Effects of patient-controlled abdominal compression on standing systolic blood pressure in adults with orthostatic hypotension

Treating Lows: Management of Orthostatic Hypotension

ABSTRACT

Orthostatic hypotension is a prevalent clinical condition, caused by heterogenous etiologies and associated with significant morbidity and mortality. Management is particularly challenging in patients with uncontrolled hypertension. A thorough assessment is needed to draw an appropriate management plan. The treatment aims to improve postural symptoms while minimizing side effects and reducing iatrogenic exacerbation of supine hypertension. A personalized management plan including rationalizing medications, patient education, identification, and avoidance of triggers, as well as nonpharmacological therapies such as compression devices, dietary modifications, and postural aids, make the first steps. Among pharmacological therapies, midodrine and fludrocortisone are the most prescribed and best studied; pyridostigmine, atomoxetine, and droxidopa are considered next. Yohimbine remains an investigational agent. A multidisciplinary team may be required in some patients with multiple comorbidities and polypharmacy. However, there is a lack of robust efficacy and safety evidence for all therapies. Building robust real-world and stratified clinical trials based on underlying pathophysiology may pave the way for further drug development and better clinical strategies and in this challenging unmet medical need.

A Safety-Centric Study on the Use of Inflatable Abdominal Binders for Managing Orthostatic Hypotension

The study focuses on the design and evaluation of inflatable abdominal binders for managing Orthostatic Hypotension. Orthostatic hypotension is a condition characterized by a significant drop in blood pressure when a person stands up, leading to symptoms such as dizziness, lightheadedness, and even fainting. The management of orthostatic hypotension typically involves a combination of pharmacological and non-pharmacological strategies. In the context of this research, an inflatable abdominal binder was designed, leveraging components that are not only economically viable but also easily obtainable. The evaluation of this device was conducted using a medical education manikin, specifically the CAE iStan manikin. The results demonstrated a correlation between the inflation values of the belt and the resulting pressure values exerted on the body. The general recommendation for an abdominal binder is to exert a pressure of 20-40 mmHg. Contrary to this, the study found that to maintain safe external pressure on the abdomen, the binder should not be inflated over 25 mmHg. This safety threshold was used as a reference point in the study, suggesting a potential need to revisit the standard recommendations for abdominal binder pressure. Further research is needed to assess the device's effectiveness in human subjects and to potentially redefine the safe and effective pressure range for abdominal binders.

Comparisons of heart rate variability responses to head-up tilt with and without abdominal and lower-extremity compression in healthy young individuals: a randomized crossover study

Introduction: Abdominal and lower-extremity compression techniques can help reduce orthostatic heart rate increases. However, the effects of body compression on the cardiac autonomic systems, which control heart rate, remain unclear. The primary objective of this study was to compare heart rate variability, a reflection of cardiac autonomic regulation, during a head-up tilt test with and without abdominal and lower-extremity compression in healthy young individuals. The secondary objective was to conduct a subgroup analysis, considering participant sex, and compare heart rate and heart rate variability responses to head-up tilt with and without compression therapy. Methods: In a randomized crossover design, 39 healthy volunteers (20 females, aged 20.9 ± 1.2 years) underwent two head-up tilt tests with and without abdominal and lower-extremity compression. Heart rate and heart rate variability parameters were measured during the head-up tilt tests, including the Stress Index, root mean square of successive differences between adjacent R-R intervals, low- and high-frequency components, and low-to-high frequency ratio. Results: Abdominal and lower-extremity compression reduced the orthostatic increase in heart rate (p < 0.001). The tilt-induced changes in heart rate variability parameters, except for the low-frequency component, were smaller in the compression condition than in the no-compression condition (p < 0.001). These results were consistent regardless of sex. Additionally, multiple regression analysis with potentially confounding variables revealed that the compression-induced reduction in Stress Index during the head-up tilt position was a significant independent variable for the compression-induced reduction in heart rate in the head-up tilt position (coefficient = 0.411, p = 0.025). Conclusion: Comparative analyses revealed that abdominal and lower-extremity compression has a notable impact on the compensatory sympathetic activation and vagal withdrawal typically observed during orthostasis, resulting in a reduction of the increase in heart rate. Furthermore, this decrease in heart rate was primarily attributed to the attenuation of cardiac sympathetic activity associated with compression. Our findings could contribute to the appropriate application of compression therapy for preventing orthostatic tachycardia. This study is registered with UMIN000045179.

