Postural Tachycardia Syndrome Patients Research Articles

Involuntary emotional expression disorder in postural tachycardia syndrome.

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

Brain fog in postural tachycardia syndrome: An objective cerebral blood flow and neurocognitive analysis.

BackgroundIt remains unclear whether brain fog is related to impaired cerebral blood flow (CBF) in postural tachycardia syndrome (POTS) patients.MethodsWe assessed CBF in the posterior cerebral artery (PCA) using transcranial Doppler with visual stimuli in 11 POTS and 8 healthy subjects in the seated position, followed by neurocognitive testing.ResultsCBF parameters were similar between the two groups. POTS patients demonstrated significantly longer latency in delayed match to sample response time and greater errors in attention switching task.ConclusionsImpaired short‐term memory and alertness may underlie the symptom of brain fog in POTS patients, despite normal CBF.

When Sinus Tachycardia Becomes Too Much: Negative Effects of Excessive Upright Tachycardia on Cardiac Output in Vasovagal Syncope, Postural Tachycardia Syndrome, and Inappropriate Sinus Tachycardia.

Upright posture reduces venous return, stroke volume, and cardiac output (CO) while causing reflex sinus rate (heart rate [HR]) increase. Yet, in inappropriate sinus tachycardia (IST), postural tachycardia syndrome (POTS), and vasovagal syncope (VVS), symptomatic excessive HR occurs. We hypothesized that CO reaches maximum as function of HR in all. We recruited 12 healthy controls, 9 IST, 30 VVS, and 30 POTS patients (13-23years) selected randomly by disorder not by HR, each fulfilled appropriate diagnostic criteria. Subjects were instrumented for electrocardiography, beat-to-beat blood pressure, respiratory rate, CO-Modelflow algorithm, and central blood volume from impedance cardiography; 10-minute data were collected supine; subjects were tilted head-up for ≤10 minutes. We computed phase differences, ΔΦ, between fluctuations of HR (ΔHR) and CO (ΔCO) tabulating data when phases were synchronized, determined by a squared nonlinear phase synchronization index >0.5, describing extent/validity of CO/HR coupling. We graphed results supine, 1-minute post-tilt-up, mid-tilt, and pre-tilt-down using polar coordinates (HR-radius, ΔΦ-angle) plotting cos(ΔΦ) versus HR to determine if transition HR exists at which in-phase shifts to antiphase above which CO decreases when HR further increases. At baseline HR, diastolic and mean arterial pressures in IST and POTS were higher versus controls. Upright HR increased most in POTS then IST and VVS, with diverse changes in CO, SVR, and central blood volume. Each patient grouping was separately and collectively analyzed for HR change showing transition from in-phase to anti-phase (ΔΦ) as HR increased: HRtransition=115±6 (IST), 123±8 (POTS), 124±7 (VVS), P=ns. Controls never reached transitional HR. Excessive HR independently and equivalently reduces upright CO, in IST, POTS, and VVS.

Postural Taşikardi Sendromu Hastalarında Kalp Hızı Değişkenliğinin Değerlendirilmesi

Purpose: Postural tachycardia syndrome (POTS) is a disease associated with dysautonomia. Disruption of the sympathetic/parasympathetic balance is the main pathophysiological mechanism. The aim of this study was to evaluate this imbalance with mean heart rate and spectral parameters of heart rate variability measured by ambulatory rhythm monitoring. Patients and methods: One hundred and ninety-three patients with negative HUT test results and without any chronic disease enrolled in the study between 2014 and 2018. POTS was diagnosed when a 30 beats per minute increase at heart rate compared to baseline was observed during the first 10 minutes of the 70 ͦ tilt test. Patients were divided into two groups as POTS (n=27) and non POTS (n=166). Results: POTS was diagnosed in 27 (%13.9) of the 193 patients with negative HUT. Spectral parameters of heart rate variability as SDNN, SDANN, rMSSD and pNN50 values were similar between groups. Average heart rate was significantly higher in POTS patients when compared with non-POTS patients (%80 vs%47.8, p=0.024). Average heart rate above 75 beats per minutes was the only independent predictor for POTS [OR: 4.608 (1.447-14.705), p=0.01]. Conclusion: Evaluation of average heart rate by 24-hour ambulatory rhythm monitoring may be an important parameter in individuals with POTS without structural heart or chronic disease. &nbsp

