Postural Tachycardia Research Articles

Cardiovascular Autonomic Regulation, ETCO2 and the Heart Rate Response to the Tilt Table Test in Patients with Orthostatic Intolerance.

Chronic orthostatic intolerance (COI) is defined by changes in heart rate (HR), blood pressure (BP), respiration, symptoms of cerebral hypoperfusion and sympathetic overactivation. Postural tachycardia syndrome (POTS) is the most common form of COI in young adults and is defined by an orthostatic increase in heart rate (HR) of ≥ 30bpm in the absence of orthostatic hypotension. However, some patients referred for evaluation of COI symptoms do not meet the orthostatic HR response criterion of POTS despite debilitating symptoms. Such patients are ill defined, posing diagnostic and therapeutic challenges. This study explored the relationship among cardiovascular autonomic control, the orthostatic HR response, EtCO2 and the severity of orthostatic symptoms and fatigue in patients referred for evaluation of COI. Patients (N = 108) performed standardized testing protocol of the Autonomic Reflex Screen and completed the Composite Autonomic Symptom Score (COMPASS-31) and the Fatigue Severity Scale (FSS). Greater severity of COI was associated with younger age, larger phase IV amplitude in the Valsalva maneuver and lower adrenal baroreflex sensitivity. Greater fatigue severity was associated with a larger reduction in ETCO2 during 10min of head-up tilt (HUT) and reduced low-frequency (LF) power of heart rate variability. This study suggests that hemodynamic changes associated with the baroreflex response and changes in EtCO2 show a stronger association with the severity of orthostatic symptoms and fatigue than the overall orthostatic HR response in patients with COI.

Multisystemic Presentation of Iliac Venous Compression disease (May-Thurner Syndrome) that Improves or Resolve after Intervention: A Single-Center Experience of a 189-Patient Analysis of Nonthrombotic Compression Intervention and Outcome

We present analysis of about 200 patient out of 500+ nonthrombotic iliac venous compression interventions to demonstrate that patients symptoms are far ranging that includes cardiovascular (postural orthostatic tachycardia syndrome), pulmonary, gastrointestinal, genitourinary, gynecological, orthopedic, and neurologic manifestations that improve or resolve after intervention. Awareness and inclusion of multisystemic symptoms in evaluating May-Thurner Syndrome patients is paramount in understanding venous diseases.

Prevalence of joint hypermobility, postural orthostatic tachycardia syndrome (POTS), and orthostatic hypotension in school-children.

Children with joint hypermobility, postural orthostatic tachycardia syndrome, and orthostatic hypotension report autonomic symptoms such as dizziness, nausea, headaches, and palpitations. It is unclear if there is a pathophysiological link between connective tissue disorders and autonomic symptoms. There is no published data on the prevalence of disorder at the community level. To assess the prevalence of joint hypermobility, orthostatic hypotension, and postural or thostatic tachycardia syndrome in children. To determine the relationship bet ween joint hypermobility, orthostatic hypotension, and postural orthostatic tachycardia syndrome. Participants aged 10 to 18 years were selected from public schools in three Colombian cities. The surveys included historical questions on the incidence of dizziness, nausea, headache, tremor, blurred vision, vertigo, anxiety, near syncope and syncope, sweating, palpitations triggered by standing in the two months prior to the investigation. Each of these signs and symptoms was also assessed during the recumbency (10 minutes) and standing (2, 5 and 10 minutes) phases of the investigation. HR and BP measurements were obtained at the same intervals. Joint mobility was measured with a mechanical goniometer and assessed with the Beighton score. Prevalence of joint hyperlaxity: 87 of 306 (28.4%). Prevalence of orthostatic hypotension: 5 of 306 (1.6%). Prevalen ce of postural orthostatic tachycardia syndrome: 6 of 306 (2.0%). Of 87 children with joint hyperlaxi ty, only 1 child had joint hyperlaxity at the same time as postural hypotension (1.2%) (p = 0.6735), and 1 child had joint hyperlaxity and postural orthostatic tachycardia syndrome simultaneously (1.2%) (p = 0.5188). Children with joint hyperlaxity did not have a higher prevalence of postural orthostatic tachycardia syndrome and orthostatic hypotension. It seems unlikely that con nective tissue disorders are responsible for most cases of postural orthostatic tachycardia syndrome and orthostatic hypotension in the community. Of note, the pathophysiology of postural orthostatic tachycardia syndrome and orthostatic hypotension requires further investigation.

