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Hosseini-Dastgerdi H, Pourshanazari AA, Nematbakhsh M. The role of Mas receptor on renal hemodynamic responses to angiotensin II administration in chronic renal sympathectomized male and female rats. Res Pharm Sci 2023; 18:489-504. [PMID: 37842515 PMCID: PMC10568965 DOI: 10.4103/1735-5362.383705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/14/2023] [Accepted: 05/09/2023] [Indexed: 10/17/2023] Open
Abstract
Background and purpose Renal hemodynamics is influenced by renal sympathetic nerves and the renin-angiotensin system. On the other hand, renal sympathetic denervation impacts kidney weight by affecting renal hemodynamics. The current study evaluated the role of the Mas receptor on renal hemodynamic responses under basal conditions and in response to angiotensin II (Ang II) in chronic renal sympathectomy in female and male rats. Experimental approach Forty-eight nephrectomized female and male rats were anesthetized and cannulated. Afterward, the effect of chronic renal sympathectomy was investigated on hemodynamic parameters such as renal vascular resistance (RVR), mean arterial pressure (MAP), and renal blood flow (RBF). In addition, the effect of chronic sympathectomy on kidney weight was examined. Findings/Results Chronic renal sympathectomy increased RVR and subsequently decreased RBF in both sexes. Renal perfusion pressure also increased after sympathectomy in male and female rats, while MAP did not change, significantly. In response to the Ang II injection, renal sympathectomy caused a greater decrease in RBF in all experimental groups, while it did not affect the MAP response. In addition, chronic sympathectomy increased left kidney weight in right nephrectomized rats. Conclusion and implications Chronic renal sympathectomy changed systemic/renal hemodynamics in baseline conditions and only renal hemodynamics in response to Ang II administration. Moreover, chronic sympathectomy increased compensatory hypertrophy in nephrectomized rats. These changes are unaffected by gender difference and Mas receptor blocker.
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Affiliation(s)
- Hajaralsadat Hosseini-Dastgerdi
- Water and Electrolytes Research Center, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
- Department of Physiology, Medical School, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | - Ali-Asghar Pourshanazari
- Department of Physiology, Medical School, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | - Mehdi Nematbakhsh
- Water and Electrolytes Research Center, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
- Department of Physiology, Medical School, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
- Isfahan MN Institute of Basic and Applied Sciences Research, Isfahan, I.R. Iran
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COVID-19 Induced Postural Orthostatic Tachycardia Syndrome (POTS): A Review. Cureus 2023; 15:e36955. [PMID: 37009342 PMCID: PMC10065129 DOI: 10.7759/cureus.36955] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2023] [Indexed: 04/03/2023] Open
Abstract
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.
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Veazie S, Peterson K, Ansari Y, Chung KA, Gibbons CH, Raj SR, Helfand M. Fludrocortisone for orthostatic hypotension. Cochrane Database Syst Rev 2021; 5:CD012868. [PMID: 34000076 PMCID: PMC8128337 DOI: 10.1002/14651858.cd012868.pub2] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Orthostatic hypotension is an excessive fall in blood pressure (BP) while standing and is the result of a decrease in cardiac output or defective or inadequate vasoconstrictor mechanisms. Fludrocortisone is a mineralocorticoid that increases blood volume and blood pressure. Fludrocortisone is considered the first- or second-line pharmacological therapy for orthostatic hypotension alongside mechanical and positional measures such as increasing fluid and salt intake and venous compression methods. However, there has been no Cochrane Review of the benefits and harms of this drug for this condition. OBJECTIVES To identify and evaluate the benefits and harms of fludrocortisone for orthostatic hypotension. SEARCH METHODS We searched the following databases on 11 November 2019: Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL. We also searched trials registries. SELECTION CRITERIA We included all studies evaluating the benefits and harms of fludrocortisone compared to placebo, another drug for orthostatic hypotension, or studies without comparators, including randomized controlled trials (RCTs), quasi-RCTs and observational studies. We included studies in people with orthostatic hypotension due to a chronic peripheral neuropathy, a central autonomic neuropathy, or autonomic failure from other causes, but not medication-induced orthostatic hypotension or orthostatic hypotension from acute volume depletion or blood loss. DATA COLLECTION AND ANALYSIS We used Cochrane methodological procedures for most of the review. We developed and used a tool to prioritize observational studies that offered the best available evidence where there are gaps in the evidence from RCTs. We assessed the certainty of evidence for fludrocortisone versus placebo using GRADE. MAIN RESULTS We included 13 studies of 513 participants, including three cross-over RCTs and 10 observational studies (three cohort studies, six case series and one case-control study). The included RCTs were small (total of 28 participants in RCTs), short term (two to three weeks), only examined fludrocortisone for orthostatic hypotension in people with two conditions (diabetes and Parkinson disease), and had variable risk of bias (two had unclear risk of bias and one had low risk of bias). Heterogeneity in participant populations, comparators and outcome assessment methods prevented meta-analyses of the RCTs. We found very low-certainty evidence about the effects of fludrocortisone versus placebo on drop in BP in people with diabetes (-26 mmHg versus -39 mmHg systolic; -7 mmHg versus -11 mmHg diastolic; 1 cross-over study, 6 participants). For people with Parkinson disease, we found very-low certainty evidence about the effects of fludrocortisone on drop in BP compared to pyridostigmine (-14 mmHg versus -22.1 mmHg diastolic; P = 0.036; 1 cross-over study, 9 participants) and domperidone (no change after treatment in either group; 1 cross-over study, 13 participants). For orthostatic symptoms, we found very low-certainty evidence for fludrocortisone versus placebo in people with diabetes (4 out of 5 analyzed participants had improvements in orthostatic symptoms, 1 cross-over study, 6 participants), for fludrocortisone versus pyridostigmine in people with Parkinson disease (orthostatic symptoms unchanged; 1 cross-over study, 9 participants) or fludrocortisone versus domperidone (improvement to 6 for both interventions on the Composite Autonomic Symptom Scale-Orthostatic Domain (COMPASS-OD); 1 cross-over study, 13 participants). Evidence on adverse events was also very low-certainty in both populations, but indicated side effects were minimal. Observational studies filled some gaps in evidence by examining the effects in larger groups of participants, with more diverse conditions, over longer periods of time. One cohort study (341 people studied retrospectively) found fludrocortisone may not be harmful in the long term for familial dysautonomia. However, it is unclear if this translates to long-term improvements in BP drop or a meaningful improvement in orthostatic symptoms. AUTHORS' CONCLUSIONS The evidence is very uncertain about the effects of fludrocortisone on blood pressure, orthostatic symptoms or adverse events in people with orthostatic hypotension and diabetes or Parkinson disease. There is a lack of information on long-term treatment and treatment of orthostatic hypotension in other disease states. There is a need for standardized reporting of outcomes and for standardization of measurements of blood pressure in orthostatic hypotension.