COVID-19-Induced Postural Orthostatic Tachycardia Syndrome and Dysautonomia

Postural orthostatic tachycardia syndrome (POTS) is a disorder characterized by orthostatic intolerance and, by definition, includes clinical symptoms of lightheadedness, palpitations, and tremulousness among others. It is considered a relatively rare condition that affects approximately 0.2% of the general population, and it is estimated that between 500,000 to 1,000,000 individuals in the United States have the condition and recently has been linked to post-infectious (viral) etiologies. We present a case of a 53-year-old woman who was diagnosed with POTS following extensive autoimmune workup, who was also status post-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The post-coronavirus disease 2019 (COVID-19) cardiovascular autonomic dysfunction can affect global circulatory control, which describes increased heart rate even at resting states, and local circulatory disorders, such as coronary microvascular disease leading to vasospasm, as described by the patient's chest pain, and venous retention leading to pooling and reduced venous return after standing. Along with tachycardia with orthostatic intolerance, other symptoms can also accompany the syndrome. In the majority of patients, intravascular volume is reduced, leading to decreased venous return to the heart and causing reflex tachycardia and orthostatic intolerance. Management varies from lifestyle modifications to pharmacologic therapy, to which patients generally show a good response. POTS should be a differential on the cards, especially in patients post-COVID-19 infection, as these symptoms can be misdiagnosed as having psychological etiologies.

COVID-19 Induced Postural Orthostatic Tachycardia Syndrome (POTS): A Review

POTS (Postural Orthostatic Tachycardia Syndrome) is a multisystem disorder characterized by the abnormal autonomic response to an upright posture, causing orthostatic intolerance and excessive tachycardia without hypotension. Recent reports suggest that a significant percentage of COVID-19 survivors develop POTS within 6 to 8 months of infection. Prominent symptoms of POTS include fatigue, orthostatic intolerance, tachycardia, and cognitive impairment. The exact mechanisms of post-COVID-19 POTS are unclear. Still, different hypotheses have been given, including autoantibody production against autonomic nerve fibers, direct toxic effects of SARS-CoV-2, or sympathetic nervous system stimulation secondary to infection. Physicians should have a high suspicion of POTS in COVID-19 survival when presented with symptoms of autonomic dysfunction and should conduct diagnostic tests like the Tilt table and others to confirm it. The management of COVID-19-related POTS requires a comprehensive approach. Most patients respond to initial non-pharmacological options, but when the symptoms become more severe and they do not respond to the non-pharmacological approach, pharmacological options are considered. We have limited understanding and knowledge of post-COVID-19 POTS, and further research is warranted to improve our understanding and formulate a better management plan.

Management of Post-Viral Postural Orthostatic Tachycardia Syndrome With Craniosacral Therapy

Postural Orthostatic Tachycardia Syndrome (POTS) is a rare disorder of the autonomic nervous system. The number of people afflicted with this dysautonomia has increased dramatically in recent years due to the long-term effects of coronavirus disease (COVID-19); however, it is largely underdiagnosed. This case report is about a patient with post-viral neuropathic POTS. Neuropathic POTS is believed to be due to the damage of small nerve fibers that regulate the constriction of the blood vessels in the limb and abdomen, which leads to interference with vasoconstriction, and therefore causes tachycardia. Current literature emphasizes a treatment that is based on lifestyle modifications, such as increasing water and salt intake, and symptomatic pharmacological treatment. In this case, the 39-year-old male ptient was treated with osteopathic manipulative treatment (OMT), specifically the compression of the fourth ventricle (CV4), which has been associated with the production of hyperparasympathetic and anti-inflammatory effects and, hence, helps overcome the small-fiber neuropathy caused by the viral illness. We found that the CV4 technique led to the successful remission of the patient's symptoms. Therefore, we propose craniosacral therapy as a successful single management modality in patients with POTS.