Postural orthostatic tachycardia syndrome in children and adolescents

Background: Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous disorder in children and adolescents. Recently, there have been some data concerning the prevalence of POTS in adults. However, current studies on POTS in children and adolescents are rare. Thus, many young patients with POTS are misdiagnosed with migraine or other diseases.Current Concepts: The diagnosis and treatment of POTS differ between pediatric and adult patients. POTS in children and adolescents is diagnosed with chronic symptoms of orthostatic intolerance, such as a heart rate rise of 40 beat per minute (bpm) or a heart rate exceeding 130 bpm without orthostatic hypotension. There are three major POTS categories: hypovolemic POTS, neuropathic POTS, and hyperadrenergic POTS. These categories are distinguished by their major mechanisms. The different subtypes of POTS in children and adolescents have their own clinical characteristics and laboratory findings.Discussion and Conclusion: Treatment of POTS in children and adolescents should always include lifestyle changes, nutritional adjustments, exercise, and drugs depending on the different subtypes of POTS.

Transcutaneous vagus nerve stimulation attenuates autoantibody-mediated cardiovagal dysfunction and inflammation in a rabbit model of postural tachycardia syndrome.

Previous studies demonstrated M2 muscarinic acetylcholine receptor-activating autoantibodies (M2R-AAb) were present in some patients with postural tachycardia syndrome (POTS). This study examines how these autoantibodies might contribute to the pathophysiology of POTS, and whether low-level tragus stimulation (LLTS) can ameliorate autoantibody-mediated autonomic dysregulation in the rabbit. Five New Zealand white rabbits were immunized with a M2R second extracellular loop peptide to produce cholinomimetic M2R-AAb. Tilt test and infusion studies were performed on conscious rabbits before immunization, 6weeks after immunization, and 8weeks after immunization with 2-week daily LLTS treatment. Each rabbit served as its own control. Compared to preimmune state, an enhanced heart rate increase and decreased parasympathetic activity upon tilting were observed in immunized rabbits. Furthermore, these rabbits demonstrated an attenuated heart rate-slowing response to infusion of the M2R orthosteric agonist arecaidine propargyl ester (APE), suggesting an inhibitory allosteric effect of M2R-AAb. There was also a significant increase in serum inflammatory cytokines in immunized rabbits. LLTS treatment suppressed the postural tachycardia, improved the sympathovagal balance with increased acetylcholine secretion, reduced the levels of inflammatory cytokines, and reversed the attenuated heart rate response to APE in immunized rabbits. No suppression of M2R-AAb expression by LLTS was found during this short-term study period. Receptor-modulating activity of M2R-AAb produced in immunized rabbits was confirmed with in vitro bioassay. Autoantibody inhibition of cholinergic ligand activity may be involved in the development of cardiovagal dysfunction and inflammation associated with POTS, both of which can be improved by vagal stimulation.

Gluten-free diet in postural orthostatic tachycardia syndrome (POTS).

Postural orthostatic tachycardia syndrome (POTS) is a chronic disorder of the autonomic nervous system that is associated with orthostatic intolerance (OI) and gastrointestinal (GI) symptoms. We aimed to determine if a gluten-free diet (GFD) may be an effective treatment in patients with POTS. Patients with confirmed POTS and without celiac disease who followed GFD for 4 weeks retrospectively completed pre- and post- GFD COMPASS-31 questionnaires. Paired-samples t-tests were conducted to compare COMPASS-31 scores before and after adopting GFD. All 20 patients (all females, age 16-62 years (mean age 33)), had POTS symptoms for 1-30 years (mean 10.8, SD = 10.23 years). Eleven patients had co-morbid mast cell activation syndrome, and 8 had hypermobile Ehlers-Danlos syndrome. Pre-GFD COMPASS-31 scores (mean 57.8) were significantly higher than post-GFD scores (mean 38.2, t(19) = -8.92, p < 0.00001), with the largest improvement noted in the OI (p < 0.00001), vasomotor, (p = 0.0034), and GI (p = 0.0004) domains and with a mean reduction in total COMPASS-31 score by 33.9% after implementing GFD. All patients reported improved symptoms on GFD with mean self-assessed improvement of 50.5% (range 10-99%). GFD may be effective in reducing the symptom burden in patients with POTS, particularly in the OI, vasomotor, and GI symptom domains. Large prospective studies are necessary to confirm whether GFD is an effective long-term treatment option for patients.