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Affiliation(s)
- Stephanie Veazie
- Scientific Resource Center, VA Portland Health Care System, Portland, Oregon, USA
| | - Kim Peterson
- Evidence-based Synthesis Program Coordinating Center, VA Portland Health Care System, Portland, Oregon, USA
| | - Yasmin Ansari
- Internal Medicine and Geriatrics, Oregon Health & Science University, Portland, Oregon, USA
| | - Kathryn A Chung
- Neurology, Oregon Health & Science University, Portland, Oregon, USA
| | | | - Satish R Raj
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, Calgary, Canada
| | - Mark Helfand
- Medicine, Medical Informatics & Clinical Epidemiology, Oregon Health Sciences University, Portland, Oregon, USA
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4
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Dixon DD, Muldowney JAS. Management of neurogenic orthostatic hypotension in the heart failure patient. Auton Neurosci 2020; 227:102691. [PMID: 32559655 DOI: 10.1016/j.autneu.2020.102691] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 03/25/2020] [Accepted: 05/19/2020] [Indexed: 12/11/2022]
Abstract
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.
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Affiliation(s)
- Debra D Dixon
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - James A S Muldowney
- Division of Cardiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States of America.
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5
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Cheshire WP. Chemical pharmacotherapy for the treatment of orthostatic hypotension. Expert Opin Pharmacother 2018; 20:187-199. [DOI: 10.1080/14656566.2018.1543404] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Abstract
Background orthostatic hypotension (OH) is a common disabling condition associated with increased morbidity and mortality. Much of the evidence available is derived from younger populations with chronic neurological disease leading to uncertainty for the diagnosis and management of older people. Objective to provide an overview of recent and emerging evidence for the diagnosis, management and prognosis of OH in older persons. Methods a narrative review of recent studies, emerging therapies and relevant regulatory updates. Findings revisions to the diagnostic criteria for OH include the duration of the blood pressure drop, specific criteria for initial and delayed OH and OH with hypertension. Non-drug therapies remain the first-line treatment option and Comprehensive Geriatric Assessment appears to result in lower rates of OH. Recent evidence concerning withdrawal of causative medication is inconsistent. Midodrine has recently become the only licenced medication for OH in the UK. Other emerging treatments include atomoxetine and droxidopa but these require further evaluation. Many other agents may be used but are not supported by high-quality evidence. The increase in mortality associated with OH is less apparent in older people. Summary OH remains common in older people, the new diagnostic criteria address some of the previous uncertainty but evidence concerning withdrawal of antihypertensives is conflicting. Midodrine is now the only licenced medication for OH in the UK, but non-drug therapies remain first line and fludrocortisone may be considered before midodrine. We may see other agents such as droxidopa becoming increasingly used over the coming years.
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Affiliation(s)
- James Frith
- Newcastle University-Institute of Cellular Medicine, Newcastle upon Tyne NE1 7RU, United Kingdom of Great Britain and Northern Ireland
- The Newcastle upon Tyne Hospitals NHS Foundation Trust-Falls and Syncope Service, Newcastle upon Tyne, United Kingdom of Great Britain and Northern Ireland
| | - Steve W Parry
- Newcastle University-Institute of Cellular Medicine, Newcastle upon Tyne NE1 7RU, United Kingdom of Great Britain and Northern Ireland
- The Newcastle upon Tyne Hospitals NHS Foundation Trust-Falls and Syncope Service, Newcastle upon Tyne, United Kingdom of Great Britain and Northern Ireland
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Bruce BK, Harrison TE, Bee SM, Luedtke CA, Porter CBJ, Fischer PR, Hayes SE, Allman DA, Ale CM, Weiss KE. Improvement in Functioning and Psychological Distress in Adolescents With Postural Orthostatic Tachycardia Syndrome Following Interdisciplinary Treatment. Clin Pediatr (Phila) 2016; 55:1300-1304. [PMID: 26983448 DOI: 10.1177/0009922816638663] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Significant functional impairment and psychological distress have been observed in adolescent patients with postural orthostatic tachycardia syndrome (POTS). Interdisciplinary rehabilitation programs have been shown to be beneficial in the treatment of chronic pain in adults and adolescents. Only preliminary data have examined interdisciplinary rehabilitation efforts in patients with POTS. This study evaluated the impact of an interdisciplinary rehabilitation program on the functional impairment and psychological distress in 33 adolescents diagnosed with POTS. Patients included in the study were adolescents ages 11 to 18 diagnosed with POTS. Measures completed at admission and discharge from the program included the Functional Disability Index, Center for Epidemiological Studies-Depression-Child scale, and the Pain Catastrophizing Scale for Children. After participation in the 3-week program, adolescents with POTS demonstrated a significant increase in overall functional ability and significant reductions in depression and catastrophizing.
