Background Patients 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. Objectives To describe the demographics, past medical history, medications, treatments and diagnostic journey for patients living with POTS. Methods Postural 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. Results The 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%). Conclusions These 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.

2This paper provides recommendations on the treatment of orthostatic hypotension (OH) as reviewed by the American Society of Hypertension. It focuses on recent reports on the evaluation and management of OH and provides practical advice for clinicians on how to screen, diagnose, and treat patients using behavioral, nonpharmacologic, and pharmacologic strategies. The authors also provide a stepwise approach on how to apply new findings to successfully control OH and reduce the risk of syncope and falls in these patients. Treatment of OH is also discussed in special situations such as in hypertensive and hospitalized patients. It should be noted, however, that research in this area is mostly limited to studies in small numbers of patients. Unfortunately, the trials of the type needed to develop evidence-based guidelines are not available for this condition. J Clin Hypertens (Greenwich). 2013;15:147-153. ª2013 Wiley Periodicals, Inc.

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A blunted HR increase during hypotension suggests a neurogenic cause. A ΔHR/ΔSBP ratio < 0.5 bpm/mmHg is diagnostic of neurogenic OH. Ann Neurol 2018;83:522-531.

Abstract-Postural tachycardia syndrome (POTS) is a disabling condition that commonly affects otherwise normal young females. Because these patients can present with a flushing disorder, we hypothesized that mast cell activation (MCA) can contribute to its pathogenesis. Here we describe POTS patients with MCA (MCAϩPOTS), diagnosed by episodes of flushing and abnormal increases in urine methylhistamine, and compared them to POTS patients with episodic flushing but normal urine methylhistamine and to normal healthy age-matched female controls. MCAϩPOTS patients were characterized by episodes of flushing, shortness of breath, headache, lightheadedness, excessive diuresis, and gastrointestinal symptoms such as diarrhea, nausea, and vomiting. Triggering events include long-term standing, exercise, premenstrual cycle, meals, and sexual intercourse. In addition, patients were disabled by orthostatic intolerance and a characteristic hyperadrenergic response to posture, with orthostatic tachycardia (from 79Ϯ4 to 114Ϯ6 bpm), increased systolic blood pressure on standing (from 117Ϯ5 to 126Ϯ7 mm Hg versus no change in POTS controls), increased systolic blood pressure at the end of phase II of the Valsalva maneuver (157Ϯ12 versus 117Ϯ9 in normal controls and 119Ϯ7 mm Hg in POTS; Pϭ0.048), and an exaggerated phase IV blood pressure overshoot (50Ϯ10 versus 17Ϯ3 mm Hg in normal controls; PϽ0.05). In conclusion, MCA should be considered in patients with POTS presenting with flushing. These patients often present with a typical hyperadrenergic response, but ␤-blockers should be used with great caution, if at all, and treatment directed against mast cell mediators may be required.