Heart rate variability as a marker of cardiovascular dysautonomia in post-COVID-19 syndrome using artificial intelligence

IntroductionCardiovascular dysautonomia comprising postural orthostatic tachycardia syndrome (POTS) and orthostatic hypotension (OH) is one of the presentations in COVID-19 recovered subjects. We aim to determine the prevalence of cardiovascular dysautonomia in post COVID-19 patients and to evaluate an Artificial Intelligence (AI) model to identify time domain heart rate variability (HRV) measures most suitable for short term ECG in these subjects. MethodsThis observational study enrolled 92 recently COVID-19 recovered subjects who underwent measurement of heart rate and blood pressure response to standing up from supine position and a 12-lead ECG recording for 60 s period during supine paced breathing. Using feature extraction, ECG features including those of HRV (RMSSD and SDNN) were obtained. An AI model was constructed with ShAP AI interpretability to determine time domain HRV features representing post COVID-19 recovered state. In addition, 120 healthy volunteers were enrolled as controls. ResultsCardiovascular dysautonomia was present in 15.21% (OH:13.04%; POTS:2.17%). Patients with OH had significantly lower HRV and higher inflammatory markers. HRV (RMSSD) was significantly lower in post COVID-19 patients compared to healthy controls (13.9 ± 11.8 ms vs 19.9 ± 19.5 ms; P = 0.01) with inverse correlation between HRV and inflammatory markers. Multiple perceptron was best performing AI model with HRV(RMSSD) being the top time domain HRV feature distinguishing between COVID-19 recovered patients and healthy controls. ConclusionPresent study showed that cardiovascular dysautonomia is common in COVID-19 recovered subjects with a significantly lower HRV compared to healthy controls. The AI model was able to distinguish between COVID-19 recovered patients and healthy controls.

Arterial Baroreceptor Physiology: Differences Between Normal Subjects and Pediatric Patients with Postural Tachycardia and Neurocardiogenic Syncope

The arterial baroreceptor reflex in children and adolescents has not been well studied in the current literature with a lack of agreed upon normal values, particularly in postural orthostatic tachycardia syndrome (POTS) or neurocardiogenic syncope (NCS). We used the sequence method and head-up tilt test (HUTT) to evaluate baroreceptor function in 3 phases: baseline supine position for 10min, head-up position at 70° for 30min or until syncope, and post-tilt supine reposition for 10min. We measured the number of baroreceptor events, baroreceptor effectiveness index (BEI), and the magnitude of sensitivity of the events at each phase of HUTT. We studied 198 individuals (49 normal subjects, 67 POTS, 82 NCS) with age ranges from 8 to 21years. The data show a statistically significant decrease in slope and BEI in patients with POTS and NCS during the head-up phase, with an increase in activity in the lag 1 and 2 portions of all phases in patients with POTS. This study provides terminology to describe baroreceptor function and identifies the slope and BEI portions of the baroreceptor reflex as the most useful objective measures to differentiate pediatric patients with POTS and NCS from normal subjects.

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

ObjectivesThe 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).MethodsThere 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.ResultsThe 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.ConclusionBaseline QTcd is effective for predicting the effectiveness of metoprolol on pediatric POTS.

Multisystem Involvement in Post-Acute Sequelae of Coronavirus Disease 19.