481 Motility Abnormalities Identified by Wireless Motility Capsule in Postural Orthostatic Tachycardia Syndrome

INTRODUCTION: Gastrointestinal symptoms are common in patients with postural tachycardia syndrome (POTS). Previous studies have reported a wide range of abnormalities, particularly delayed gastric emptying in POTS. Wireless motility capsule (WMC) is a minimally invasive test that allows the evaluation of gastrointestinal physiology. We aimed to investigate the diagnostic yield of WMC in patients with POTS. METHODS: We conducted a retrospective review of all patients at our institution with both formal WMC testing (SmartpillTM) and autonomic testing for evaluation of gastrointestinal and neurological symptoms respectively. Patient demographics and results of respective testing were extracted. We compared transit abnormalities and contraction patterns between patients meeting diagnostic criteria for POTS and those without POTS. Transit abnormality percentages were compared using chi2 testing, and contraction pattern parameters were compared using 2-sample t-testing. RESULTS: A total of 27 women with both WMC and autonomic testing were studied. The mean age was 39.6 (range 18-68). Fourteen patients had POTS, while the other 13 had either mild or no autonomic abnormalities. Patients with POTS were more likely to have delayed small bowel transit (42.9% vs 7.69%, P = 0.037), but no differences were seen in gastric or colonic transit delays (Table 1). Additionally, POTS patients were more likely to exhibit a hypocontractile pattern throughout the gastrointestinal tract compared to non-POTS patients. Specifically, maximal gastric pressure, and small bowel peak amplitude and motility index were significantly lower in POTS patients. There was a trend towards lower colonic maximum pressure, contraction/min and peak amplitude in POTS patients that did not reach significance (Table 1). CONCLUSION: Our data shows that gastrointestinal motility abnormalities, as observed in WMC, are more common in patients with POTS. Patients with POTS were more likely to have delayed small bowel transit, as well as hypocontractile gastrointestinal patterns, particularly in the small bowel, compared to non-POTS patients. WMC offers a unique opportunity to evaluate patients with autonomic dysfunction and POTS. Further prospective evaluation and higher sample sizes are needed.

Mechanisms of tilt-induced vasovagal syncope in healthy volunteers and postural tachycardia syndrome patients without past history of syncope.

Upright tilt table testing has been used to test for vasovagal syncope (VVS) but can result in “false positives” in which tilt‐induced fainting (tilt+) occurs in the absence of real‐world fainting. Tilt+ occurs in healthy volunteers and in patients with postural tachycardia syndrome (POTS) and show enhanced susceptibility to orthostatic hypotension. We hypothesized that the mechanisms for hypotensive susceptibility differs between tilt+ healthy volunteers (Control‐Faint (N = 12)), tilt+ POTS patients (POTS‐Faint (N = 12)) and a non‐fainter control group of (Control‐noFaint) (N = 10). Subjects were studied supine and during 70° upright tilt while blood pressure (BP), cardiac output (CO), and systemic vascular resistance (SVR), were measured continuously. Impedance plethysmography estimated regional blood volumes, flows, and vascular resistance. Heart rate was increased while central blood volume was decreased in both Faint groups. CO increased in Control‐Faint because of reduced splanchnic vascular resistance; splanchnic pooling was similar to Control‐noFaint. Splanchnic blood flow in POTS‐Faint decreased and resistance increased similar to Control‐noFaint but splanchnic blood volume was markedly increased. Decreased SVR and splanchnic arterial vasoconstriction is the mechanism for faint in Control‐Faint. Decreased CO caused by enhanced splanchnic pooling is the mechanism for faint in POTS‐Faint. We propose that intrahepatic resistance is increased in POTS‐Faint resulting in pooling and that both intrahepatic resistance and splanchnic arterial vasoconstriction are reduced in Control‐Faint resulting in increased splanchnic blood flow and reduced splanchnic resistance.

