To define the neuropathology, clinical phenotype, autonomic physiology and differentiating features in individuals with neuropathic and non-neuropathic postural tachycardia syndrome (POTS). Twenty-four subjects with POTS and 10 healthy control subjects had skin biopsy analysis of intra-epidermal nerve fiber density (IENFD), quantitative sensory testing (QST) and autonomic testing. Subjects completed quality of life, fatigue and disability questionnaires. Subjects were divided into neuropathic and non-neuropathic POTS, defined by abnormal IENFD and abnormal small fiber and sudomotor function. Nine of 24 subjects had neuropathic POTS and had significantly lower resting and tilted heart rates; reduced parasympathetic function; and lower phase 4 valsalva maneuver overshoot compared with those with non-neuropathic POTS (P<0.05). Neuropathic POTS subjects also had less anxiety and depression and greater overall self-perceived health-related quality of life scores than non-neuropathic POTS subjects. A sub-group of POTS patients (cholinergic POTS) had abnormal proximal sudomotor function and symptoms that suggest gastrointestinal and genitourinary parasympathetic nervous system dysfunction. POTS subtypes may be distinguished using small fiber and autonomic structural and functional criteria. Patients with non-neuropathic POTS have greater anxiety, greater depression and lower health-related quality of life scores compared to those with neuropathic POTS. These findings suggest different pathophysiological processes underlie the postural tachycardia in neuropathic and non-neuropathic POTS patients. The findings have implications for the therapeutic interventions to treat this disorder.

The symptom of fatigue is frequently described by patients attending the syncope unit with a wide range of conditions including vasovagal syncope and postural orthostatic tachycardia syndrome. It is possible that the presence of autonomic dysfunction provides the common pathogenetic mechanism linking neurally mediated hypotension and fatigue. Managing this debilitating symptom can often be challenging but, with a structured approach, immensely rewarding, and as a result improve how patients cope with their disease.

Postural tachycardia syndrome (POTS) is one of the most frequent forms of chronic orthostatic intolerance in children and adolescents. The aim of the present study was to examine the influence of a genetic background on POTS. A total of 96 children and adolescents with orthostatic dysregulation were studied. The polymorphism of the G protein β3 subunit (GNB3) C825T and G protein α subunit (GNAS1) T131C of genes encoding components of the autonomic nervous system were determined and compared with circulatory responses to active standing. In the GNB3 gene C825T polymorphism, the CT and TT genotype had a significant lower supine heart rate and a larger increase of heart rate by standing than the CC, associated with evaluated power of the high-frequency component of heart rate variability. According to the criteria of the Japanese clinical guidelines, 48 children were diagnosed as POTS and 30 were as normal responder with somatoform disorder (SD). In GNB3 C825T polymorphism, the TT genotype was more frequently found in the POTS group (45.8%) than in the SD group (20.0%; P = 0.036) [corrected]. In the GNAS1 T393C, the genotype frequencies for the T393C polymorphisms of GNA1 did not differ significantly between the groups. The gene polymorphisms GNB3 C825T might be a risk factor for POTS through the enhanced vagal withdrawal of the heart in children and adolescents.

Autoantibodies are implicated in the pathogenesis of cardiovascular diseases and cardiac arrhythmias. In this pilot study, we tested the hypothesis that autoantibodies are present in patients with postural orthostatic tachycardia syndrome (POTS). Seven control subjects (6 F:1 M, average age 36.1 years) and ten patients with the diagnosis of POTS (7 F: 3 M, average age 35.1 years) provided informed consent and 30 mL of venous blood. Human heart membrane proteins were resolved by 2DE and immunoblotted against purified IgGs from controls and patients. Eighteen protein spots immunoreactive specifically against patient IgGs were detected and they were excised from gels, trypsin-digested, and analyzed by nanoLC-electrospray MS/MS. Forty unique proteins were identified and these include proteins that are associated with cardiac hypertrophy (mimecan, myozenin), cardiac remodeling (periostin), cardiomyopathy (desmin, desmoplakin), cell survival (laminin), structural integrity (filamin), chaperone proteins (crystalline, HSP70), mitochondrial enzymes, and channel proteins. Ingenuity Pathway Analysis showed multiple pathways were involved including those that regulate energy metabolism, redox, fibrosis, cardiac hypertrophy, and degeneration. Autoantibodies are present in patients with POTS. These autoantibodies cross-react with a wide range of cardiac proteins and may induce alterations in cardiac function. Autoimmune pathogenetic mechanisms should be further explored in these patients.