ObjectiveThe purpose of this study was to describe cerebrovascular, neuropathic, and autonomic features of post‐acute sequelae of coronavirus disease 2019 ((COVID‐19) PASC).MethodsThis retrospective study evaluated consecutive patients with chronic fatigue, brain fog, and orthostatic intolerance consistent with PASC. Controls included patients with postural tachycardia syndrome (POTS) and healthy participants. Analyzed data included surveys and autonomic (Valsalva maneuver, deep breathing, sudomotor, and tilt tests), cerebrovascular (cerebral blood flow velocity [CBFv] monitoring in middle cerebral artery), respiratory (capnography monitoring), and neuropathic (skin biopsies for assessment of small fiber neuropathy) testing and inflammatory/autoimmune markers.ResultsNine patients with PASC were evaluated 0.8 ± 0.3 years after a mild COVID‐19 infection, and were treated as home observations. Autonomic, pain, brain fog, fatigue, and dyspnea surveys were abnormal in PASC and POTS (n = 10), compared with controls (n = 15). Tilt table test reproduced the majority of PASC symptoms. Orthostatic CBFv declined in PASC (−20.0 ± 13.4%) and POTS (−20.3 ± 15.1%), compared with controls (−3.0 ± 7.5%, p = 0.001) and was independent of end‐tidal carbon dioxide in PASC, but caused by hyperventilation in POTS. Reduced orthostatic CBFv in PASC included both subjects without (n = 6) and with (n = 3) orthostatic tachycardia. Dysautonomia was frequent (100% in both PASC and POTS) but was milder in PASC (p = 0.002). PASC and POTS cohorts diverged in frequency of small fiber neuropathy (89% vs 60%) but not in inflammatory markers (67% vs 70%). Supine and orthostatic hypocapnia was observed in PASC.InterpretationPASC following mild COVID‐19 infection is associated with multisystem involvement including: (1) cerebrovascular dysregulation with persistent cerebral arteriolar vasoconstriction; (2) small fiber neuropathy and related dysautonomia; (3) respiratory dysregulation; and (4) chronic inflammation. ANN NEUROL 2022;91:367–379

Clinical Features of Patients Undergoing the Head-Up Tilt Test and Its Safety and Efficacy in Diagnosing Vasovagal Syncope in 4,873 Patients.

Background: The head-up tilt test (HUTT) is a useful diagnostic tool in patients with suspected vasovagal syncope (VVS).Objectives: We aimed to investigate the direct drug-potentiated HUTT in patients with recurrent syncope or precursor syncope and to assess the diagnostic value of the direct drug-potentiated HUTT.Methods: The medical history and direct drug-potentiated HUTT records of patients who complained of syncope or precursor syncope and who visited The Xianyang Central Hospital from January 2016 to December 2020 were retrospectively reviewed.Results: A total of 4,873 patients (age = 43.8 ± 17.6 years; male = 2,064 [42.4%]) were enrolled in our study. Overall, 2,343 (48.1%) showed positive responses as follows: 1,260 (25.9%) with the mixed type, 34 (0.7%) with the cardioinhibitory type, 580 (11.9%) with the vasodepressor type, 179 (3.7%) with postural tachycardia syndrome (POTS), and 290 (6.0%) with orthostatic hypotension (OH). The study showed that prior to syncope or near-syncope symptoms, patients first presented an increase in heart rate (HR), followed by decreases in blood pressure (BP) and HR successively. Among the patients in the syncope group, the sensitivity of the HUTT was 65.9%, which was significantly higher than a sensitivity of 44.8% for patients in the non-syncope group (P < 0.01). The sensitivity of the HUTT was higher for females than males in both the syncope group (52.6% in males and 77.9% in females, P < 0.01) and the non-syncope group (36.5% in males and 50.6% in females, P < 0.01). Within the four age groups (<20, 21–40, 41–60, and >60 years old), the sensitivities were 74.7%, 67.7%, 45.6%, and 31.2%, respectively. And all gender, age and symptom (whether suffered from a syncope or not) significantly affected the positive responses of HUTT. There were two adverse events and no deaths during the HUTT in this study.Conclusion: The direct drug-potentiated HUTT is a safe and highly sensitive tool with which to diagnose VVS. Patients with precursor syncope symptoms without syncope should undergo a HUTT, especially young females presenting with weakness and sweating, which can decrease the probability of a misdiagnosis or a missed diagnosis.

Psychogenic Pseudosyncope: Real or Imaginary? Results from a Case-Control Study in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Patients.