Long-Term Outcomes of Children and Adolescents With Postural Tachycardia Syndrome After Conventional Treatment.

Objectives: To explore the long-term outcomes of children and adolescents with postural tachycardia syndrome receiving conventional interventions.Materials and Methods: A total of 121 patients were recruited, but 6 (5.0%) of them were lost at follow-up. The detailed clinical data were collected, and the reoccurrence and frequency of orthostatic intolerance symptoms were evaluated with a mean followed-up period of 18.7 months (range, 14–74 months). The Kaplan-Meier curve was used to show the cumulative symptom-free rate of patients over time. Factors influencing the long-term outcomes were examined using the Cox's proportional hazards models.Results: The cumulative symptom-free rate was gradually increased over time. It was 48.4% at the 1-year follow-up and increased to 85.6% at the 6-year follow-up. The duration of symptoms before treatment and the maximum upright heart rate in standing-up test were identified as independent indicators for the long-term outcomes. Each 1-month prolongation in the duration of symptoms before treatment was associated with a 1.2% decrease in the cumulative symptom-free rate. However, each 1-bpm increase in the maximum upright heart rate in standing-up test was associated with a 2.1% increase in the cumulative symptom-free rate.Conclusions: The long-term outcomes of postural tachycardia syndrome patients who received conventional interventions are benign and the cumulative symptom-free rate was gradually increased over time. The prolonged duration of symptoms before treatment and the reduced maximum upright heart rate in standing-up test are the independent risk indicators.

A functional cell-based bioassay for assessing adrenergic autoantibody activity in postural tachycardia syndrome

BackgroundActivating autoantibodies (AAb) to adrenergic receptors (AR) have previously been reported in patients with postural tachycardia syndrome (POTS). These AAb may contribute to a final common pathway for overlapping disease processes, reflecting a possible autoimmune contribution to POTS pathophysiology. In prior studies, measurement of AAb activity was inferred from costly, low-throughput, and laborious physiological assays. In the present study, we developed and validated an alternative cell-based bioassay for measuring AAb activity in serum by means of pre-treatment with monoamine oxidase (MAO). MethodsA total of 37 POTS patients and 61 sex-matched healthy control participants were included. Serum was pre-treated with MAO to remove endogenous catecholamines that could falsely inflate AR activation by AAb. A receptor-transfected cell-based bioassay was used to detect presence of α1AR-AAb and β1AR-AAb in serum. ResultsMAO effectively degraded catecholamines as demonstrated by suppression of norepinephrine-induced α1AR activation in POTS (6.4 ​± ​0.7 vs. 5.5 ​± ​0.9; P ​= ​0.044) and in controls (4.1 ​± ​0.5 vs. 3.9 ​± ​0.6; P ​= ​0.001). Mean activity values were greater in the POTS vs. Controls for α1AR-AAb (6.2 ​± ​1.2 vs. 5.3 ​± ​1.0; P ​< ​0.001) and β1AR-AAb (5.7 ​± ​1.8 vs. 4.1 ​± ​0.9; P ​< ​0.001). Compared to controls, more POTS patients were positive for α1AR-AAb activity (22% vs 4%; P ​= ​0.007) and β1AR-AAb activity (52% vs. 2%; P ​< ​0.001). ConclusionsThe co-presence of norepinephrine in serum samples can artifactually elevate α1AR and β1AR activity, which can be avoided by serum pre-treatment with MAO. Using this novel bioassay, we show that POTS patients have increased α1AR-AAb and β1AR-AAb activity compared to healthy controls in the largest POTS cohort reported to-date.