Approximately 80-90% of the norepinephrine released in the brain or in peripheral tissues is taken up again through the neuronal norepinephrine transporter (NET). Pharmacological studies with NET inhibitors showed that NET has opposing effects on cardiovascular sympathetic regulation in the brain and in the periphery. Furthermore, NET is involved in the distribution of sympathetic activity between vasculature, heart, and kidney. Genetic NET dysfunction is a rare cause of the postural tachycardia syndrome. The condition is characterized by excessive adrenergic stimulation of the heart, particularly with standing. Conversely, NET inhibition may be beneficial in hypoadrenergic states, such as central autonomic failure or neurally mediated syncope, which results from acute sympathetic withdrawal. Biochemical studies suggested reduced NET function in some patients with essential hypertension. Furthermore, cardiac NET function appears to be reduced in common heart diseases, such as congestive heart failure, ischemic heart disease, and stress-induced cardiomyopathy. Whether NET dysfunction is a consequence or cause of progressive heart disease in human subjects requires further study. However, studies with the nonselective NET inhibitor sibutramine suggest that reduced NET function could have an adverse effect on the cardiovascular system. Given the widespread use of medications inhibiting NET, the issue deserves more attention.

Postural tachycardia syndrome (POTS) is defined by a heart rate increment of 30 beats/min or more within 10 minutes of standing or head-up tilt in the absence of orthostatic hypotension; the standing heart rate is often 120 beats/min or higher. POTS manifests with symptoms of cerebral hypoperfusion and excessive sympathoexcitation. The pathophysiology of POTS is heterogeneous and includes impaired sympathetically mediated vasoconstriction, excessive sympathetic drive, volume dysregulation, and deconditioning. POTS is frequently included in the differential diagnosis of chronic unexplained symptoms, such as inappropriate sinus tachycardia, chronic fatigue, chronic dizziness, or unexplained spells in otherwise healthy young individuals. Many patients with POTS also report symptoms not attributable to orthostatic intolerance, including those of functional gastrointestinal or bladder disorders, chronic headache, fibromyalgia, and sleep disturbances. In many of these cases, cognitive and behavioral factors, somatic hypervigilance associated with anxiety, depression, and behavioral amplification contribute to symptom chronicity. The aims of evaluation in patients with POTS are to exclude cardiac causes of inappropriate tachycardia; elucidate, if possible, the most likely pathophysiologic basis of postural intolerance; assess for the presence of treatable autonomic neuropathies; exclude endocrine causes of a hyperadrenergic state; evaluate for cardiovascular deconditioning; and determine the contribution of emotional and behavioral factors to the patient's symptoms. Management of POTS includes avoidance of precipitating factors, volume expansion, physical countermaneuvers, exercise training, pharmacotherapy (fludrocortisone, midodrine, β-blockers, and/or pyridostigmine), and behavioral-cognitive therapy. A literature search of PubMed for articles published from January 1, 1990, to June 15, 2012, was performed using the following terms (or combination of terms): POTS; postural tachycardia syndrome, orthostatic; orthostatic; syncope; sympathetic; baroreceptors; vestibulosympathetic; hypovolemia; visceral pain; chronic fatigue; deconditioning; headache; Chiari malformation; Ehlers-Danlos; emotion; amygdala; insula; anterior cingulate; periaqueductal gray; fludrocortisone; midodrine; propranolol; β-adrenergic; and pyridostigmine. Studies were limited to those published in English. Other articles were identified from bibliographies of the retrieved articles.

Sympathetic circulatory control is key to the rapid cardiovascular adjustments that occur within seconds of standing upright (orthostasis) and which are required for bipedal stance. Indeed, patients with ineffective sympathetic adrenergic vasoconstriction rapidly develop orthostatic hypotension, prohibiting effective upright activities. One speaks of orthostatic intolerance (OI) when signs, such as hypotension, and symptoms, such as lightheadedness, occur when upright and are relieved by recumbence. The experience of transient mild OI is part of daily life. However, many people experience episodic acute OI as postural faint or chronic OI in the form of orthostatic tachycardia and orthostatic hypotension that significantly reduce the quality of life. Potential mechanisms for OI are discussed including forms of sympathetic hypofunction, forms of sympathetic hyperfunction, and OI that results from regional blood volume redistribution attributable to regional adrenergic hypofunction.