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9
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Sidhu B, Obiechina N, Rattu N, Mitra S. Postural orthostatic tachycardia syndrome (POTS). BMJ Case Rep 2013; 2013:bcr2013201244. [PMID: 24042210 PMCID: PMC3794314 DOI: 10.1136/bcr-2013-201244] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous group of conditions characterised by autonomic dysfunction and an exaggerated sympathetic response to assuming an upright position. Up till recently, it was largely under-recognised as a clinical entity. There is now consensus about the definition of POTS as a greater than 30/min heart rate increase on standing from a supine position (greater than 40/min increase in 12-19-year-old patients) or an absolute heart rate of greater than 120/min within 10 min of standing from a supine position and in the absence of hypotension, arrhythmias, sympathomimetic drugs or other conditions that cause tachycardia. We present two cases of POTS, followed by a discussion of its pathogenesis, pathophysiology, epidemiology and management.
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Affiliation(s)
- Bharat Sidhu
- Department of General Medicine, NHS, Birmingham, West Midlands, UK
| | - Nonyelum Obiechina
- Department of Elderly Care & General Medicine, Queens Hospital Burton, Birmingham, UK
| | - Noman Rattu
- Department of Elderly Care & General Medicine, Queens Hospital Burton, Birmingham, UK
| | - Shanta Mitra
- Department of General Medicine, Queens Hospital Burton, Birmingham, UK
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10
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Abstract
Severe autonomic failure occurs in approximately 1 in 1,000 people. Such patients are remarkable for the striking and sometimes paradoxic responses they manifest to a variety of physiologic and pharmacologic stimuli. Orthostatic hypotension is often the finding most commonly noted by physicians, but a myriad of additional and less understood findings also occur. These findings include supine hypertension, altered drug sensitivity, hyperresponsiveness of blood pressure to hypo/hyperventilation, sleep apnea, and other neurologic disturbances. In this article the authors will review the clinical pathophysiology that underlies autonomic failure, with a particular emphasis on those aspects most relevant to the care of such patients in the perioperative setting. Strategies used by clinicians in diagnosis and treatment of these patients, and the effect of these interventions on the preoperative, intraoperative, and postoperative care that these patients undergo is a crucial element in the optimized management of care in these patients.
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Abstract
OBJECTIVES To demonstrate clinical evidence that vestibular symptomatology can occur in relation to autonomic dysfunction. Characterization of clinical findings and treatment response would then allow autonomic related vertigo to be differentiated from other vertiginous conditions that present in a like manner. STUDY DESIGN This was a retrospective review of 113 patients that described symptoms consistent with spontaneous, rotational vertigo and autonomic dysfunction. METHODS Vestibular, otologic, and autonomic symptoms are presented along with the results of audiologic, orthostatic, and autonomic testing. Medical management included fluid loading, dietary changes, exercise, and patient education. Treatment results were analyzed according to the effectiveness in control of vestibular and otologic symptoms. Results were compared with a control group that demonstrated a similar vestibular and otologic presentation without autonomic symptomatology. RESULTS All patients described spontaneous, rotational vertigo, with complete or substantial vertigo control obtained in 93 (85%) of 110 patients. Postural vertigo and distinct lightheadedness were also documented in 53% and 97% of cases, respectively. Vertigo failed to improve or worsened with prior treatment of low sodium diet or diuretic in 53 (91%) of 58 cases. Vertigo improvement was subsequently achieved in 48 (86%) of 56 cases with an autonomic treatment regimen. Long-term vertigo control was obtained in 56 (88%) of 64 patients followed for at least 18 months. Tinnitus was reported in 97 (86%) patients, aural fullness in 93 (82%) patients, and subjective hearing loss (HL) in 46 (41%) of 111 cases. Bilateral tinnitus and aural fullness occurred in 65% and 63%, respectively. Tinnitus improved with treatment in 56 (67%) of 84 patients, whereas aural fullness improved in 59 (74%) of 80 patients. Autonomic symptoms included palpitations in 103 (91%) patients, chronic fatigue in 102 (90%) patients, cold extremities in 91 (81%) patients, and previous fainting in 72 (64%) patients. A history of mitral valve prolapse was documented in 51 (45%) of cases and demonstrated with echocardiogram in 68 (93%) of the 73 patients tested. Audiologic testing was normal in 104 (95%) of 109 patients, and electrocochleography was abnormal in 42 (40%) of 105 patients. Orthostatic blood pressure and heart rate testing met the criteria for orthostatic hypotension in 16 (15%) of 104 patients. Autonomic testing was obtained in 34 cases, with orthostatic intolerance demonstrated in 33 (97%) patients and orthostatic hypotension demonstrated in 13 (38%) patients. Overall, orthostatic hypotension was documented through combined testing results in 23 (21%) of 107 patients. Vertigo was reproduced during autonomic testing in 17 (77%) of 22 patients, and otologic symptoms were reproduce in 9 (47%) of 19 patients. Comparison of the study population with a control group without autonomic symptoms revealed statistically significant differences in orthostatic testing and treatment results. There was no statistical difference noted in findings between patients of this study that demonstrated or failed to demonstrate orthostatic hypotension. CONCLUSIONS There is a subgroup of patients with spontaneous vertigo who also demonstrate symptoms and findings consistent with poor autonomic regulation. These patients report vertigo improvement with a treatment strategy that aims to improve autonomic dysfunction through expansion of effective circulating volume. Clinical findings and treatment results of this study suggest an underlying autonomic influence in the production of vertigo and otologic symptoms.