Hemodynamic changes in standing-up test of children and adolescents with postural tachycardia syndrome

To explore the hemodynamic changes in standing-up test of children and adolescents with postural tachycardia syndrome (POTS) and to compare hemodynamic parameters of POTS patients with decreased cardiac index (CI) and those with not-decreased CI. A retrospective study was conducted to show the trends of CI, total peripheral vascular resistance index (TPVRI), heart rate and blood pressure in standing-up test of 26 POTS patients and 12 healthy controls, and to compare them between the two groups. The POTS patients were divided into two groups based on CI decreasing or not in standing-up test, namely decreased CI group (14 cases) and not-decreased CI group (12 cases). The trends of the above mentioned hemodynamic parameters in standing-up test were observed and compared between decreased CI group and not-decreased CI group. In standing-up test for all the POTS patients, CI (F=6.936, P=0.001) and systolic blood pressure (F=6.049, P<0.001) both decreased significantly, and heart rate increased obviously (F=113.926, P<0.001). However, TPVRI (F=2.031, P=0.138) and diastolic blood pressure (F=2.018, P=0.113) had no significant changes. For healthy controls, CI (F=3.646, P=0.016), heart rate (F=43.970, P<0.001), systolic blood pressure (F=4.043, P=0.020) and diastolic blood pressure (F=8.627, P<0.001) all increased significantly in standing-up test. TPVRI (F=1.688, P=0.190) did not change obviously. The changing trends of CI (F=6.221, P=0.001), heart rate (F=6.203, P<0.001) and systolic blood pressure (F=7.946, P<0.001) over time were significantly different between the patients and healthy controls, however, no difference was found in TPVRI and diastolic blood pressure (P > 0.05). Among the POTS patients, CI was significantly different between decreased CI group and not-decreased CI group (F=14.723, P<0.001). Systolic blood pressure of the former decreased obviously (F=8.010, P<0.001), but it did not change obviously in the latter (F=0.612, P=0.639). Furthermore, none of the changes of TPVRI, heart rate and diastolic blood pressure in standing-up test were significantly different between the two groups (P > 0.05). Age was an independent factor for decreased CI patients (P=0.013, OR=2.233; 95% CI, 1.183 to 4.216). POTS patients experience vital hemodynamic changes in standing-up test, part of them suffering from decreased CI, but others from not-decreased CI. Age is an independent factor for patients suffering from decreased CI.

Vagal and Sympathetic Function in Neuropathic Postural Tachycardia Syndrome.

The diagnosis of neuropathic postural tachycardia syndrome (POTS) requires research techniques not available clinically. We hypothesized that these patients will have impaired vagal and sympathetic cardiovascular control that can be characterized with clinical autonomic tests. We included 12 POTS patients with possible neuropathic subtype because of normal plasma norepinephrine and no increase in upright blood pressure. We compared them to 10 healthy subjects. We assessed hemodynamics, heart rate and blood pressure variability, baroreflex sensitivity, raw and integrated muscle sympathetic nerve activity, and blood volume. To understand the vagal/sympathetic control, we dissected the phase 2 of Valsalva maneuver (VM) into early (VM2e) and late (VM2l). POTS' upright heart rate increased 43±3 bpm. Patients had normal plasma volume but reduced red blood cell volume (1.29 L versus predicted normal values 1.58 L; P=0.02). Vagal indices of heart rate variability, HFRRI (430±130 versus 1680±900; P=0.04), PNN50, and root mean squared of successive differences were lower in POTS. Patients showed a decrease in vagal baroreflex sensitivity (VM2e; P=0.04). In POTS, integrated muscle sympathetic nerve activity was lower at rest (12±1.5 versus 20±2 burst/min; P=0.004) and raw muscle sympathetic nerve activity spike analysis showed blunted responses during VM2e, despite a greater drop in systolic blood pressure (34±5 in POTS and 14±6 mm Hg in controls; P=0.01). This cohort of POTS patients enriched for possible neuropathic subtype had lower resting muscle sympathetic nerve activity, impaired vagal cardiac control, and exaggerated drop in blood pressure in response to VM and a delay in the sympathetic cardiovascular responsiveness during hypotensive challenge.

The face of postural tachycardia syndrome - insights from a large cross-sectional online community-based survey.