Orthostasis means standing upright. One speaks of orthostatic intolerance (OI) when signs, such as hypotension, and symptoms, such as lightheadedness, occur when upright and are relieved by recumbence. The experience of transient mild OI is part of daily life. 'Initial orthostatic hypotension' on rapid standing is a normal form of OI. However, other people experience OI that seriously interferes with quality of life. These include episodic acute OI, in the form of postural vasovagal syncope, and chronic OI, in the form of postural tachycardia syndrome. Less common is neurogenic orthostatic hypotension, which is an aspect of autonomic failure. Normal orthostatic physiology and potential mechanisms for OI are discussed, including forms of sympathetic hypofunction, forms of sympathetic hyperfunction and OI that results from regional blood volume redistribution. General and specific treatment options are proposed.

To study the frequency and degree of deconditioning, clinical features, and relationship between deconditioning and autonomic parameters in patients with orthostatic intolerance. We retrospectively studied all patients seen for orthostatic intolerance at Mayo Clinic between January 2006 and June 2011, who underwent both standardized autonomic and exercise testing. A total of 184 patients (84 with postural orthostatic tachycardia syndrome [POTS] and 100 without orthostatic tachycardia) fulfilled the inclusion criteria. Of these, 89% were women, and median age was 27.5 years (interquartile range [IQR] 22-37 years). Symptom duration was 4 years (IQR 2-7.8). Of the patients, 90% had deconditioning (reduced maximum oxygen uptake [VO(2max)%] <85%) during exercise. This finding was unrelated to age, gender, or duration of illness. The prevalence of deconditioning was similar between those with POTS (95%) and those with orthostatic intolerance (91%). VO(2max)% had a weak correlation with a few autonomic and laboratory parameters but adequate predictors of VO(2max)% could not be identified. Reduced VO(2max)% consistent with deconditioning is present in almost all patients with orthostatic intolerance and may play a central role in pathophysiology. This finding provides a strong rationale for retraining in the treatment of orthostatic intolerance. None of the autonomic indices are reliable predictors of deconditioning.

Syncope is defined as transient loss of consciousness and muscle tone, usually of short duration. Noncardiac causes of syncope are classified as orthostatic intolerance syndromes (OIS). QT and QTc (corrected QT) dispersions are the measurements of myocardial instability and show predisposition to arrhythmias. In this study; clinical findings, QT and QTc dispersions of the patients who were diagnosed as OIS were evaluated retrospectively. Also, the aim of the study is to clarify the association of clinical characteristics of unexplained syncope with the outcome of the QT and QTc dispersions in children. We designed a retrospective study including 152 children and adolescents who had repeated unexplained syncope or presyncope between June 2002 and August 2010. Head-up Tilt table test (HUTT) were performed for all patients. Control group consisted of 67 healthy children. The QT and QTc dispersions were measured from the 12 ECG leads. Eighty-four (55.2%) patients had positive and 68 (44.8%) had negative response to HUTT. QT and QTc dispersions were significantly higher in HUTT-positive group than in negative (p < 0.01, p < 0.001 respectively). Also, QTc dispersion was significantly higher in both vasovagal syncope and postural orthostatic tachycardia syndrome groups than in HUTT-negative group (p < 0.001, p < 0.05 respectively). Specifity and sensitivity of QTc dispersion for predicting positive HUTT are 76.5% and 59.5% respectively. The positive predictive value of the test calculated as 75.8%. These results revealed that we can use QTc dispersion measurement as a noninvasive electrocardiographic test to evaluate OIS for predicting positive result before performing HUTT.