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Affiliation(s)
- Dennis G Pappas
- Pappas Ear Clinic, 2937 7th Avenue South, Birmingham, AL 35233, USA.
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Kearney F, Moore A. Pharmacological options in the management of orthostatic hypotension in older adults. Expert Rev Cardiovasc Ther 2010; 7:1395-400. [PMID: 19900022 DOI: 10.1586/erc.09.130] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Orthostatic hypotension (OH) is a common disorder in older adults with potentially serious clinical consequences. Understanding the key underlying pathophysiological processes that predispose individuals to OH is essential when making treatment decisions for this group of patients. In this article, we discuss the key antihypotensive agents used in the management of OH in older adults. Commonly, midodrine is used as a first-line agent, given its supportive data in randomized, controlled trials. Fludrocortisone has been evaluated in open-label trials and has long-established usage in clinical practice. Other agents are available and in clinical use, either alone or in combination, but larger randomized trial evaluations are yet to be published. It is important to bear in mind that a patient may be taking medications that predispose to or exacerbate the symptoms of OH. Withdrawal of such medications, where possible, should be considered before commencing other pharmacological agents that attenuate the symptoms of OH.
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Affiliation(s)
- Fiona Kearney
- Department of Geriatric Medicine, Beaumont Hospital, Dublin 9, Ireland
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Carew S, Connor MO, Cooke J, Conway R, Sheehy C, Costelloe A, Lyons D. A review of postural orthostatic tachycardia syndrome. Europace 2009; 11:18-25. [PMID: 19088364 DOI: 10.1093/europace/eun324] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
A 21-year-old female reports an 18-month history of light-headedness on standing. This is often associated with palpitations and a feeling of intense anxiety. She has had two black-outs in the past 12 months. She is not taking any regular medications. Her supine blood pressure was 126/84 mmHg with a heart rate of 76 bpm, and her upright blood pressure was 122/80 mmHg with a heart rate of 114 bpm. A full system examination was otherwise normal. She had a 12-lead electrocardiogram performed which was unremarkable. She was referred for head-up tilt testing. She was symptomatic during the test and lost consciousness at 16 min. Figure 1 summarizes her blood pressure and heart rate response to tilting. A diagnosis of postural orthostatic tachycardia syndrome with overlapping vasovagal syncope was made.
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Affiliation(s)
- Sheila Carew
- Blood Pressure Unit, Mid Western Regional Hospital, Limerick, Ireland
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Abstract
BACKGROUND The effects of midodrine on chronic hypotension in hemodialysis (HD) patients have not been well investigated. METHODS We evaluated midodrine's effect on autonomic function and hemodynamics in 12 HD patients who had chronic systolic blood pressure less than 100 mm Hg. Midodrine (5.0 mg) twice a day was given for 4 weeks. Another 12 age- and sex-matched HD patients with normotension were selected as a control group. Autonomic function tests included the heart-rate responses to the Valsalva maneuver and 30:15 ratio as well as supine and standing blood pressure (BP) and sustained hand-grip test. Hemodynamic changes included 24-hour blood pressure, cardiac output, total peripheral resistance (TPR), and plasma renin and aldosterone concentrations. RESULTS Compared with the control subjects, HD patients with chronic hypotension had more severe autonomic dysfunction and significantly lower TPR. After 4 weeks of midodrine therapy, sympathetic function (orthostatic and hand-grip tests) improved in conjunction with significant increases in mean arterial pressure (MAP) (79.5 +/- 4.9 to 85.0 +/- 5.1 mm Hg, P < 0.05) and TPR (768 +/- 37 versus 1097 +/- 72 dyne/sec/cm-5, P < 0.01) despite no significant change in Valsalva ratio, 30:15 ratio, and cardiac output. MAP changes were positively correlated with TPR changes (r = 0.82, P < 0.001). Supine plasma renin activity was significantly increased. In addition, MAP during HD was also significantly increased during midodrine therapy. CONCLUSIONS Midodrine improves chronic hypotension in HD patients by modulating autonomic function and its direct effects on peripheral vessels.
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Affiliation(s)
- Yuh-Feng Lin
- Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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Frishman WH, Azer V, Sica D. Drug treatment of orthostatic hypotension and vasovagal syncope. HEART DISEASE (HAGERSTOWN, MD.) 2003; 5:49-64. [PMID: 12549988 DOI: 10.1097/01.hdx.0000050416.53995.43] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Orthostatic hypotension is a common problem, estimated to occur in 5 out of every 1000 individuals and in as many as 7% to 17% of patients in an acute care setting. Moreover, orthostatic hypotension may be more prominent in elderly patients due to the increased intake of vasoactive medications and concomitant decrease in physiologic function, such as baroreceptor sensitivity, often seen with aging. Orthostatic hypotension is a fall in blood pressure on assuming an upright position. Absolute cutoffs for the drop in blood pressure are often difficult to determine because different patients exhibit varying degrees of tolerance to falls in blood pressure. Therefore, strict numerical criteria may lead to underdiagnosis and improper intervention. A thorough review of patient symptomatology combined with appropriate clinical tests should be employed to narrow the vast differential diagnosis and pinpoint the etiology. The fall in blood pressure seen in orthostatic hypotension results from the inability of the autonomic nervous system to adequately compensate for the 500 mL blood that is estimated to pool in the lower extremities on assuming an upright posture. The decrease in venous return results in a concomitant decrease in cardiac output and thus hypoperfusion of the cerebral circulation, possibly resulting in syncope or various other symptoms. A complete investigation should consider hypovolemia, removal of offending medications, primary autonomic disorders, secondary autonomic disorders and, of course, vasovagal syncope, the most common cause of syncope. Although further research is still necessary to rectify the disease process responsible for orthostatic hypotension, patients suffering from this disorder can effectively be treated through a combination of nonpharmacologic treatment, pharmacologic treatment and patient education. Agents such as fludrocortisone, midodrine and erythropoietin show promising results as therapeutic adjuncts. Treatment for recurrent vasovagal syncope includes increased salt intake, and various drug treatments, most of which are still under investigation.