BackgroundPatients with postural tachycardia syndrome (POTS) experience chronic symptoms of orthostatic intolerance. There are minimal data detailing the demographics, clinical features and clinical course of this condition. This online, community‐based survey highlights patients’ experience with POTS. It consists of the largest sample of POTS patients reported to date.ObjectivesTo describe the demographics, past medical history, medications, treatments and diagnostic journey for patients living with POTS.MethodsPostural tachycardia syndrome patients completed an online, community‐based, cross‐sectional survey. Participants were excluded if they had not received a diagnosis of POTS from a physician. The questions focused on the patient experience and journey, rather than physiological responses.ResultsThe final analysis included 4835 participants. POTS predominantly affects white (93%) females (94%) of childbearing age, with approximately half developing symptoms in adolescence (mode 14 years). POTS is a chronic multisystem disorder involving a broad array of symptoms, with many patients diagnosed with comorbidities in addition to POTS. POTS patients often experience lengthy delays [median (interquartile range) 24 (6–72) months] and misdiagnosis, but the diagnostic delay is improving. POTS patients can present with a myriad of symptoms most commonly including lightheadedness (99%), tachycardia (97%), presyncope (94%), headache (94%) and difficulty concentrating (94%).ConclusionsThese data provide important insights into the background, clinical features and diagnostic journey of patients suffering from POTS. These data should serve as an essential step for moving forward with future studies aimed at early and accurate diagnoses of these patients leading to appropriate treatments for their symptoms.

Orthostatic Cognitive Dysfunction in Postural Tachycardia Syndrome After Rapid Water Drinking.

Background: Postural tachycardia syndrome (POTS) is a form of autonomic dysregulation and is characterized by an excessive heart rate (HR) increment upon the upright body position while blood pressure is maintained. Patients experience typical symptoms of orthostatic intolerance such as dizziness, nausea and cognitive impairments. The present study assessed position-dependent attentional and cognitive functioning in POTS patients compared to healthy subjects and tested the response of cognitive performance to acute water intake.Methods: Data was obtained from eight patients with neuropathic POTS and eight healthy subjects of similar age and gender. All participants completed questionnaires that assessed health-related quality of life and depression and underwent four rounds of neuropsychological testing overall, each before and after the intake of 500 ml still mineral water and both in the supine and in the upright posture.Results: Postural tachycardia syndrome patients showed deficits in working memory (WM) exclusively in the upright position compared to healthy subjects, but no position-dependent impairments in alertness or divided attention. Rapid water ingestion had a beneficial effect on WM in the upright posture, lead to a decrease in HR increment and to an improvement of subjective symptom experience.Conclusion: The results provide support for the occurrence of purely orthostatic cognitive deficits in POTS, especially when increased executive control and cognitive resources are required and document a favorable effect of water intake on cognitive performance. These findings have important implications for the management of cognitive symptoms in POTS as high water intake is an easy and accessible strategy.

Plasma Homocysteine Level in Children With Postural Tachycardia Syndrome.

The study was designed to evaluate the changes of plasma homocysteine (Hcy) level in children with postural tachycardia syndrome (POTS) and explore its significance. A total of 65 subjects were recruited in our study, of whom 35 children were in the POTS group and 30 healthy children were in the control group. Plasma Hcy levels were determined in all subjects. The relationship between the plasma Hcy level and the symptom score was analyzed in the 35 POTS patients. The relationship between the plasma Hcy level and the change in heart rate from the supine to upright position (ΔHR) and between the plasma Hcy level and the rate of increase in heart rate from the supine to upright position (ΔHR/sHR × 100%) were analyzed in all subjects. The plasma Hcy levels were significantly higher in the children with POTS than those in the control group (9.78 [7.68, 15.31] μmol/L vs. 7.79 [7.46, 9.63] μmol/L, P < 0.05). The plasma Hcy levels were positively correlated with symptom scores in the POTS patients (n = 35, r = 0.522, P < 0.01). The plasma Hcy levels were also positively correlated with ΔHR (n = 65, r = 0.332, P < 0.01) and ΔHR/sHR × 100% (n = 65, r = 0.341, P < 0.01) in all the subjects. In conclusion, the plasma Hcy levels were elevated in the children with POTS positively correlated with the severity of POTS, suggesting that Hcy might be involved in the pathogenesis of POTS.