Abstract-Obesity is associated with alterations in the autonomic nervous system that may contribute to the increase in blood pressure and resting energy expenditure present in this condition. To test this hypothesis, we induced autonomic withdrawal with the ganglionic blocker trimethaphan in 10 lean (32Ϯ3 years) and 10 obese (35Ϯ3 years) subjects. Systolic blood pressure fell more in obese compared with lean subjects (Ϫ17Ϯ3 versus Ϫ11Ϯ1 mm Hg; Pϭ0.019) because of a greater decrease in total peripheral resistance (Ϫ310Ϯ41 versus 33Ϯ78 dynes/sec/cm Ϫ5; Pϭ0.002). In contrast, resting energy expenditure decreased less in obese than in lean subjects, (Ϫ26Ϯ21 versus Ϫ86Ϯ15 kcal per day adjusted by fat-free mass; Pϭ0.035). We confirmed that the autonomic contribution to blood pressure was greater in obesity after including additional subjects with a wider range of blood pressures. Systolic blood pressure decreased Ϫ28Ϯ4 mm Hg (95% CI: Ϫ38 to Ϫ18.0; nϭ8) in obese hypertensive subjects compared with lean (Ϫ9Ϯ1 mm Hg; 95% CI: Ϫ11 to Ϫ6; nϭ22) or obese normotensive subjects (Ϫ14Ϯ2 mm Hg; 95% CI: Ϫ18 to Ϫ10; nϭ20). After removal of autonomic influences, systolic blood pressure remained higher in obese hypertensive subjects (109Ϯ3 versus 98Ϯ2 mm Hg in lean and 103Ϯ2 mm Hg in obese normotensive subjects; Pϭ0.004) suggesting a role for additional factors in obesity-associated hypertension. In conclusion, sympathetic activation induced by obesity is an important determinant to the blood pressure elevation associated with this condition but is not effective in increasing resting energy expenditure. These results suggest that the sympathetic nervous system could be targeted in the treatment of obesity-associated hypertension. Key Words: obesity Ⅲ hypertension Ⅲ autonomic nervous system Ⅲ sympathetic nervous system Ⅲ vascular resistance Ⅲ metabolism O besity affects Ͼ30% of the US population and is associated with increased mortality, mostly related to diabetes and cardiovascular events, 1 which translates to a reduction in life expectancy estimated to be 5 to 20 years. 2 Obesity is a precursor of hypertension, insulin resistance, dyslipidemia, and subclinical inflammation, a cluster known as the metabolic syndrome. The incidence of this disorder has increased dramatically in the past 2 decades with an age-adjusted prevalence of 27% among adults in the United States. 3 The mechanisms underlying hypertension in obesity are not completely understood. One of the prevailing theories, proposed by Landsberg, 4 states that obesity results in a compensatory sympathetic activation to drive thermogenesis and increase energy expenditure. In this scenario, obesityassociated hypertension may be an adverse result of sympathetic activation in an attempt to maintain energy balance. Indeed, there is increasing evidence that sympathetic nervous system activity is augmented in obesity. Sympathetic traffic to skeletal muscle reflecting baroreflex-modulated vasoconstrictive function is consistently increased in obesity and positively correlated with a...

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Abstract-Atomoxetine, a selective norepinephrine transporter blocker, could increase blood pressure by elevating norepinephrine concentration in peripheral sympathetic neurons. This effect may be masked in healthy subjects by central sympatholytic mechanisms. To test this hypothesis we studied the pressor effect of 18 mg of atomoxetine (pediatric dose) in 21 patients with damage of the central (10 subjects) and peripheral (11 subjects) autonomic nervous system. Atomoxetine was administered in a randomized, crossover, placebo-controlled fashion, and blood pressure and heart rate were measured at baseline and for 60 minutes after drug intake. Atomoxetine acutely increased seated and standing systolic blood pressure in patients with central autonomic failure by 54Ϯ26 (meanϮstandard deviation; Pϭ0.004) and 45Ϯ23 mm Hg (Pϭ0.016), respectively, as compared with placebo. At the end of the observation period the mean seated systolic blood pressure in the atomoxetine group was in the hypertensive range (149Ϯ26, range 113 to 209 mm Hg). However, in patients with peripheral autonomic failure, atomoxetine did not elicit a pressor response; seated and standing systolic blood pressure increased by 4Ϯ18 mm Hg (Pϭ0.695) and 0.6Ϯ8 mm Hg (Pϭ0.546) with atomoxetine as compared with placebo. In conclusion, atomoxetine induces a dramatic increase in blood pressure in patients with central autonomic failure even at very low doses. These findings suggest that a functional central sympatholytic pathway is essential to avoid hypertension in patients treated with this drug. Caution should be exercised when this medication is used in patients with milder form of autonomic impairment. Key Words: atomoxetine Ⅲ norepinephrine transporter protein Ⅲ hypertension Ⅲ autonomic nervous system diseases Ⅲ multiple system atrophy