Background and objectives: Orthostatic intolerance (OI) is a clinical condition in which symptoms worsen upon assuming and maintaining upright posture and are ameliorated by recumbency. OI has a high prevalence in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Exact numbers on syncopal spells especially if they are on a weekly or even daily basis are not described. Although not a frequent phenomenon, this symptomatology is of very high burden to the patient if present. To explore whether patients with very frequent (pre)syncope spells diagnosed elsewhere with conversion or psychogenic pseudosyncope (PPS) might have another explanation of their fainting spells than behavioral psychiatric disorders, we performed a case–control study comparing ME/CFS patients with and without PPS spells. Methods and results: We performed a case–control study in 30 ME/CFS patients diagnosed elsewhere with PPS and compared them with 30 control ME/CFS patients without syncopal spells. Cases were gender, age and ME/CFS disease duration matched. Each underwent a tilt test with extracranial Doppler measurements for cerebral blood flow (CBF). ME/CFS cases with PPS had a significant larger CBF reduction at end tilt than controls: 39 (6)% vs. 25 (4)%; (p < 0.0001). Cases had more severe disease compared with controls (chi-square p < 0.01 and had a p = 0.01) for more postural orthostatic tachycardia syndrome in cases compared with controls. PETCO2 end-tilt differed also, but the magnitude of difference was smaller than compared with the CBF reduction: there were no differences in heart rate and blood pressure at either end-tilt testing period. Compared with the test with the stockings off, the mean percentage reduction in cardiac output during the test with compression stockings on was lower, 25 (5) mmHg versus 29 (4) mmHg (p < 0.005). Conclusions: This study demonstrates that in ME/CFS patients suspected of having PPS, or conversion, CBF measurements end-tilt show a large decline compared with a control group of ME/CFS patients. Therefore, hypoperfusion offers an explanation of the orthostatic intolerance and syncopal spells in these patients, where it is clear that origin might not be behavioral or psychogenic, but have a clear somatic pathophysiologic background.

Association of autoantibodies to muscarinic acetylcholine receptors with gastrointestinal symptoms and disease severity in patients with postural orthostatic tachycardia syndrome.

Previous studies have reported a relationship between postural orthostatic tachycardia syndrome (POTS) and positivity for serum autoantibodies against G-protein-coupled receptors (GPCRs). However, the role of these autoantibodies in POTS is unclear. The present retrospective study analyzed the autoimmune etiology of POTS in 24 patients using a head-up tilt test to assess for any correlation between the clinical features of POTS and serum levels of autoantibodies against diverse GPCRs. In total, ten assessment items, including autonomic function tests, were analyzed. Of these, persistent, gastrointestinal symptoms and disease severity showed a significant association with the serum level of anti-muscarinic acetylcholine receptor (mAChRs) antibodies (gastrointestinal symptoms, M1, M2, M5; disease severity, M1, M3, M4, M5) [P <0.05]), while no significant association was found between the clinical features and autoantibodies against adrenergic receptors (α1, α2, β1, β2), angiotensin receptor 1, or endothelin receptor A. The patients were further divided into two groups based on the presence or absence of persistent gastrointestinal symptoms and then were characterized by the ten assessment items and neuropsychological tests, including the Wechsler Adult Intelligence Scale score and Self-Rating Depression Scale score. The results demonstrated a clear difference between the two groups in terms of disease severity, age at onset (older or younger than 20 years), and processing speed index (P <0.05), which were highly consistent with the association between these clinical features and the levels of serum anti-mAChR antibodies, particularly the anti-M5 receptor antibody. These findings suggested that anti-mAChR antibodies may play an important role in a subgroup of POTS patients with persistent gastrointestinal symptoms.

EP News: Case Reports

Data continue to emerge about both the short- and long-term complications associated with severe acute respiratory syndrome coronavirus 2 infection (coronavirus disease 2019 [COVID-19]). Clinics have been created to treat COVID-19 “long haulers” who often report persistent symptoms including those related to autonomic dysfunction that can mimic postural orthostatic tachycardia syndrome (POTS) and inappropriate sinus tachycardia (IST). Desai et al (https://doi.org/10.1016/j.hrcr.2021.11.019) reported the long-term outcomes and management of 11 patients who were diagnosed with COVID-19 infection and autonomic dysfunction.

