of Propranolol, Bisoprolol, and Pyridostigmine for Postural Tachycardia Syndrome: a Randomized Clinical Trial

Postural tachycardia syndrome (POTS) is a form of dysautonomia which presents with complex symptoms including orthostatic intolerance. Several medications are prescribed for POTS; however, the efficacy of sustained medical treatment has not been well-investigated. Here, we conducted a 2 × 2 factorial design, randomized, clinical trial of a 3-month medical treatment regimen in POTS patients. Patients were randomly allocated to 4 treatment groups (Group 1: propranolol; Group 2: bisoprolol; Group 3: propranolol + pyridostigmine; Group 4: bisoprolol + pyridostigmine). The orthostatic intolerance questionnaire (OIQ), Beck depression inventory-II (BDI-II), and short-form health survey (SF-36) were conducted at baseline, 1 and 3 months after treatment. Seventy-seven patients who completed the 3-month follow-up were analyzed. In total, every clinical score improved significantly after medical treatment. The OIQ score was significantly lower than that at baseline (18.5 ± 6.7) after 1 month (12.5 ± 4.5, P < 0.01), which decreased further after 3 months (7.8 ± 5.7, P < 0.01). The OIQ score improvements were consistent across every treatment group. In the subgroup analysis of 59 patients who did not receive antidepressants, the BDI-II score significantly decreased after treatment, regardless of the regimen. Physical components of the SF-36 improved after 3 months in every group, while mental components improved only in Group 3. The amount of changes in each score was similar among groups throughout the comparisons. Sustained medical treatment is beneficial to POTS patients, not only for orthostatic intolerance symptoms but also for depression and diminished quality of life, even without prescriptions for antidepressants. The efficacy of each regimen in POTS patients was comparable.

TRIAL REGISTRATION

NCT02171988.

Interdisciplinary Treatment of Maladaptive Behaviors Associated with Postural Orthostatic Tachycardia Syndrome (POTS): A Case Report

The prevalence of postural orthostatic tachycardia syndrome (POTS) in adolescents and young adults has been increasing during the past decade. Despite this increase, documentation regarding treatment of these patients is just beginning to emerge. In addition, despite a call for a multidisciplinary or interdisciplinary approach, no studies have examined the efficacy of such an approach to treatment. This paper describes a case study of a 19-year-old male with debilitating POTS seen at a tertiary clinic for evaluation and subsequent intensive interdisciplinary treatment. The treatment approach is described and outcomes are presented.

Pediatric Disorders of Orthostatic Intolerance

Orthostatic intolerance (OI), having difficulty tolerating an upright posture because of symptoms or signs that abate when returned to supine, is common in pediatrics. For example, ∼40% of people faint during their lives, half of whom faint during adolescence, and the peak age for first faint is 15 years. Because of this, we describe the most common forms of OI in pediatrics and distinguish between chronic and acute OI. These common forms of OI include initial orthostatic hypotension (which is a frequently seen benign condition in youngsters), true orthostatic hypotension (both neurogenic and nonneurogenic), vasovagal syncope, and postural tachycardia syndrome. We also describe the influences of chronic bed rest and rapid weight loss as aggravating factors and causes of OI. Presenting signs and symptoms are discussed as well as patient evaluation and testing modalities. Putative causes of OI, such as gravitational and exercise deconditioning, immune-mediated disease, mast cell activation, and central hypovolemia, are described as well as frequent comorbidities, such as joint hypermobility, anxiety, and gastrointestinal issues. The medical management of OI is considered, which includes both nonpharmacologic and pharmacologic approaches. Finally, we discuss the prognosis and long-term implications of OI and indicate future directions for research and patient management.