Assessment of Abdominal Constrictor's Forces for Informing Computational Models of Orthostatic Hypotension

Orthostatic hypotension is defined as a sudden drop in blood pressure upon standing from a sitting or supine position. The prevalence of this condition increases exponentially with age. Nonpharmacological treatments are always the first step in the management of this condition, such as the use of an abdominal constriction belt to optimize the blood volume in the abdomen. A multitude of clinical trials have shown the efficacy of elastic abdominal compression as well as compression using an inflatable bladder; however, there are currently few accessible consumer products that can provide abdominal compression by using an inflatable bladder that ensures the correct amount of pressure is being exerted on the subject. This study serves to quantitatively analyze forces exerted in inflatable abdominal binders, a novel treatment that fits the criterion for a first-line intervention for orthostatic hypotension. Quantitative values aim to indicate both the anatomic regions of the body subjected to the highest pressure by abdominal binding. Quantitative values will also create a model that can correlate the amount of compression on the subject with varying levels of pressure in the inflatable bladder. Inflatable binders of varying levels of inflation are used and localized pressure values are recorded at 5 different vertical points along the abdomen in the midsternal line and midclavicular line, at the locations of the splanchnic veins. These findings indicate both the differences in the compressive force applied through elastic and inflatable binding, as well the regions on the abdomen subject to the highest force load during compression by an abdominal binder. A medical manikin called the iStan Manikin was used to collect data. The pressure values on a manikin were sensed by the JUZO pressure monitor, a special device created for the purpose of measuring the force under compressive garments. The pressure inside the inflatable bladder was extrapolated from a pressure gauge and the pressure was recorded at different degrees of inflation of the belt (mmHG) along two different areas of the abdomen, the midsternal line and the midclavicular line, to discern differences in force exerted on the patient (mmHG). Computational studies on the data from the JUZO pressure monitor as well as the data from the pressure gauge on the inflatable bladder allow us to create a model that can correlate the amount of pressure in the inflatable bladder to the amount of pressure exerted on the belt, thus making sure that the patient is not being harmed by the compressive force. The results of our study indicate that there is no significant difference between the pressures exerted on the midsternal and midclavicular lines of the body by the abdominal binder and that no significant difference exists between the external pressure measured by the inflatable belt and the pressure sensed on the human body by the JUZO sensor; however, we were able to extrapolate an equation that can tell the user the amount of pressure that is actually being exerted on them based on the pressure in the inflatable bladder as recorded by the gauge.

Effectiveness of non-pharmacological interventions to treat orthostatic hypotension in elderly people and people with a neurological condition: a systematic review

OBJECTIVE

The objective of this review was to summarize the best available evidence regarding the effectiveness of non-pharmacological interventions to treat orthostatic hypotension (OH) in elderly people and people with a neurological condition.

INTRODUCTION

Orthostatic hypotension is common in elderly people and people with a neurological condition and can interfere with or limit rehabilitation. Non-pharmacological interventions to treat OH could allow for longer and earlier mobilization, which is recommended in national clinical guidelines for rehabilitation in the acute or sub-acute phase following stroke or other neurological conditions.

INCLUSION CRITERIA

The review considered people aged 50 years and older, and people aged 18 years and elderly people with a neurological condition. Non-pharmacological interventions to treat OH included compression garments, neuromuscular stimulation, physical counter-maneuvers, aerobic or resistance exercises, sleeping with head tilted up, increasing fluid and salt intake, and timing and size of meals. The comparator was usual care, no intervention, pharmacological interventions, or other non-pharmacological interventions. Outcome measures included systolic blood pressure, diastolic blood pressure, heart rate, cerebral blood flow, observed/perceived symptoms, duration of standing or sitting in minutes, tolerance of therapy, functional ability, and adverse events/effects.

METHODS

Databases for published and unpublished studies available in English up to April 2018 with no lower date limit were searched. Critical appraisal was conducted using standardized instruments from JBI. Data were extracted using standardized tools designed for quantitative studies. Where appropriate, studies were included in a meta-analysis; otherwise, data were presented in a narrative form due to heterogeneity.

RESULTS

Forty-three studies - a combination of randomized controlled trials (n = 13), quasi-experimental studies (n = 28), a case control study (n = 1), and a case report (n = 1) - with 1069 participants were included. Meta-analyses of three interventions (resistance exercise, electrical stimulation, and lower limb compression bandaging) showed no significant effect of these interventions. Results from individual studies indicated physical maneuvers such as leg crossing, leg muscle pumping/contractions, and bending forward improved orthostatic hypotension. Abdominal compression improved OH. Sleeping with head up in combination with pharmacological treatment was more effective than sleeping with head up alone. Eating smaller, more frequent meals was effective. Drinking 480 mL of water increased blood pressure.