Coefficient of variation of heart rate and blood pressure in rapid identification of children with suspected orthostatic intolerance

Objective: To investigate the clinical value of coefficient of variation of heart rate and blood pressure in rapid identification of children with suspected orthostatic intolerance(OI). Methods: This was a retrospective study. The medical records of 379 children with OI were collected, who were admitted to the Department of Pediatrics of Qilu Hospital of Shandong University from January 2015 to January 2020. Another 20 out-patient children without syncope or syncope aura were selected as control. According to the results of standing test and head-up tilt test (HUTT), all the patients with OI were divided into the following 4 groups: vasovagal syncope (VVS) group, postural tachycardia syndrome (POTS) group, POTS combined with VVS (POTS+VVS) group and HUTT negative group. Then, coefficient of variation of systolic pressure (SBPCV), coefficient of variation of diastolic pressure (DBPCV) and coefficient of variation of heart rate (HRCV) in standing test and HUTT were calculated. Kruskal-Wallis test was used for comparison among the five groups, and Dunnett's T3 method for comparison between two groups. Paired t test was used to compare the coefficient of variation between supine and erect position and tilt position in each group. The predictive values of HRCV,SBPCV and DBPCV for negative HUTT were evaluated by receiver operating characteristic (ROC) curve. Results: Among the 379 children, there were 79 in HUTT negative group, 208 in VVS group, 52 in POTS group, and 40 in POTS+VVS group. The SBPCV of supine-erect position of the control group, HUTT negative group, VVS group, POTS group, POTS+VVS group were (3.8±1.0)%, (5.3±2.2)%, (6.6±3.4)%, (5.9±3.6)%, (6.9±2.8)%, respectively. Similarly, the SBPCV of supine, erect and head-up tilt position were (4.5±0.8)%, (6.0±1.9)%, (7.1±2.6)%, (6.0±2.1)%, (7.3±2.5)%; the DBPCV of supine-erect position were (7.3±1.2)%, (9.1±3.7)%, (9.1±4.9)%, (9.1±4.8)%, (11.6±4.6)%; the DBPCV of supine, erect and tilt position were (7.4±1.1)%, (9.4±2.9)%, (10.1±3.8)%, (9.2±3.3)%, (11.0±4.7)%; the HRCV of supine-erect position were (7.6±2.6)%, (12.9±3.7)%, (16.2±4.3)%, (21.2±5.9)%, (24.9±5.3)%; and the HRCV of supine, erect and tilt position were (8.1±1.6)%, (10.1±2.7)%, (14.1±4.3)%, (15.6±3.7)%, (18.9±4.0)%, respectively. All the indexes showed significant differences among the five groups (χ2=21.91, 25.47, 19.82, 14.65, 104.52, 92.51, all P<0.05). ROC curve analysis showed that when the SBPCV and HRCV of supine-erect position reached 4.4% and 10.5%, the area under the curve of ROC were 0.713 and 0.877, the sensitivity of predicting negative HUTT were 58.2% and 78.5%, and the specificity were 80.0% and 95.0%, respectively. Conclusions: Coefficient of variation of heart rate and blood pressure may serve as potential diagnostic indexes in evaluating autonomic function of OI patients. SBPCV ≥ 4.4% or HRCV ≥ 10.5% of supine-erect position could be an indication of HUTT.

The Treatment of Postural Orthostatic Tachycardia Syndrome in Adolescents in an Interdisciplinary Treatment Program: Preliminary Outcomes

Importance: Estimates suggest that 1% of all teens struggle with Postural Orthostatic Tachycardia Syndrome. It can be a devastating condition for the adolescents who do not respond to the currently available pharmacologic and non-pharmacologic interventions. Preliminary data suggests that intensive interdisciplinary treatment may provide an effective intervention that can return these youth to normal functioning including full-time attendance at school, as well as reduce orthostatic symptoms, and psychological distress. Objective: To determine the effectiveness and durability of a 3-week interdisciplinary treatment in adolescents with Postural Orthostatic Tachycardia Syndrome in improving orthostatic symptoms, functioning, and psychological distress. Design: Patients diagnosed with Postural Tachycardia Syndrome admitted to an interdisciplinary treatment program were assessed at admission, discharge and 3-month follow-up to determine presence and severity of orthostatic symptoms, as well as functional status including return to school, and depression. Setting: An intensive interdisciplinary treatment program in a tertiary hospital outpatient setting. Participants: Forty-five adolescents ages 12-18 with confirmed diagnoses of Postural Tachycardia Syndrome referred to a tertiary medical center for interdisciplinary treatment. Intervention: A 3-week intensive outpatient interdisciplinary rehabilitation program with significant parental involvement based on a cognitive-behavioral model. Main Outcome and Measure(s): Self-reported orthostatic symptoms were assessed with the Compass 31; level of functioning was assessed with the Functional Disability Index, depressive symptoms were assessed with the Center for Epidemiological Studies-Depression for Children, and self-reported school attendance was assessed. Results: Significant improvements were observed and maintained at the end of treatment and at 3-month follow-up on measures of orthostatic symptoms, physical functioning, and psychological distress. At admission, 32% of patients had completed high school or were attending school full-time. At 3-month follow-up, 90% were either attending school full-time or had completed their schooling. Keywords: Postural Orthostatic Tachycardia Syndrome, POTS, interdisciplinary treatment, adolescents.