Improvement in Functioning and Psychological Distress in Adolescents With Postural Orthostatic Tachycardia Syndrome Following Interdisciplinary Treatment

Significant functional impairment and psychological distress have been observed in adolescent patients with postural orthostatic tachycardia syndrome (POTS). Interdisciplinary rehabilitation programs have been shown to be beneficial in the treatment of chronic pain in adults and adolescents. Only preliminary data have examined interdisciplinary rehabilitation efforts in patients with POTS. This study evaluated the impact of an interdisciplinary rehabilitation program on the functional impairment and psychological distress in 33 adolescents diagnosed with POTS. Patients included in the study were adolescents ages 11 to 18 diagnosed with POTS. Measures completed at admission and discharge from the program included the Functional Disability Index, Center for Epidemiological Studies-Depression-Child scale, and the Pain Catastrophizing Scale for Children. After participation in the 3-week program, adolescents with POTS demonstrated a significant increase in overall functional ability and significant reductions in depression and catastrophizing.

Outcomes of Adolescent-Onset Postural Orthostatic Tachycardia Syndrome

OBJECTIVES

To determine the clinical course of adolescent-onset postural orthostatic tachycardia syndrome (POTS) and to assess health-related quality of life, 2-10 years after diagnosis.

STUDY DESIGN

Pediatric patients, 13-18 years of age, diagnosed with POTS at Mayo Clinic, Rochester, from 2003 to 2010 were mailed a questionnaire if they were at least 18 years of age at the time of the mailing. The primary outcome measures were norm-based, age- and sex-adjusted, 36-Item Short Form Health Survey physical composite score and mental composite score.

RESULTS

The survey was mailed to 502 patients with a response rate of 34% (n = 172). The mean duration from diagnosis to survey completion was 5.4 (SD, 1.9) years; the mean age of the respondents at the time of the survey was 21.8 (2.2) years. The responders were predominantly females (84% vs 68% of nonresponders; P < .001). Only 33 (19%) respondents reported complete resolution of symptoms, and an additional 51% reported persistent but improved symptoms, and 28 (16%) had only intermittent symptoms. The majority (71%) consider their health at least "good." The mean physical composite score was significantly lower than the population norm (mean [SD], 36.6 [15.8] vs 50; P < .001), however, the corresponding mean mental composite score was normal (50.1 [11.2]).

CONCLUSIONS

Overall, 86% of adolescents with POTS report resolved, improved, or just intermittent symptoms, when assessed via questionnaire at an average of 5 years after initial treatment. Patients with persistent symptoms have more physical than mental health concerns.

Dizziness and Orthostatic Intolerance In Pediatric Headache Patients

Children and adolescents with headaches commonly complain of dizziness that creates significant distress among the patients and their families. Dizziness is largely due to either orthostatic intolerance or vertigo; this distinction is the initial step in the evaluation of a child with co-occurrence of headaches and dizziness. Vertiginous symptoms are most commonly due to vestibular migraine or benign positional vertigo. This review would focus its attention on the diagnosis, evaluation, and management of orthostatic intolerance, specifically postural orthostatic tachycardia syndrome.

Plasma C-type natriuretic peptide as a predictor for therapeutic response to metoprolol in children with postural tachycardia syndrome

POTS is a global public-health disease, but predictor for therapeutic response to metoprolol in children with POTS is lacking. This study was designed to investigate predictive value of plasma C-type natriuretic peptide (CNP) in the therapeutic efficacy of metoprolol on postural tachycardia syndrome (POTS) in children. Totally 34 children with POTS and 27 healthy children were included in the study. The head-up test or head-up tilt test was used to check heart rate and blood pressure from supine to upright in subjects. A double antibody (competitive) sandwich immunoluminometric assay was used to detect plasma CNP. Metoprolol was used to treat children with POTS. The difference in plasma concentrations of CNP between responders and non-responders was compared. An ROC curve was used to analyze plasma CNP to predict efficacy of metoprolol on POTS in children. Plasma CNP in children with POTS was significantly higher than that of healthy children [(51.9 ± 31.4) vs. (25.1 ± 19.1) pg/ml, P <0.001]. Plasma CNP in responders to metoprolol was significantly higher than non-responders [(59.1 ± 33.5) vs. (34.8 ± 16.7) pg/ml, P = 0.037] before treatment. The ROC curve showed that area under the curve was 0.821 (95% CI 0.642–0.999). The cut-off value of plasma CNP > 32.55 pg/ml yielded a sensitivity of 95.8% and specificity of 70% in predicting therapeutic efficacy of metoprolol on POTS children. Plasma CNP might serve as a useful predictor for the therapeutic efficacy of metoprolol on POTS in children.