Abstract P387: Sub-Perception Transdermal Vagal Stimulation in Postural Tachycardia Syndrome

Postural Tachycardia Syndrome (POTS) is a clinical syndrome characterized by an excessive increase in heart rate (&gt;= 30 bpm) on standing in the absence of orthostatic hypotension, and frequent orthostatic symptoms for more than 6 months. While most researchers focus on the hyperadrenergic features of POTS, these patients also have significant cardio-vagal (parasympathetic) impairment. We tested the hypothesis that transdermal electrical stimulation of the auricular branch of the vagus nerve will enhance cardio-vagal modulation, reduce heart rate, upright symptoms, and improve orthostatic tolerance. We studied 14 patients with POTS (31.5+/-11.7 years, BMI 22.6+/-3.9 kg/m 2 ). Sham or sub-perception threshold transdermal electrical vagal stimulation was applied in random order to the auricular branch in the right ear in supine and during graded tilt maneuver. Patients with low vagal modulation (low high frequency HF &lt; 200 ms 2 ) responded to vagal stimulation (Kruskal Wallis p=0.01, n=7, Fig left) with significant increase in HF power (eg @50Hz: +51+/-10 ms 2 , p=0.0032). Vagal stimulation during upright tilt tended to reduce orthostatic tachycardia and overall orthostatic symptom score. It improved significantly tilt time (+5.3+/-2.6 min, p=0.0156, Fig right). Patients with higher baseline vagal modulation (HF &gt;= 200 ms 2 ) did not respond to vagal stimulation (interaction p=0.41). This proof of concept study indicates that auricular transdermal vagal stimulation improves supine cardio-vagal function in POTS patients with low vagal modulation. Further research will determine if this approach can be used therapeutically, alone or in combination with other therapies.

Cognitive and psychological issues in postural tachycardia syndrome

Postural tachycardia syndrome (POTS) is one of the most common forms of chronic orthostatic intolerance. In addition to orthostatic symptoms, many POTS patients report incapacitating cognitive dysfunction or "brain fog" even while lying down or seated. Consistent with these subjective reports, there is accruing objective evidence of specific cognitive difficulties in POTS, with studies showing mild to moderate cognitive impairment using standardized neuropsychological assessment batteries. The precise profile of cognitive dysfunction in POTS patients has been shown to vary among these studies potentially due to the neuropsychological tests used, postural position, comorbidities and length of illness, inclusion of adolescent versus adult patients, and sites of recruitment. The extent of the impact that this cognitive challenge has in patients justifies ongoing investigation and research into lifestyle and pharmacological treatments. Psychologically, patients face challenges congruent with many chronic illnesses, perhaps especially early in adjusting to the condition. POTS patients often exhibit mild to moderate depression symptoms as well as symptoms of anxiety disorders. Since even low levels of anxiety can exacerbate symptoms, and a high number of patients experience sub-clinical low mood and sleep disturbances, there is a likely role for psychotherapy in helping control adjustment-related issues, and possibly aberrant physiology, in POTS.

Gastrointestinal symptoms in postural tachycardia syndrome: a systematic review.

Gastrointestinal symptoms are among the most common complaints in patients with postural tachycardia syndrome (POTS). In some cases, they dominate the clinical presentation and cause substantial disabilities, including significant weight loss and malnutrition, that require the use of invasive treatment to support caloric intake. Multiple cross-sectional studies have reported a high prevalence of gastrointestinal symptoms in POTS patients with connective tissue diseases, such as Ehlers-Danlos, hypermobile type, and in patients with evidence of autonomic neuropathy. Previous studies that evaluated gastric motility in these patients reported a wide range of abnormalities, particularly delayed gastric emptying. The pathophysiology of gastrointestinal symptoms in POTS is likely multifactorial and probably depends on the co-morbid conditions. In patients with POTS and Ehlers-Danlos syndromes, structural and functional abnormalities in the gastrointestinal connective tissue may play a significant role, whereas in neuropathic POTS, the gastrointestinal tract motility and gut hormonal secretion may be directly impaired due to localized autonomic denervation. In patients with normal gastrointestinal motility but persistent gastrointestinal symptoms, gastrointestinal functional disorders should be considered. We performed a systematic review of the literature related to POTS and gastrointestinal symptoms have proposed possible mechanisms and discussed diagnosis and treatment approaches for delayed gastric emptying, the most common gastrointestinal abnormality reported in patients with POTS.