CONCLUSIONS

The review found mixed results for the effectiveness of non-pharmacological interventions to treat OH in people aged 50 years and older, and people with a neurological condition. There are several non-pharmacological interventions that may be effective in treating OH, but not all have resulted in clinically meaningful changes in outcome. Some may not be suitable for people with moderate to severe disability; therefore, it is important for clinicians to consider the patient's abilities and impairments when considering which non-pharmacological interventions to implement.

Autonomic Dysfunction in Parkinson's Disease

Recognition of the importance of nonmotor dysfunction as a component of Parkinson's disease has exploded over the past three decades. Autonomic dysfunction is a frequent and particularly important nonmotor feature because of the broad clinical spectrum it covers. Cardiovascular, gastrointestinal, urinary, sexual, and thermoregulatory abnormalities all can appear in the setting of Parkinson's disease. Cardiovascular dysfunction is characterized most prominently by orthostatic hypotension. Gastrointestinal dysfunction can involve virtually all levels of the gastrointestinal tract. Urinary dysfunction can entail either too frequent voiding or difficulty voiding. Sexual dysfunction is frequent and frustrating for both patient and partner. Alterations in sweating and body temperature are not widely recognized but often are present. Autonomic dysfunction can significantly and deleteriously impact quality of life for individuals with Parkinson's disease. Because effective treatment for many aspects of autonomic dysfunction is available, it is vitally important that assessment of autonomic dysfunction be a regular component of the neurologic history and exam and that appropriate treatment be initiated and maintained.

Addressing Orthostatic Hypotension in Heart Failure: Pathophysiology, Clinical Implications and Perspectives

Heart failure (HF)is a condition at high risk for orthostatic hypotension (OH)given the large proportion of patients at an advanced age and high burden of comorbidities contributing to OH, as well as a high prevalence of medications with neurovascular and volume modulating properties. Early identification of OH in HF seems to be crucial as OH can have an impact on patient symptoms, activity level and independence, be a marker of specific pathophysiological changes or be an indicator of need for personalized treatment. OH might contribute significantly to bad enough prognosis in HF, as, besides a risk of falls and cognitive decline, it was found to be associated with cardiovascular morbidity and mortality. In this review, we aimed to incentivize the routine use of orthostatic testing in HF, as well as stimulate future research in this field, which could lead to significant advances in the treatment and outcomes.

Splanchnic Venous Compression Enhances the Effects of ß-Blockade in the Treatment of Postural Tachycardia Syndrome

Background

Splanchnic venous pooling induced by upright posture triggers a compensatory increase in heart rate (HR), a response that is exaggerated in patients with postural tachycardia syndrome. To assess whether abdominal compression attenuates orthostatic tachycardia and improves symptoms, 18 postural tachycardia syndrome patients (32±2 years) were randomized to receive either abdominal compression (40 mm Hg applied with an inflatable binder ≈2 minutes before standing) or propranolol (20 mg) in a placebo‐controlled, crossover study.

Methods and Results

Systolic blood pressure, HR, and symptoms were assessed while seated and standing, before and 2 hours postdrug. As expected, propranolol decreased standing HR compared with placebo (81±2 versus 98±4 beats per minute; P<0.001) and was associated with lower standing systolic blood pressure (93±2 versus 100±2 mm Hg for placebo; P=0.002). Compression had no effect on standing HR (96±4 beats per minute) but increased standing systolic blood pressure compared with placebo and propranolol (106±2 mm Hg; P<0.01). Neither propranolol nor compression improved symptoms compared with placebo. In 16 patients we compared the combination of abdominal compression and propranolol with propranolol alone. The combination had no additional effect on standing HR (81±2 beats per minute for both interventions) but prevented the decrease in standing systolic blood pressure produced by propranolol (98±2 versus 93±2 mm Hg for propranolol; P=0.029), and significantly improved total symptom burden (−6±2 versus −1±2 for propranolol; P=0.041).

Conclusions

Splanchnic venous compression alone did not improve HR or symptoms but prevented the blood pressure decrease produced by propranolol. The combination was more effective in improving symptoms than either alone. Splanchnic venous compression can be a useful adjuvant therapy to propranolol in postural tachycardia syndrome.

Registration

URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT00262470.