Assessment of therapeutic biomarkers in the treatment of children with postural tachycardia syndrome and vasovagal syncope

BACKGROUND

Postural tachycardia syndrome and vasovagal syncope are common causes of orthostatic intolerance in children. The supplementation with water, or salt, or midodrine, or β-blocker was applied to children with postural tachycardia syndrome or vasovagal syncope. However, the efficacy of such medication varied and was not satisfied. This review aimed to summarise the current biomarkers in the treatment of the diseases.

DATA SOURCES

Studies were collected from online electronic databases, including OVID Medline, PubMed, ISI Web of Science, and associated references. The main areas assessed in the included studies were clinical improvement, the cure rate, and the individualised treatment for postural tachycardia syndrome and vasovagal syncope in children.

RESULTS

Haemodynamic change during head-up tilt test, and detection of 24-hour urinary sodium excretion, flow-mediated vasodilation, erythrocytic H₂S, and plasma pro-adrenomedullin as biological markers were the new ways that were inexpensive, non-invasive, and easy to test for finding those who would be suitable for a specific drug and treatment.

CONCLUSION

With the help of biomarkers, the therapeutic efficacy was greatly increased for children with postural tachycardia syndrome and vasovagal syncope.

Orthostatic plasma norepinephrine level as a predictor for therapeutic response to metoprolol in children with postural tachycardia syndrome

Background

Postural tachycardia syndrome (POTS) is a heterogeneous disorder that creates challenges for treatment. Beta-blocker was one of the most commonly used drugs, but it is inconsistently effective. The purpose of this study is to explore whether orthostatic plasma norepinephrine level could be an indicator of therapeutic effectiveness of metoprolol for POTS in children.

Methods

Twenty-seven children with POTS were enrolled in our study. They received metoprolol treatment, and their orthostatic plasma norepinephrine levels were measured by high-performance liquid chromatography method. Three months after rmetoprolol treatment, 25 patients were followed up. A receiver-operating characteristic (ROC) curve was used to explore the predictive value of orthostatic plasma norepinephrine level.

Results

The symptom severity and increment of heat rate from supine position to upright of patients positively correlated with their orthostatic plasma norepinephrine level (r = 0.599, P < 0.001; r = 0.633, P <0.001, respectively). Orthostatic plasma norepinephrine level in responders to metoprolol was significantly higher than that of nonresponders (P = 0.028). A ROC curve on the predictive value of orthostatic plasma norepinephrine level showed that the area under the curve was 0.785. Using a cutoff value for orthostatic plasma norepinephrine level of 3.59 pg/ml yielded both sensitivity (76.9%) and specificity (91.7%) in predicting the efficacy of metoprolol therapy for POTS.

Conclusion

Orthostatic plasma norepinephrine level of > 3.59 pg/ml was an indicator of the effectiveness of metoprolol therapy for POTS in children and adolescents.

Usefulness of plasma copeptin as a biomarker to predict the therapeutic effectiveness of metoprolol for postural tachycardia syndrome in children

Metoprolol is clinically used to treat postural tachycardia syndrome (POTS) in children, but its effectiveness is unsatisfactory. Biomarkers to predict therapeutic efficacy are needed. We aimed to explore changes in the plasma copeptin level for assessing the therapeutic efficacy of metoprolol for POTS in children. We included 49 children with POTS and 25 healthy children as controls. Patients received metoprolol for 1.5 to 3 months. The plasma copeptin level was measured by sandwich immunoluminometric assay. The area under the receiver operating characteristic curve was used to explore the predictive value of the plasma copeptin level. The baseline plasma copeptin level was higher in children with POTS than controls (10.524 ± 2.016 vs 8.750 ± 1.419 pmol/L, p <0.001) and was lower for responders than nonresponders to metoprolol (9.377 ± 1.411 vs 12.054 ± 1.662 pmol/L, p = 0.003). The area under the receiver operating characteristic curve was 0.889 (95% confidence interval 0.799 to 0.980). With a baseline plasma copeptin level of 10.225 pmol/L as a cutoff, the sensitivity was 90.5% and specificity 78.6% in predicting the efficacy of metoprolol in children with POTS. In conclusion, the baseline plasma copeptin level can be used as a biomarker to predict the therapeutic effectiveness of metoprolol in children with POTS.