The gastrointestinal effects amongst Ehlers-Danlos syndrome, mast cell activation syndrome and postural orthostatic tachycardia syndrome

&lt;abstract&gt; &lt;p&gt;Ehlers-Danlos syndrome (EDS), mast cell activation syndrome, and postural orthostatic tachycardia syndrome are a triad of comorbid conditions that can occur simultaneously in many patients. Specifically, Ehlers-Danlos syndrome is a group of inherited connective tissue disorders that weakens the connective tissue and causes easy bruising. Mast cell activation syndrome (MCAS) is a condition in the connective tissue of vascularized organs that causes recurrent episodes of anaphylactic symptoms. The irregular activation of mast cells may contribute to immunological manifestations in EDS patients. Postural orthostatic tachycardia syndrome (POTS) is an autonomic nervous system disorder characterized by orthostatic intolerance. Review of the literature suggests an overlap of gastrointestinal (GI) symptoms such as nausea and abdominal pain, hernias, perforations, and more. Thus, this paper will delineate each condition's distinct gastrointestinal symptoms and explore similar gastrointestinal relationships among these conditions.&lt;/p&gt; &lt;/abstract&gt;

Postural Orthostatic Tachycardia Syndrome is Associated With Low Health-related Quality of Life and High Levels of Pain

Low health-related quality of life (HrQOL) is associated with poor outcomes in several populations. Postural orthostatic tachycardia syndrome (POTS) is a debilitating condition with significant impact on affected individuals.

Salt supplementation in the management of orthostatic intolerance: Vasovagal syncope and postural orthostatic tachycardia syndrome.

Salt supplementation is a common non-pharmacological approach to the management of recurrent orthostatic syncope or presyncope, particularly for patients with vasovagal syncope (VVS) or postural orthostatic tachycardia syndrome (POTS), although there is limited consensus on the optimal dosage, formulation and duration of treatment. Accordingly, we reviewed the evidence for the use of salt supplementation to reduce susceptibility to syncope or presyncope in patients with VVS and POTS. We found that short-term (~3months) salt supplementation improves susceptibility to VVS and associated symptoms, with little effect on supine blood pressure. In patients with VVS, salt supplementation is associated with increases in plasma volume, and an increase in the time taken to provoke a syncopal event during orthostatic tolerance testing, with smaller orthostatic heart rate increases, enhanced peripheral vascular responses to orthostatic stress, and improved cerebral autoregulation. Responses were most pronounced in those with a baseline sodium excretion <170mmol/day. Salt supplementation also improved symptoms, plasma volume, and orthostatic responses in patients with POTS. Salt supplementation should be considered for individuals with recurrent and troublesome episodes of VVS or POTS without cardiovascular comorbidities, particularly if their typical urinary sodium excretion is low, and their supine blood pressure is not elevated. The efficacy of the response, in terms of the improvement in subjective and objective markers of orthostatic intolerance, and any potential deleterious effect on supine blood pressure, should be routinely monitored in individuals on high salt regimes.

The Relationship of Pregnancy to Postural Orthostatic Tachycardia Syndrome (POTS) Onset and Symptomatology

Postural orthostatic tachycardia syndrome (POTS) is a dysautonomia typically affecting young women with a cycle of exacerbations and remissions. Symptoms include orthostatic intolerance, palpitations, presyncope, syncope and chest pain. Variation in POTS symptoms throughout pregnancy is not well known.