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Affiliation(s)
- William H Frishman
- Department of Medicine, New York Medical College/Westchester Medical Center, Valhalla, New York 10595, USA.
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Chelimsky G, Boyle JT, Tusing L, Chelimsky TC. Autonomic abnormalities in children with functional abdominal pain: coincidence or etiology? J Pediatr Gastroenterol Nutr 2001; 33:47-53. [PMID: 11479407 DOI: 10.1097/00005176-200107000-00008] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND There is increasing evidence that autonomic neuropathies may adversely affect gastrointestinal motility by involving the extrinsic nerves of the gut. The authors' hypothesize that functional abdominal pain in children is associated with generalized autonomic dysfunction. METHODS The authors performed detailed autonomic testing in eight patients with functional abdominal pain, including deep breathing, Valsalva, tilting (to assess parasympathetic and sympathetic adrenergic function), and axon-reflex function and thermoregulatory sweat testing to assess sympathetic cholinergic function. Patients also completed a questionnaire regarding other autonomic symptoms. RESULTS Results of autonomic testing were abnormal in seven patients. Parasympathetic function was normal in all, and the abnormalities were restricted to sympathetic cardiac, vasomotor, and sudomotor function. Abnormal results of axon-reflex testing in six were consistent with peripheral nervous system dysfunction. Five had decreased sweating over the abdomen, determined by thermoregulatory sweat testing. Five eight had nongastrointestinal autonomic symptoms, primarily palpitations and flushing. CONCLUSIONS Functional abdominal pain in the current patients is associated with generalized dysfunction of the autonomic nervous system. This dysfunction can be peripheral or central in different individuals but seems to be restricted to the sympathetic branch. The known function of the sympathetic nervous system as the motility "brake" suggests that pain could be a manifestation of unmodulated peristalsis, resulting in abdominal cramps.
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Affiliation(s)
- G Chelimsky
- Division of Pediatric Gastroenterology and Nutrition, Rainbow Babies and Children's Hospital and Case Western Reserve University, 11100 Euclid Avenue, Cleveland, Ohio 44106, U.S.A
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Boehm KE, Morris EJ, Kip KT, Karas B, Grubb BP. Diagnosis and management of neurally mediated syncope and related conditions in adolescents. J Adolesc Health 2001; 28:2-9. [PMID: 11137899 DOI: 10.1016/s1054-139x(00)00153-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- K E Boehm
- Division of Adolescent Medicine, Department of Pediatrics, Medical College of Ohio, Mercy Children's Hospital, Toledo, Ohio 43608, USA.
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Karas B, Grubb BP, Boehm K, Kip K. The postural orthostatic tachycardia syndrome: a potentially treatable cause of chronic fatigue, exercise intolerance, and cognitive impairment in adolescents. Pacing Clin Electrophysiol 2000; 23:344-51. [PMID: 10750135 DOI: 10.1111/j.1540-8159.2000.tb06760.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Head upright tilt table testing has become an accepted method to measure an individual's predisposition to autonomically mediated periods of hypotension and bradycardia severe enough to cause frank syncope. At the same time it has become increasingly apparent that less profound falls in blood pressure, while not sufficient to result in loss of consciousness, may cause symptoms such as near syncope, vertigo, and dizziness. We describe a subgroup of adolescents that have a mild form of autonomic dysfunction that exhibit disabling symptoms such as postural tachycardia and palpitations, extreme fatigue, lightheadedness, exercise intolerance, and cognitive impairment. During baseline tilt table testing at a 70 degrees angle, these patients demonstrated a heart rate increase of > or = 30 beats/min (or a maximum heart rate of > or = 120 beats/min) within the first 10 minutes upright (not associated with profound hypotension), which reproduced their clinical symptom complex. Similar observations have been made in the adult population and has been termed the postural orthostatic tachycardia syndrome (POTS). We report that POTS may also occur in adolescents and represents a mild, potentially treatable form of autonomic dysfunction that can be readily identified during head upright tilt table testing.
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Affiliation(s)
- B Karas
- Department of Medicine, Medical College of Ohio, Toledo, USA
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Abstract
Upright posture imposes a substantial gravitational stress on the body, for which we are able to compensate, in large part because of the autonomic nervous system. Alteration in autonomic function, therefore, may lead to orthostatic intolerance. On one extreme, patients with autonomic failure caused by degenerative loss of autonomic function are severely disabled by orthostatic hypotension and may faint whenever they stand up. Fortunately, such patients are relatively rare. On the other hand, disabling orthostatic intolerance can develop in otherwise normal young people. These patients can be severely impaired by symptoms of fatigue, tachycardia, and shortness of breath when they stand up. The actual incidence of this disorder is unknown, but these patients make up the largest group of patients referred to centers that specialize in autonomic disorders. We will review recent advances made in the understanding of this condition, potential pathophysiological mechanisms that contribute to orthostatic intolerance, therapeutic alternatives currently available for the management of these patients, and areas in which more research is needed.