Neuronal and hormonal perturbations in postural tachycardia syndrome

The Postural Tachycardia Syndrome (POTS) is the most common disorder seen in autonomic clinics. Cardinal hemodynamic feature of this chronic and debilitating disorder of orthostatic tolerance is an exaggerated orthostatic tachycardia (≥30 bpm increase in HR with standing) in the absence of orthostatic hypotension. There are multiple pathophysiological mechanisms that underlie POTS. Some patients with POTS have evidence of elevated sympathoneural tone. This hyperadrenergic state is likely a driver of the excessive orthostatic tachycardia. Another common pathophysiological mechanism in POTS is a hypovolemic state. Many POTS patients with a hypovolemic state have been found to have a perturbed renin-angiotensin-aldosterone profile. These include inappropriately low plasma renin activity and aldosterone levels with resultant inadequate renal sodium retention. Some POTS patients have also been found to have elevated plasma angiotensin II (Ang-II) levels, with some studies suggesting problems with decreased angiotensin converting enzyme 2 activity and decreased Ang-II degradation. An understanding of these pathophysiological mechanisms in POTS may lead to more rational treatment approaches that derive from these pathophysiological mechanisms.

Adolescent fatigue, POTS, and recovery: a guide for clinicians

Many teenagers who struggle with chronic fatigue have symptoms suggestive of autonomic dysfunction that may include lightheadedness, headaches, palpitations, nausea, and abdominal pain. Inadequate sleep habits and psychological conditions can contribute to fatigue, as can concurrent medical conditions. One type of autonomic dysfunction, postural orthostatic tachycardia syndrome, is increasingly being identified in adolescents with its constellation of fatigue, orthostatic intolerance, and excessive postural tachycardia (more than 40 beats/min). A family-based approach to care with support from a multidisciplinary team can diagnose, treat, educate, and encourage patients. Full recovery is possible with multi-faceted treatment. The daily treatment plan should consist of increased fluid and salt intake, aerobic exercise, and regular sleep and meal schedules; some medications can be helpful. Psychological support is critical and often includes biobehavioral strategies and cognitive-behavioral therapy to help with symptom management. More intensive recovery plans can be implemented when necessary.

A teenage fainter (dizziness, syncope, postural orthostatic tachycardia syndrome)

This article informs the general pediatrician about the diagnosis, evaluation, and treatment of teenage patients with presyncope and loss of consciousness. The focus is on distinguishing noncardiac fainting from life-threatening syncope. Current treatment strategies of vasovagal syncope and postural orthostatic tachycardia syndrome are also outlined.

A double-blind placebo-controlled cross-over study of the vascular effects of midodrine in neuropathic compared with hyperadrenergic postural tachycardia syndrome

POTS (postural tachycardia syndrome) is a chronic form of OI (orthostatic intolerance). Neuropathic POTS is characterized by decreased adrenergic vasoconstriction, whereas hyperadrenergic POTS exhibits increased adrenergic vasoconstriction. We hypothesized that midodrine, an α1-adrenergic receptor agonist, would increase CVR (calf vascular resistance), decrease C(v) (calf venous capacitance) and decrease orthostatic tachycardia in neuropathic POTS, but not alter haemodynamics in hyperadrenergic POTS. A total of 20 POTS patients (12 neuropathic and eight hyperadrenergic), ages 12-20 years, participated in this randomized placebo-controlled double-blind cross-over study. Of these subjects, 15 were female. POTS subjects received 2 weeks of treatment with midodrine or placebo, with increased dosing from 2.5 to 10 mg three times daily. Following a 7-day drug-washout period, subjects received the cross-over treatment. HR (heart rate), MAP (mean arterial pressure), Q(calf) (calf blood flow) and CVR were measured supine and during 35° HUT (head-up tilt). C(v) was measured supine. In neuropathic POTS, midodrine decreased supine HR, Q(calf) and C(v), while increasing MAP and CVR compared with placebo. During HUT, in neuropathic POTS, midodrine decreased HR, Q(calf) and C(v), while increasing MAP and CVR. In hyperadrenergic POTS, placebo and midodrine both decreased upright HR and increased supine CVR. Placebo also increased supine C(v), compared with midodrine in hyperadrenergic POTS. Therefore midodrine improved postural tachycardia in neuropathic POTS by increasing CVR and decreasing Q(calf) and C(v), whereas these effects were not seen in hyperadrenergic POTS patients who experienced a placebo effect. This suggests that midodrine is probably an effective treatment for neuropathic POTS, but not for hyperadrenergic POTS.