Postural tachycardia syndrome (POTS), a disorder of the autonomic nervous system, predominantly occurs in women of child-bearing age. We set out to determine the clinical course and maternal and fetal outcomes in pregnant women with pre-existing POTS. Participants were asked to complete a detailed questionnaire assessing the clinical course of POTS before, during and after pregnancy, as well as complications of pregnancy, labor and delivery and fetal outcomes. Among 10 women with pre-existing POTS (pregnancy age 28 ± 7 years, range 16-39), with a total of 17 live births, two were complicated by pre-eclampsia, 14 were normal vaginal deliveries and three were C-sections. The rate of severe vomiting or hyperemesis gravidarum in the first trimester was 59%. There were no stillbirths or congenital abnormalities. The average birth weight was 3076 ± 733 grams, with two infants born premature. During pregnancy, POTS symptoms were either improved or stable in six of 10 women, and four of these six women utilized medications for POTS. Six months after delivery, POTS symptoms were improved in three, stable in two and worsened in five women compared to before pregnancy. POTS may have a variable clinical course in pregnancy, with 60% of women reporting either improved or stable symptoms during pregnancy, and 50% of women reporting either improved or stable symptoms 6 months after delivery. There may be a higher rate of severe vomiting in the first trimester in women with POTS than in general population.

Postural tachycardia syndrome (POTS) induces disabling chronic orthostatic intolerance with an excessive increase in heart rate on standing, and many patients with POTS have low blood volume. Increasing blood volume is a promising approach to this problem. To test the hypothesis that desmopressin (DDAVP) will attenuate the tachycardia and improve symptom burden in patients with POTS. In this protocol, patients with POTS (n = 30) underwent acute drug trials with DDAVP 0.2 mg orally and placebo, on separate mornings, in a randomized crossover design. Blood pressure, heart rate, and symptoms were assessed while seated and after standing for up to 10 minutes prior to and hourly for 4 hours following study drug. The standing heart rate was significantly lower following DDAVP than placebo (101.9 ± 14.5 beats/min vs 109.2 ± 17.4 beats/min; P <.001). Standing blood pressure was not affected (P = .28). The symptom burden improved with DDAVP (from a score of 18 ± 18 arbitrary units [AU] to 13 ± 15 AU at 2 hours) compared with placebo (from 18 ± 17 AU to 19 ± 16 AU; P = .010). Oral DDAVP significantly attenuated tachycardia and improved symptoms in POTS. The safety profile of this approach would need to be examined before it can be recommended for routine treatment of these patients.

To assess differences in gynecologic history and lightheadedness during menstrual cycle phases among patients with POTS and healthy control women. In a prospective, questionnaire-based study carried out at Paden Autonomic Dysfunction Center, Vanderbilt University, between April 2005 and January 2009, a custom-designed questionnaire was administered to patients with POTS (n=65) and healthy individuals (n=95). The results were analyzed via Fisher exact test and Mann-Whitney U test. Patients with POTS reported increased lightheadedness through all phases of the menstrual cycle phases as compared with healthy controls. Both groups experienced the greatest lightheadedness during menses, and a decrease in lightheadedness during the follicular phase. Patients with POTS reported a higher incidence of gynecologic diseases as compared with healthy controls. The severity of lightheadedness was found to vary during the menstrual cycle, which may relate to changes in estrogen levels. Patients with POTS also reported an increase in estrogen-related gynecologic disease.

We report a case of postural tachycardia syndrome occurring after the surgical correction of an aortic coarctation, and coexisting with upper airway resistance syndrome. A 29-year-old Caucasian man complained of extreme fatigue, daytime sleepiness, shortness of breath on exertion, light-headedness and general weakness on standing. These symptoms began shortly after the surgical correction of an aortic coarctation and became progressively more debilitating, impairing any daily activity. An extensive work-up revealed postural tachycardia syndrome and a coexisting sleep-related breathing disorder, characterized as upper airway resistance syndrome. This is the first reported case describing the occurrence of postural tachycardia syndrome after the surgical correction of an aortic coarctation. This case also provides evidence for the suggestion that this syndrome may coexist with upper airway resistance syndrome, although the exact nature of their relationship must still be better established.