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Affiliation(s)
- G Jacob
- Recanati Autonomic Dysfunction Center, Department of Internal Medicine C, Rambam Medical Center, Haifa, Israel
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Grubb BP, Kosinski DJ, Boehm K, Kip K. The postural orthostatic tachycardia syndrome: a neurocardiogenic variant identified during head-up tilt table testing. Pacing Clin Electrophysiol 1997; 20:2205-12. [PMID: 9309745 DOI: 10.1111/j.1540-8159.1997.tb04238.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Head upright tilt table testing has emerged as an accepted modality for identifying an individual's predisposition to episodes of autonomically mediated hypotension and bradycardia that are sufficiently profound so that transient loss of consciousness ensues (neurocardiogenic syncope). However it has also become apparent that less dramatic falls in blood pressure, while not sufficient to cause full syncope, may produce symptoms such as near syncope, vertigo, dizziness, and TIA-like episodes. We have identified a subgroup of individuals with a mild form of autonomic dysfunction with symptoms of postural tachycardia and lightheadedness, disabling fatigue, exercise intolerance, dizziness, and near syncope. During baseline tilt table testing these patients demonstrated a heart rate increase of > or = 30 beats/min (or a maximum heart rate of 120 beats/min) within the first 10 minutes upright (unassociated with profound hypotension), which reproduced their symptom complex. In addition these patients exhibit an exaggerated response to isoproterenol infusions. Similar observations have been made by others who have dubbed this entity the Postural Orthostatic Tachycardia Syndrome (POTS). We conclude that POTS represents a mild (and potentially treatable) from of autonomic dysfunction that can be readily diagnosed during head upright tilt table testing.
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Affiliation(s)
- B P Grubb
- Department of Medicine, Medical College of Ohio, Toledo 43699, USA
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Abstract
This article reviews the potential of a number of drug classes to produce or aggravate hypertension, with particular emphasis on older patients. Although little information is available regarding the hypertensive effects of mineralocorticoids in the elderly, glucocorticoids usually induce an increase in blood pressure (BP) that is dosage-dependent. Nonsteroidal anti-inflammatory drugs occasionally increase BP, but this effect is not usually clinically relevant. The alleged hypertensive potential of oral antihyperglycaemic agents has not yet been substantiated. In contrast, some antidepressants may be particularly dangerous in terms of their hypertensive complications. Although hypertension may be induced by monoamine oxidase inhibitors (MAOIs) given as monotherapy, severe hypertension is more likely to occur when MAOIs are combined with other sympathomimetic drugs. Several other drugs may also increase the risk of hypertension in elderly patients, but reliable data are lacking for most of these agents. Elderly people who are being treated with drugs that may increase BP should be closely monitored. This is particularly true for drugs that act on the CNS.
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Affiliation(s)
- P W de Leeuw
- Department of Medicine, University Hospital Maastricht, The Netherlands
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Affiliation(s)
- J Vernikos
- Life and Biomedical Sciences Applications, NASA Headquarters, Washington, DC 20546, USA
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Abstract
Orthostatic hypotension after even short space flights has affected a significant number of astronauts. Given the need for astronauts to function at a high level of efficiency during and after their return from space, the application of pharmacologic and other treatments is strongly indicated. This report addresses the clinical problem of orthostatic hypotension and its treatments to ascertain whether pharmacologic or physiologic treatment may be useful in the prevention of orthostatic hypotension associated with space flight. Treatment of orthostatic hypotension in patients now includes increasing intravascular volume with high sodium intake and mineralocorticoids, or increasing vascular resistance through the use of drugs to stimulate alpha or block beta vascular receptors. Earlier treatment used oral sympathomimetic ephedrine hydrochloride alone or with "head-up" bed rest. Then long-acting adrenocortical steroid desoxycorticosterone preparations with high-salt diets were used to expand volume. Fludrocortisone was shown to prevent the orthostatic drop in blood pressure. The combination of the sympathomimetic amine hydroxyamphetamine and a monoamine oxidase inhibitor tranylcypromine has been used, as has indomethacin alone. Davies et al. used mineralocorticoids at low doses concomitantly with alpha-agonists to increase vasoconstrictor action. Schirger et al used tranylcypromine and methylphenidate with or without a Jobst elastic leotard garment or the alpha-adrenergic agonist midodrine (which stimulates both arterial and venous systems without direct central nervous system or cardiac effects). Vernikos et al established that the combination of fludrocortisone, dextroamphetamine, and atropine exhibited a beneficial effect on orthostatic hypotension induced by 7-day 6 degrees head-down bed rest (a model used to simulate the weightlessness of space flight). Thus, there are numerous drugs that, in combination with mechanical techniques, including lower body negative pressure to elevate transmural pressure, could be studied to treat orthostatic hypotension after space flight.