Orthostatic intolerance without postural tachycardia: how much dysautonomia?

BACKGROUND

Chronic symptoms of orthostatic intolerance occur in postural tachycardia syndrome (POTS) and patients with orthostatic intolerance (OI) without tachycardia. We recently reported that deconditioning is almost universal in both patient groups. In this study, we focussed on the question of how much dysautonomia, besides orthostatic tachycardia, is there in POTS vs. OI, and how the two groups compare in regards to clinical, autonomic, laboratory, and exercise variables.

METHODS

We retrospectively studied all patients referred for orthostatic intolerance at Mayo Clinic between January 2006 and June 2011, who underwent standardized autonomic and exercise testing.

RESULTS

Eighty-four POTS and 100 OI fulfilled inclusion criteria, 89 % were females. The mean age was 25 and 32 years, respectively. Clinical presentation, autonomic parameters, laboratory findings, and degree of deconditioning were overall similar between the two groups, except for the excessive orthostatic heart rate (HR) rise and mild vasomotor findings observed in POTS but not in OI (slightly larger Valsalva ratio and incomplete blood pressure recovery during Valsalva). Both groups responded poorly to various medications. Severely deconditioned patients were similar to non-deconditioned patients, except for 24 h urine volume (1,555 vs. 2,417 ml), sweat loss on thermoregulatory sweat test (1.5 vs. 0.5 %), and few respiratory parameters during exercise, which are likely clinically insignificant.

CONCLUSION

Though similar in clinical presentation, POTS and OI are different entities with greater, albeit still mild, dysautonomia in POTS. The clinical and pathophysiological relevance of minimal dysautonomia in the absence of orthostatic tachycardia as seen in OI remain uncertain.

Diagnosis and management of postural orthostatic tachycardia syndrome: A brief review

Postural orthostatic tachycardia syndrome (POTS) has been recognized since at least 1940. A review of the literature identifies differences in the definition for this condition and wide variations in treatment and outcomes. This syndrome appears to describe a group of conditions with differing pathophysiology, which requires treatment tailored to the true underlying disorder. Patients need to be fully evaluated to guide treatment. Further research is required to effectively classify the range of underlying pathophysiology that can produce this syndrome and to guide optimal management.

Twenty-four-hour urinary sodium excretion and postural orthostatic tachycardia syndrome

OBJECTIVE

To investigate whether 24-hour urinary sodium excretion could be an indicator of the effectiveness of salt supplementation in children with postural orthostatic tachycardia syndrome (POTS).

STUDY DESIGN

The patient group comprised 30 children with POTS, and the control group comprised 10 healthy children. Serum sodium and 24-hour urinary sodium excretion were measured in all children, and the relationship between 24-hour urinary sodium and symptom severity was analyzed in the 30 patients. At 1 month after initiation of salt supplementation, the receiver operating characteristic curve was used to explore the probability of correctly discriminating responders to salt supplementation from nonresponders using 24-hour urinary sodium excretion as an indicator.

RESULTS

Patients with POTS had lower 24-hour urinary sodium excretion than controls (P = .022). Symptom severity was negatively correlated with 24-hour urinary sodium excretion (OR, -0.754; P = .000). The receiver operating characteristic curve demonstrated a sensitivity of 76.9% and specificity of 93% for correct prediction of responders and nonresponders to salt supplementation when a 24-hour urinary sodium excretion of 124 mmol/24 hours was used as the cutoff value.