A 37-year-old woman presented with a history of reactive hypoglycaemia, non-classic adrenal hyperplasia (NCAH), osteopenia and fibromyalgia. After several months of palpitations, postural orthostatic tachycardia syndrome (POTS) was diagnosed by tilt table studies. Her heart rate (HR) reached 191 bpm at 60 degrees from horizontal. Investigation suggested increase in epinephrine and norepinephrine levels in response to tilt table. Her 25(OH) vitamin D level measured by immunoextraction radioimmunoassay was 35 pg/ ml (normal 9-54 pg/ml) while her 1,25(OH)(2) vitamin D3 level was 24 pg/ml (normal 30-67 pg/ml). Accordingly, she was started on calcitriol 0.25 mcg orally daily. At her next visit after 5 months, she reported remarkable improvement in her palpitations and had been working full time for the past 4 months. HR both seated and upright was 72 bpm. After 3 months, her 1,25(OH)(2) vitamin D3 level on calcitriol was 40 pg/ml. The authors suggest that 1-α hydroxylation defects should be sought and treated, if present, with calcitriol in patients with POTS.

Postural tachycardia syndrome (POTS) is a form of orthostatic intolerance characterized by a marked increase in heart rate within the first 10 min of head-up tilt (HUT). We present a patient whose enlarged inferior vena cava that appears to be a contributing mechanism to her POTS and presyncopal symptoms.

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). 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. 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. 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.

Recent studies have suggested the presence of cardiac atrophy as a key component of the pathogenesis of the postural orthostatic tachycardia syndrome (POTS), similar to physical deconditioning. It has also been shown that exercise intolerance is associated with a reduced stroke volume (SV) in POTS, and that the high heart rate (HR) observed at rest and during exercise in these patients is due to this low SV. We tested the hypotheses that (a) circulatory control during exercise is normal in POTS; and (b) that physical ‘reconditioning' with exercise training improves exercise performance in patients with POTS. Nineteen (18 women) POTS patients completed a 3 month training programme. Cardiovascular responses during maximal exercise testing were assessed in the upright position before and after training. Resting left ventricular diastolic function was evaluated by Doppler echocardiography. Results were compared with those of 10 well-matched healthy sedentary controls. A lower SV resulted in a higher HR in POTS at any given oxygen uptake (V(O(2))) during exercise while the cardiac output (Q(c))-V(O(2)) relationship was normal. V(O(2peak)) was lower in POTS than controls (26.1 ± 1.0 (SEM) vs. 36.3 ± 0.9 ml kg-1 min-1; P < 0.001) due to a lower peak SV (65 ± 3 vs. 80 ± 5 ml; P = 0.009). After training in POTS, HR became lower at any given due to increased SV without changes in the – relationship. V(O(2peak)) increased by 11% (P < 0.001) due to increased peak SV (P = 0.021) and was proportional to total blood volume. Peak HR was similar, but HR recovery from exercise was faster after training than before training (P = 0.036 for training and 0.009 for interaction). Resting diastolic function was mostly normal in POTS before training, though diastolic suction was impaired (P = 0.023). There were no changes in any Doppler index after training. These results suggest that short-term exercise training improves physical fitness and cardiovascular responses during exercise in patients with POTS.

The postural tachycardia syndrome (POTS) has multiple symptoms, chief among which are tachycardia, weakness, and recurrent blackouts while standing. Previous research has implicated dysfunction of the norepinephrine transporter. A coding mutation in the norepinephrine transporter gene (SLC6A2) sequence has been reported in 1 family kindred only. The goal of the present study was to further characterize the role and regulation of the SLC6A2 gene in POTS. Sympathetic nervous system responses to head-up tilt were examined by combining norepinephrine plasma kinetics measurements and muscle sympathetic nerve activity recordings in patients with POTS compared with that in controls. The SLC6A2 gene sequence was investigated in leukocytes from POTS patients and healthy controls using single nucleotide polymorphisms genotyping, bisulphite sequencing, and chromatin immunoprecipitation assays for histone modifications and binding of the transcriptional regulatory complex, methyl-CpG binding protein 2. The expression of norepinephrine transporter was lower in POTS patients compared with healthy volunteers. In the absence of altered SLC6A2 gene sequence or promoter methylation, this reduced expression was directly correlated with chromatin modifications. We propose that chromatin-modifying events associated with SLC6A2 gene suppression may constitute a mechanism of POTS.