Management of neurogenic orthostatic hypotension in the heart failure patient

Neurogenic orthostatic hypotension (nOH) is a common comorbidity in patients with neurodegenerative diseases. It is associated with an increased risk of falls, incident cardiovascular disease, and all-cause mortality. There are over 5 million individuals in the U.S. with heart failure (HF) with an associated 50% mortality rate at 5 years. The prevalence of nOH and HF increase with age and, as the population continues to age, will be increasingly common comorbid conditions. Thus, the effective management of these conditions has important implications for public health. The management of orthostatic hypotension in the context of congestive heart failure is challenging due to the fact that the fundamental principles of management of these disease states are in opposition to each other. In this review, we will discuss the principles of management of nOH and HF and outline strategies for the effective treatment of these comorbid conditions.

Combination non-pharmacologic intervention for orthostatic hypotension in older people: a phase 2 study

Background

orthostatic hypotension (OH) is highly prevalent in older populations and is associated with reduced quality of life and increased mortality. Although non-pharmacologic therapies are recommended first-line, evidence for their use is lacking.

Objective

determine the efficacy of combination non-pharmacologic therapy for OH in older people.

Methods

a total of 111 orthostatic BP responses were evaluated in this prospective phase 2 efficacy study in 37 older people (≥60 years) with OH. Primary outcome was the proportion of participants whose systolic BP drop improved by ≥10 mmHg. Secondary outcomes include standing BP and symptoms. Comparison is made to the response rate of the most efficacious single therapy (bolus water drinking 56%). Therapeutic combinations were composed of interventions with known efficacy and tolerability: Therapy A- Bolus water drinking + physical counter-manoeuvres (PCM); Therapy B- Bolus water drinking + PCM + abdominal compression.

Results

the response rate to therapy A was 38% (95% confidence interval – CI 24, 63), with standing systolic BP increasing by 13 mmHg (95% CI 4, 22). Therapy B was efficacious in 46% (95% CI 31, 62), increasing standing systolic BP by 20 mmHg (95% CI 12, 29). Neither therapy had a significant effect on symptoms. There were no adverse events.

Conclusions

in comparison to single therapy, there is little additional benefit to be gained from combination non-pharmacologic therapy. Focussing on single, efficacious therapies, such as bolus water drinking or PCM, should become standard first-line therapy.

Pure autonomic failure

In this chapter, we describe the history, presentation, diagnosis and treatment of pure autonomic failure (PAF). The pathology underlying this condition is thought to involve the deposition of alpha synuclein in the autonomic ganglia leading to diminished norepinephrine release and progressive autonomic dysfunction. We focus on various neurophysiological tests that may be used to evaluate the function of the peripheral autonomic nervous system including quantitative sudomotor axon reflex testing, thermoregulatory sweat testing, and others. These may help evaluate and diagnose various disorders of autonomic failure and neurogenic orthostatic hypotension including multiple system atrophy and Parkinson's disease dysautonomia. Management of PAF, including the therapeutic role of recent advances in pharmacologic treatment, is discussed.

Nonpharmacologic Management of Orthostatic Hypotension in Older People: A Systematic Review. The SENATOR ONTOP Series

OBJECTIVES

Nonpharmacologic therapies are often recommended as a first-line treatment for orthostatic hypotension (OH). However, the true effect of nonpharmacologic therapy remains unclear, particularly in the older population. We undertook a systematic review evaluating the efficacy of nonpharmacologic interventions in older people with OH to provide evidence-based recommendations.

DESIGN

Systematic review of systematic reviews.

SETTING AND PARTICIPANTS

MEDLINE, PubMed, EMBASE, and Cochrane Database of Systematic Reviews, CINHAL, and PsycINFO were searched up to June 2018. Two reviewers identified eligible systematic reviews from which primary studies were selected. We included both randomized and nonrandomized studies that evaluated any type of nonpharmacologic intervention and reported outcomes of change in postural drop in systolic blood pressure (SBP) and/or orthostatic symptoms measured using any validated instrument. The Cochrane risk of bias tool was used, with recommendations based on the GRADE approach.