CONCLUSION

Our results indicate that 24-hour sodium excretion of <124 mmol/24 hours is an indicator of the effectiveness of salt supplementation in children and adolescents with POTS.

Pediatric autonomic testing: retrospective review of a large series

OBJECTIVE. To describe the reasons for referral, autonomic diagnoses, test results, and patient management in a large pediatric population referred for testing for an autonomic disorder. DESIGN. The authors reviewed autonomic testing data and medical records for patients aged 18 years and younger who underwent testing between 1993 and 2007 and who had adequate clinical data. Relevance of test results to clinical symptoms was ranked on a 3-point scale. Treatments were noted and their benefit ranked on a 5-point scale. RESULTS. Among 142 pediatric patients identified, postural tachycardia syndrome was most common (71%) while orthostatic hypotension was rare (5%). Testing provided relevant information regarding the patient's symptoms in 88% of the cases. Beta-blockers were the most commonly prescribed medication (59%); 73% improved. CONCLUSIONS. Postural tachycardia syndrome was common in this large pediatric population, whereas orthostatic hypotension was infrequent. The symptomatic improvement in the majority bears an unclear relationship to treatment. Prospective studies are needed.

Functional disability in adolescents with orthostatic intolerance and chronic pain

A retrospective review identified 99 adolescents (79% female) referred to a tertiary care center to evaluate the relationship between symptoms of orthostatic intolerance and chronic pain. Regression analysis indicated that functional disability was strongly associated with pain intensity (P < .001) and depression (P = .024). The association between functional disability and number of symptoms of orthostatic intolerance trended toward significance (P = .057). Meeting a threshold heart rate increment of 30 beats per minute on head-up tilt was not associated with functional disability (P = .188). Separate regression analysis of female patients showed similar results to the full sample but with a stronger relationship between depression and functional disability and a weaker relationship between heart increment and functional disability. In this sample of adolescents with symptoms of orthostatic intolerance and chronic pain, pain intensity and depression were associated with functional status, but postural tachycardia was not. Further research is needed to clarify potential gender differences.

Orthostatic intolerance and the headache patient

Orthostatic intolerance (OI) refers to a group of clinical conditions, including postural orthostatic tachycardia syndrome (POTS) and neurally mediated hypotension (NMH), in which symptoms worsen with upright posture and are ameliorated by recumbence. The main symptoms of chronic orthostatic intolerance syndromes include light-headedness, syncope or near syncope, blurring of vision, headaches, problems with short-term memory and concentration, fatigue, intolerance of low impact exercise, palpitations, chest pain, diaphoresis, tremulousness, dyspnea or air hunger, nausea, and vomiting. This review discusses what is known about the pathophysiology of this disorder, potential treatments, and understanding its role in the patient with chronic headache pain.

Postural orthostatic tachycardia syndrome: a clinical review

Postural orthostatic tachycardia syndrome was defined in adult patients as an increase >30 beats per minute in heart rate of a symptomatic patient when moving from supine to upright position. Clinical signs may include postural tachycardia, headache, abdominal discomfort, dizziness/presyncope, nausea, and fatigue. The most common adolescent presentation involves teenagers within 1-3 years of their growth spurt who, after a period of inactivity from illness or injury, cannot return to normal activity levels because of symptoms induced by upright posture. Postural orthostatic tachycardia syndrome is complex and likely has numerous, concurrent pathophysiologic etiologies, presenting along a wide spectrum of potential symptoms. Nonpharmacologic treatment includes (1) increasing aerobic exercise, (2) lower-extremity strengthening, (3) increasing fluid/salt intake, (4) psychophysiologic training for management of pain/anxiety, and (5) family education. Pharmacologic treatment is recommended on a case-by-case basis, and can include beta-blocking agents to blunt orthostatic increases in heart rate, alpha-adrenergic agents to increase peripheral vascular resistance, mineralocorticoid agents to increase blood volume, and serotonin reuptake inhibitors. An interdisciplinary research approach may determine mechanistic root causes of symptoms, and is investigating novel management plans for affected patients.