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Affiliation(s)
- C M Lathers
- NASA/Johnson Space Center, Space Biomedical Research Institute, Houston, Texas
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Vernikos J, Convertino VA. Advantages and disadvantages of fludrocortisone or saline load in preventing post-spaceflight orthostatic hypotension. ACTA ASTRONAUTICA 1994; 33:259-266. [PMID: 11537971 DOI: 10.1016/0094-5765(94)90133-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The purpose of this study was to compare the effectiveness of saline load to fludrocortisone (florinef) as countermeasures for reduced plasma volume and orthostatic intolerance after spaceflight. Eleven males (ages 30-50 yr) underwent a 3-day ambulatory baseline period followed by 7 days of 6 degrees head-down bedrest, during which cardiopulmonary and arterial baroreflex sensitivity and plasma volume (PV) were determined. During pre-bedrest and 2.5 h after treatment on day 8, PV was also measured and subjects underwent a 15-min unsupported stand test. Treatments consisted of 8 salt tablets (1 g NaCl per tablet) and 960 ml of water in 5 subjects and 0.6 mg (0.2 mg x 3) over 24 h in the other 6 subjects. PV decreased by 12% on day 7 of bedrest. This was restored on day 8 by florinef but not by saline load. The effect of florinef on PV was paralleled by decreases in urine volume and the urinary sodium/potassium ratio. Reduced PV was associated with greater vascular resistance for the same drop in central venous pressure, suggesting less vasoconstriction reserve after bedrest. Carotid baroreflex control of heart rate was attenuated after 7 days of bedrest. Both baroreflex functions were restored by florinef but not saline load. Only 1 of 6 subjects showed syncopal symptoms in the florinef-treated group, whereas 4 of 5 subjects did so in the saline-load group. Acute florinef treatment appears to have distinct advantages as a protective measure for post-bedrest orthostatic intolerance, not only through its salt retaining, volume-expanding mineralcorticoid effect, but possibly through its actions on baroreflex and sympathetic functions.
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Lathers CM, Charles JB. Use of lower body negative pressure to counter symptoms of orthostatic intolerance in patients, bed rest subjects, and astronauts. J Clin Pharmacol 1993; 33:1071-85. [PMID: 8300890 DOI: 10.1002/j.1552-4604.1993.tb01944.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This report briefly discusses some aspects of autonomic cardiovascular dysfunction as related to changes in orthostatic function in patients, bed rest subjects, and astronauts. This relationship is described in normal individuals to provide the basis for discussion of parameters that may be altered in patients, bed rest subjects, and astronauts. The relationships between disease states, age, periods of weightlessness during space flight, and autonomic dysfunction, and their contribution to changes in orthostatic tolerance are presented. The physiologic effects of lower body negative pressure are illustrated by presenting data obtained in bed rest subjects and in astronauts. Finally, the usefulness of lower body negative pressure to counter symptoms of orthostatic intolerance in patients, bed rest subjects, and astronauts is discussed.
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Affiliation(s)
- C M Lathers
- NASA/JSC, Space Biomedical Research Institute, Houston, TX 77058
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Affiliation(s)
- A L Tonkin
- Department of Clinical Pharmacology, Flinders Medical Centre, Bedford Park, SA
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Bannister R. The diagnosis and treatment of autonomic failure. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1990; 30 Suppl:S19-23. [PMID: 2212487 DOI: 10.1016/0165-1838(90)90095-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- R Bannister
- National Hospital for Nervous Diseases, London, U.K
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Abstract
Many drugs have been used in treating patients with postural hypotension but for a large number the evidence of benefit is small and the potential for adverse effects, particularly supine hypertension, is great. Full clinical assessment is essential at the outset to define the nature and extent of pathophysiological disturbance of autonomic function. Many patients can be treated adequately by sleeping with the head of the bed elevated, and the use of fludrocortisone. Patients without evidence of central neurological deficit may benefit from additional treatment with drugs which alter beta-adrenoceptor tone. Patients who respond poorly to these measures should be admitted to hospital, and treatment with desmopressin initiated. Symptomatic postprandial hypotension should be identified early since the response to these measures alone is often poor, caffeine administered before eating, with abstinence for the rest of the day, may be very helpful.
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Affiliation(s)
- R A Ahmad
- Department of Cardiology, Dudley Road Hospital, Birmingham, England
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Unwin RJ, Mathias CJ, Peart WS, Frankel HL. Renal vascular responses to saralasin in conscious chemically denervated rabbits and patients with tetraplegia. CLINICAL AND EXPERIMENTAL HYPERTENSION. PART A, THEORY AND PRACTICE 1986; 8:919-39. [PMID: 2944679 DOI: 10.3109/10641968609044078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
To determine the relative contributions of direct angiotensin-II-like myotropism and sympathetic nerve stimulation to the partial agonist effect of saralasin, the renal vascular responses to i.v. saralasin (5, 10, 20 micrograms/kg/min) were assessed in normal conscious rabbits before and after sympatholytic treatment with guanethidine (24 mg/kg/day for 9 days) and in 6 chronic tetraplegic patients (0.5, 1, 5 micrograms/kg/min) before and after alpha-adrenoreceptor blockade with i.v. thymoxamine (1 mg/kg/h). In rabbits saralasin reduced effective renal plasma flow (ERPF) and glomerular filtration rate (GFR), and increased renal vascular resistance (RVR) without affecting mean arterial blood pressure (BP). Responses were similar in both groups, but recovery following saralasin was more prolonged after treatment with guanethidine. When 0.1 microgram/kg/min (one fiftieth of the smallest i.v. dose) was infused just proximal to the renal arteries in 4 conscious rabbits (chronically cannulated), renal perfusion fell and RVR increased. In tetraplegics saralasin produced a transient rise in BP and variable increase in RVR; neither response being altered by thymoxamine. These results suggest that saralasin-induced renal vasoconstriction is independent of central and peripheral sympathetic activation, and is probably due to an intrinsic angiotensin-II-like myotropic action.