RESULTS

Eleven trials were included. Meta-analysis of lower limb compression showed a reduction in the postural drop in SBP of 9.83 mmHg [95% confidence interval (CI) -12.56, -7.11], whereas abdominal compression showed a larger reduction in postural drop in SBP of 12.30 mmHg (95% CI -18.20, -6.39). Compression therapy was also beneficial in reducing OH symptoms. However, the quality of the evidence for compression therapy was very poor. One study each was identified for sleeping with head-up (SHU), home-based resistance training (HBRT), and multicomponent intervention but did not significantly reduce postural SBP drop. Bolus water drinking was effective in 1 study but the study was of low quality.

CONCLUSIONS/IMPLICATIONS

There is no high-quality evidence to recommend any of the nonpharmacologic therapies for the management of OH in older people. Yet, we make a weak recommendation for lower limb and abdominal compression therapy based on very low quality evidence. Large-scale trials are warranted in older people to substantiate the efficacy of nonpharmacologic therapies in OH.

Autonomic dysfunction: Diagnosis and management

The autonomic nervous system is designed to maintain physiologic homeostasis. Its widespread connections make it vulnerable to disruption by many disease processes including primary etiologies such as Parkinson's disease, multiple system atrophy, dementia with Lewy bodies, and pure autonomic failure and secondary etiologies such as diabetes mellitus, amyloidosis, and immune-mediated illnesses. The result is numerous symptoms involving the cardiovascular, gastrointestinal, and urogenital systems. Patients with autonomic dysfunction (AUD) often have peripheral and/or cardiac denervation leading to impairment of the baroreflex, which is known to play a major role in determining hemodynamic outcome during orthostatic stress and low cardiac output states. Heart rate and plasma norepinephrine responses to orthostatic stress are helpful in diagnosing impairment of the baroreflex in patients with orthostatic hypotension (OH) and suspected AUD. Similarly, cardiac sympathetic denervation diagnosed with MIBG scintigraphy or ¹⁸F-DA PET scanning has also been shown to be helpful in distinguishing preganglionic from postganglionic involvement and in diagnosing early stages of neurodegenerative diseases. In this chapter, we review the causes of AUD, the pathophysiology and resulting cardiovascular manifestations with emphasis on the diagnosis and treatment of OH.

Orthostatic hypotension for the cardiologist

PURPOSE OF REVIEW

Orthostatic hypotension is a phenomenon commonly encountered in a cardiologist's clinical practice that has significant diagnostic and prognostic value for a cardiologist. Given the mounting evidence associating cardiovascular morbidity and mortality with orthostatic hypotension, cardiologists will play an increasing role in treating and managing patients with orthostatic hypotension.

RECENT FINDINGS

The American College of Cardiology, American Heart Association, and Heart Rhythm Society recently published consensus guidelines on the diagnosis, treatment, and management of syncope and their instigators, including orthostatic hypotension. Additionally, consensus guidelines have also been recently updated, reinforcing the universal definition orthostatic hypotension and its closely associated pathologies. Finally, the United States Food and Drug Administration (FDA) recently approved droxidopa, a synthetic oral norepinephrine prodrug, in 2014 for the treatment of neurogenic orthostatic hypotension (nOH), and it represents a well tolerated, effective, and easy to use intervention for nOH. This represents only the second drug approved by the FDA for orthostatic hypotension, the first being midodrine in 1986. A handful of smaller head-to-head studies have pitted not only pharmacologic agents to one another but also nonpharmacologic interventions to pharmacologic agents. Additionally, recent studies have also reported on more convenient screening tools for orthostatic hypotension.

SUMMARY

Though there have been many advances in the management of orthostatic hypotension, nOH remains a chronic, debilitating, and often progressively fatal condition. Cardiologists can play a very important role in optimizing hemodynamics in this patient population to improve quality of life and minimize cardiovascular risk.

Evidence-based treatment of neurogenic orthostatic hypotension and related symptoms