To prospectively evaluate patients who met standard criteria for postural tachycardia syndrome (POTS), at baseline and 1-year follow-up, using standard clinical and laboratory methods to assess autonomic function. Fifty-eight patients met the study criteria (orthostatic symptoms and a heart rate increment of ≥ 30 beats/min on head-up tilt) and completed 12 months of follow-up. All patients were enrolled and completed the study from January 16, 2006, through April 15, 2009. Patients underwent standardized autonomic testing, including head-up tilt, clinical assessment, and validated questionnaires designed to determine the severity of autonomic symptoms. Patients were predominantly young females (n=49, 84%), with 20 patients (34%) reporting an antecedent viral infection before onset of symptoms. More than one-third (37%) no longer fulfilled tilt criteria for POTS on follow-up, although heart rate increment on head-up tilt did not differ significantly at 1 year (33.8 ± 15.1 beats/min) compared with baseline (37.8 ± 14.6 beats/min) for the entire cohort. Orthostatic symptoms improved in most patients. Autonomic dysfunction was mild as defined by a Composite Autonomic Severity Score of 3 or less in 55 patients (95%) at baseline and 48 patients (92%) at 1 year. To our knowledge, this is the first prospective study of the clinical outcomes of patients with POTS. Orthostatic symptoms improved in our patients, with more than one-third of patients no longer fulfilling tilt criteria for POTS, although the overall group change in heart rate increment was modest. Our data are in keeping with a relatively favorable prognosis in most patients with POTS.

This article identifies the pertinent historical issues that lead to the identification of those headaches needing additional testing to exclude a serious underlying cause. Recurrences of giant cell arteritis, even after presumed successful treatment, are common. Postural orthostatic tachycardia syndrome is an often unrecognized cause of headache. Patients with a primary headache disorder are more susceptible to the development of headache when a secondary cause occurs. Their headaches may be phenotypically similar to their primary headache disorder. Therefore, a secondary cause should be considered in patients with preexisting headache disorders who develop a significant increase in the number and severity of those attacks.

This study was designed to explore the predictive value of the midregional fragment of pro-adrenomedullin (MR-proADM) in assessing the therapeutic efficacy of midodrine hydrochloride for children with postural orthostatic tachycardia syndrome (POTS). Midodrine hydrochloride is an important therapeutic option for children with POTS. However, there has not been any method to predict response to the drug. The MR-proADM is produced in equimolar amounts to adrenomedullin (ADM), and directly reflects levels of the rapidly degraded active peptide, ADM. Fifty-seven children with POTS were designated as the POTS group. Twenty healthy children served as the control group. The children in the POTS group received midodrine hydrochloride treatment. The plasma concentration of MR-proADM was measured, using a sandwich immunoluminometric assay. A receiver-operating characteristic curve was used to explore the predictive value of MR-proADM. Plasma levels of MR-proADM were significantly higher in children with POTS (75.0 [62.5 to 96.0] pg/ml) than in the control group (58.5 [50.3 to 69.0] pg/ml). Plasma levels of MR-proADM in responders to midodrine hydrochloride was significantly higher than that of nonresponders (76.0 [66.0 to 91.0] pg/ml vs. 59.0 [54.0 to 65.5] pg/ml, p < 0.01]. A receiver-operating characteristic curve on the predictive value of MR-proADM showed that the area under the curve was 0.879 with a 95% confidence interval of 0.761 to 0.997. Using a cutoff value for MR-proADM of 61.5 pg/ml produced both high sensitivity (100%) and specificity (71.6%) in predicting the efficacy of midodrine hydrochloride therapy for treating POTS. MR-proADM can help guide midodrine hydrochloride therapy in the management of POTS in children.

Postural orthostatic tachycardia syndrome (POTS) affects women of child-bearing age. There are little reported data on the outcomes of pregnancy in women with POTS. The most common mode of delivery reported in the literature is the caesarean section. Here we describe a woman with POTS who delivered vaginally without any complications and present a comprehensive review of the literature on pregnancy in POTS.

Postural tachycardia syndrome (POTS) refers to the presence of orthostatic intolerance symptoms with a heart rate increment ≥ 30 bpm, usually up to ≥ 120 bpm. Pathophysiology and POTS's clinical presentation are heterogeneous and its prognosis is uncertain. We reviewed the major clinical characteristics of POTS patients and assessed their long-term follow-up. Our series results, one with the longest follow-up, illustrate POTS as a clinical entity with variable, but usually benign outcome, in which most patients can reassume their daily activities without great limitations, after proper diagnosis and treatment are made.

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.