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Perucca E, Richens A. Alterations of drug toxicity in neuropsychiatric disease states. ARCHIVES OF TOXICOLOGY. SUPPLEMENT. = ARCHIV FUR TOXIKOLOGIE. SUPPLEMENT 1984; 7:48-57. [PMID: 6596018 DOI: 10.1007/978-3-642-69132-4_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Potentially adverse alterations in drug response in patients with neuropsychiatric disease can be divided into two categories: those arising from the pathological state itself (e.g., enhanced responsiveness to phenylephrine in patients with chronic autonomic failure) and those arising from interactions with the pharmacological treatment used for such disease (e.g., reversal of the antihypertensive action of guanethidine by imipramine). Sound knowledge of the pharmacological profile of individual compounds and of the pathophysiology of the disease is essential if drug therapy is to be used safely and effectively in these patients.
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Abstract
A prototype electromechanical analogue of the sympathetic division of the baroreceptor reflex arc was used to maintain blood pressure automatically in two patients with neurogenic orthostatic hypotension. The device prevented significant and sustained reductions in mean blood pressure when the patients were tilted up to 85 degrees. Upon achieving the preset mean blood pressure, the device maintained this pressure with a standard error of less than 2 mm Hg. Similar results were obtained when the patients were walking. The device did not cause supine hypertension during the trials.
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Wilcox CS, Lewis PS, Sever PS, Peart WS. The actions of saralasin on the renal circulation of man and dog; evidence for a sympathetic neural component to vasoconstriction. Eur J Clin Invest 1981; 11:77-83. [PMID: 6785099 DOI: 10.1111/j.1365-2362.1981.tb02043.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The mechanism of renal vasoconstriction produced by saralasin and its dependence on the sympathetic nervous system was investigated in subjects with mild essential hypertension and in anaesthetized dogs. Fluid or saline was given to maximize agonist vasoconstrictor responses. The changes in renal haemodynamics produced by intravenously infused saralasin (dose 0.01-10 microgram kg-1 min-1) were assessed by clearance methods. In the patients, it induced a dose-related renal vasoconstriction which correlated with a rise in plasma noradrenaline levels. In dogs with innervated kidneys it also caused vasoconstriction. But in dogs with denervated kidneys it caused vasodilatation. Infusion at the highest dose directly into the renal artery of denervated kidneys induced only vasodilatation. We conclude that one component of the renal vasoconstriction that occurs with intravenous saralasin infusions is mediated by the renal nerves.
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Man in 't Veld AJ, Schalekamp MA. Pindolol acts as beta-adrenoceptor agonist in orthostatic hypotension: therapeutic implications. BMJ : BRITISH MEDICAL JOURNAL 1981; 282:929-31. [PMID: 6781656 PMCID: PMC1504785 DOI: 10.1136/bmj.282.6268.929] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Three bedridden patients with severe orthostatic hypotension due to chronic autonomic failure were treated with pindolol (15 mg/day), a beta-adrenoceptor antagonist with partial agonist activity. While taking this drug the patients were free of orthostatic symptoms: they could walk, and standing blood pressure was maintained above 90/50 mm Hg. Supine heart rate rose during treatment by 12-21 beats/minute, and stroke volume and cardiac output by 12-24 ml and 1.5-3.1 l/min respectively. Supine blood pressure rose by 21-68 mm Hg systolic and 14-49 mm Hg diastolic. Pindolol 15 mg/day was therapeutically effective in these three patients with severe orthostatic hypotension due to chronic autonomic failure. Further studies in a larger series of patients are needed to confirm this result.
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Parkinsonism, system degenerations and autonomic failure. Mov Disord 1981. [DOI: 10.1016/b978-0-407-02295-9.50016-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] Open
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Davies IB, Bannister R, Hensby C, Sever PS. The pressor actions of noradrenaline and angiotension II in chronic autonomic failure treated with indomethacin. Br J Clin Pharmacol 1980; 10:223-9. [PMID: 7437238 PMCID: PMC1430064 DOI: 10.1111/j.1365-2125.1980.tb01748.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
1 Indomethacin treatment of postural hypotension in four patients with chronic autonomic failure increased their pressor supersensitivity to intravenous noradrenaline without causing fluid retention. 2 All patients were supersensitive to angiotensin II in spite of normal levels of plasma renin activity in the supine position and therefore (by inference) of angiotensin II. This suggests that in autonomic failure, the degree of angiotensin receptor occupancy by endogenous angiotensin II is not important in determining pressor sensitivity to exogenous angiotensin II. Indomethacin increased the pressor supersensitivity to angiotensin II in all patients. 3 Indomethacin treatment decreased supine plasma renin activity to 50% of the level present before indomethacin treatment. 4 Indomethacin increased the lying but not the standing blood pressure. The failure to raise the standing pressure may be the result of the additional postural stress overcoming any vasoconstriction resulting from the increased sensitivity of vascular receptors to noradrenaline. The decrease in plasma renin activity could also contribute to the failure of indomethacin to prevent a fall in blood pressure on standing. 5 In our patients the excretion of the main urinary metabolite (PGFM) of prostaglandin F2 alpha was higher than recorded previously in normal controls. During treatment with indomethacin, plasma indomethacin levels were in the range at which inhibition of prostaglandin synthesis occurs and the excretion of PGFM was decreased. 6 Indomethacin was not effective in the treatment of postural hypotension in these patients with autonomic failure.
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Davies IB, Bannister R, Sever PS. Indomethacin treatment of postural hypotension in autonomic failure. BRITISH MEDICAL JOURNAL 1980; 280:181. [PMID: 7357311 PMCID: PMC1600307 DOI: 10.1136/bmj.280.6208.181-a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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