Neurogenic orthostatic hypotension, postprandial hypotension and exercise-induced hypotension are common features of cardiovascular autonomic failure. Despite the serious impact on patient’s quality of life, evidence-based guidelines for non-pharmacological and pharmacological management are lacking at present. Here, we provide a systematic review of the literature on therapeutic options for neurogenic orthostatic hypotension and related symptoms with evidence-based recommendations according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Patient’s education and non-pharmacological measures remain essential, with strong recommendation for use of abdominal binders. Based on quality of evidence and safety issues, midodrine and droxidopa reach a strong recommendation level for pharmacological treatment of neurogenic orthostatic hypotension. In selected cases, a range of alternative agents can be considered (fludrocortisone, pyridostigmine, yohimbine, atomoxetine, fluoxetine, ergot alkaloids, ephedrine, phenylpropanolamine, octreotide, indomethacin, ibuprofen, caffeine, methylphenidate and desmopressin), though recommendation strength is weak and quality of evidence is low (atomoxetine, octreotide) or very low (fludrocortisone, pyridostigmine, yohimbine, fluoxetine, ergot alkaloids, ephedrine, phenylpropanolamine, indomethacin, ibuprofen, caffeine, methylphenidate and desmopressin). In case of severe postprandial hypotension, acarbose and octreotide are recommended (strong recommendation, moderate level of evidence). Alternatively, voglibose or caffeine, for which a weak recommendation is available, may be useful.

Pure Autonomic Failure

Pure autonomic failure (PAF) is a rare sporadic neurodegenerative autonomic disorder characterized by slowly progressive pan autonomic failure without other features of neurologic dysfunctions. The main clinical symptoms result from neurogenic orthostatic hypotension and urinary and gastrointestinal autonomic dysfunctions. Autonomic failure in PAF is caused by neuronal degeneration of pre- and postganglionic sympathetic and parasympathetic neurons in the thoracic spinal cord and paravertebral autonomic ganglia. The presence of Lewy bodies and α-synuclein deposits in these neural structures suggests that PAF is one of Lewy body synucleinopathies, examples of which include multiple system atrophy, Parkinson disease, and Lewy body disease. There is currently no specific treatment to stop progression in PAF. Management of autonomic symptoms is the mainstay of treatment and includes management of orthostatic hypotension and supine hypertension. The prognosis for survival of PAF is better than for the other synucleinopathies.

[Orthostatic hypotension; that great unknown]

Orthostatic hypotension is an anomaly of growing interest in scientific research. Although certain neurogenic diseases are associated with this phenomenon, it can also be associated with non-neurological causes. Although orthostatic hypotension is defined by consensus as a decrease in the systolic blood pressure of at least 20mmHg, or a decrease in diastolic blood pressure of at least 10mmHg, within 3min of standing, the studies differ on how to diagnose it. Orthostatic hypotension is associated with certain cardiovascular risk factors and with drug treatment, but the results are contradictory. The purpose of this review is to update the knowledge about orthostatic hypotension and its treatment, as well as to propose a method to standardise its diagnosis.

Efficacy of Servo-Controlled Splanchnic Venous Compression in the Treatment of Orthostatic Hypotension: A Randomized Comparison With Midodrine

Splanchnic venous pooling is a major hemodynamic determinant of orthostatic hypotension, but is not specifically targeted by pressor agents, the mainstay of treatment. We developed an automated inflatable abdominal binder that provides sustained servo-controlled venous compression (40 mm Hg) and can be activated only on standing. We tested the efficacy of this device against placebo and compared it to midodrine in 19 autonomic failure patients randomized to receive either placebo, midodrine (2.5-10 mg), or placebo combined with binder on separate days in a single-blind, crossover study. Systolic blood pressure (SBP) was measured seated and standing before and 1-hour post medication; the binder was inflated immediately before standing. Only midodrine increased seated SBP (31±5 versus 9±4 placebo and 7±5 binder, P=0.003), whereas orthostatic tolerance (defined as area under the curve of upright SBP [AUCSBP]) improved similarly with binder and midodrine (AUCSBP, 195±35 and 197±41 versus 19±38 mm Hg×minute for placebo; P=0.003). Orthostatic symptom burden decreased with the binder (from 21.9±3.6 to 16.3±3.1, P=0.032) and midodrine (from 25.6±3.4 to 14.2±3.3, P<0.001), but not with placebo (from 19.6±3.5 to 20.1±3.3, P=0.756). We also compared the combination of midodrine and binder with midodrine alone. The combination produced a greater increase in orthostatic tolerance (AUCSBP, 326±65 versus 140±53 mm Hg×minute for midodrine alone; P=0.028, n=21) and decreased orthostatic symptoms (from 21.8±3.2 to 12.9±2.9, P<0.001). In conclusion, servo-controlled abdominal venous compression with an automated inflatable binder is as effective as midodrine, the standard of care, in the management of orthostatic hypotension. Combining both therapies produces greater improvement in orthostatic tolerance.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00223691.