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

NCT02171988.

Overview of the management of postural tachycardia syndrome in pregnant patients

Postural tachycardia syndrome (POTS) is a chronic condition characterized by symptoms of orthostatic intolerance. Pregnancy can cause different physiological changes in cardiovascular parameters, that could have greater impact on POTS patients. In this review, we discuss the management of POTS in the pregnant and obstetric settings.

Emotional orienting during interoceptive threat in orthostatic intolerance: Dysautonomic contributions to psychological symptomatology in the postural tachycardia syndrome and vasovagal syncope.

Cognitive and emotional processes are influenced by interoception (homeostatic somatic feedback), particularly when physiological arousal is unexpected and discrepancies between predicted and experienced interoceptive signals may engender anxiety. Due to the vulnerability for comorbid psychological symptoms in forms of orthostatic intolerance (OI), this study investigated psychophysiological contributions to emotional symptomatology in 20 healthy control participants (13 females, mean age 36 ± 8 years), 20 postural tachycardia syndrome (PoTS) patients (18 females, mean age 38 ± 13 years) and 20 vasovagal syncope (VVS) patients (15 females, mean age 39 ± 12 years). We investigated indices of emotional orienting responses (OR) to randomly presented neutral, pleasant and unpleasant images in the supine position and during the induced interoceptive threat of symptom provocation of head-up tilt (HUT). PoTS and VVS patients produced greater indices of emotional responsivity to unpleasant images and, to a lesser degree, pleasant images, during interoceptive threat. Our findings are consistent with biased deployment of response-focused emotion regulation (ER) while patients are symptomatic, providing a mechanistic underpinning of how pathological autonomic overexcitation predisposes to anxiogenic traits in PoTS and VVS patients. This hypothesis may improve our understanding of why orthostasis exacerbates cognitive symptoms despite apparently normal cerebral autoregulation, and offer novel therapeutic targets for behavioural interventions aimed at reducing comorbid cognitive-affective symptoms in PoTS and VVS.

Postural tachycardia in hypermobile Ehlers-Danlos syndrome: A distinct subtype?

It is not clear if patients with postural tachycardia syndrome (POTS) and Ehlers-Danlos syndrome (hEDS) differ from patients with POTS due to other etiologies. We compared the results of autonomic testing and healthcare utilization in POTS patients with and without hEDS. Patients with POTS+hEDS (n=20) and POTS controls without hypermobility (n=20) were included in the study. All patients underwent autonomic testing, and the electronic medical records were reviewed to determine the number and types of medications patients were taking, as well as the number of outpatient, emergency department, and inpatient visits over the prior year. Patients with hEDS had twice as many outpatient visits (21 v. 10, p=0.012), were taking more prescription medications (8 vs. 5.5, p=0.030), and were more likely to see a pain physician (70% vs 25%, p=0.005). Autonomic testing demonstrated a slight reduction in heart rate variability and slightly lower blood pressures on tilt table testing in hEDS patients, however for most patients these variables remained within the range of normal. Orthostatic tachycardia on tilt table testing was greater in POTS controls (46bpm vs 39bpm, p=0.018). Abnormal QSweat responses were common in both groups (38% of POTS+hEDS and 36% of POTS controls). While autonomic testing results were not significantly different between groups, patients with POTS+hEDS took more medications and had greater markers of healthcare utilization, with chronic pain likely playing a prominent role.