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Williams EL, Hockin BCD, Heeney ND, Elabd K, Chong H, Blaber AP, Robinovitch SN, Parsons IT, Claydon VE. Exaggerated postural sway improves orthostatic cardiovascular and cerebrovascular control. Front Cardiovasc Med 2023; 10:1040036. [PMID: 36873416 PMCID: PMC9978805 DOI: 10.3389/fcvm.2023.1040036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 01/23/2023] [Indexed: 02/18/2023] Open
Abstract
Introduction Healthy individuals with poor cardiovascular control, but who do not experience syncope (fainting), adopt an innate strategy of increased leg movement in the form of postural sway that is thought to counter orthostatic (gravitational) stress on the cardiovascular system. However, the direct effect of sway on cardiovascular hemodynamics and cerebral perfusion is unknown. If sway produces meaningful cardiovascular responses, it could be exploited clinically to prevent an imminent faint. Methods Twenty healthy adults were instrumented with cardiovascular (finger plethysmography, echocardiography, electrocardiogram) and cerebrovascular (transcranial Doppler) monitoring. Following supine rest, participants performed a baseline stand (BL) on a force platform, followed by three trials of exaggerated sway (anterior-posterior, AP; mediolateral, ML; square, SQ) in a randomized order. Results All exaggerated postural sway conditions improved systolic arterial pressure (SAP, p = 0.001) responses, while blunting orthostatic reductions in stroke volume (SV, p < 0.01) and cerebral blood flow (CBFv, p < 0.05) compared to BL. Markers of sympathetic activation (power of low-frequency oscillations in SAP, p < 0.001) and maximum transvalvular flow velocity (p < 0.001) were reduced during exaggerated sway conditions. Responses were dose-dependent, with improvements in SAP (p < 0.001), SV (p < 0.001) and CBFv (p = 0.009) all positively correlated with total sway path length. Coherence between postural movements and SAP (p < 0.001), SV (p < 0.001) and CBFv (p = 0.003) also improved during exaggerated sway. Discussion Exaggerated sway improves cardiovascular and cerebrovascular control and may supplement cardiovascular reflex responses to orthostatic stress. This movement provides a simple means to boost orthostatic cardiovascular control for individuals with syncope, or those with occupations that require prolonged motionless standing.
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Affiliation(s)
- Erin L Williams
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Brooke C D Hockin
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Natalie D Heeney
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Karam Elabd
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Helen Chong
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Andrew P Blaber
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Stephen N Robinovitch
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Iain T Parsons
- Research and Clinical Innovation, Royal Centre for Defence Medicine, Birmingham, United Kingdom.,School of Cardiovascular Medicine and Sciences, King's College London, London, United Kingdom
| | - Victoria E Claydon
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
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Williams EL, Khan FM, Claydon VE. Counter pressure maneuvers for syncope prevention: A semi-systematic review and meta-analysis. Front Cardiovasc Med 2022; 9:1016420. [PMID: 36312294 PMCID: PMC9606335 DOI: 10.3389/fcvm.2022.1016420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 09/20/2022] [Indexed: 11/24/2022] Open
Abstract
Physical counter pressure maneuvers (CPM) are movements that are recommended to delay or prevent syncope (fainting) by recruiting the skeletal muscle pump to augment cardiovascular control. However, these recommendations are largely based on theoretical benefit, with limited data evaluating the efficacy of CPM to prevent syncope in the real-world setting. We conducted a semi-systematic literature review and meta-analysis to assess CPM efficacy, identify literature gaps, and highlight future research needs. Articles were identified through a literature search (PubMed, April 2022) of peer-reviewed publications evaluating the use of counter pressure or other lower body maneuvers to prevent syncope. Two team members independently screened records for inclusion and extracted data. From 476 unique records identified by the search, 45 met inclusion criteria. Articles considered various syncopal conditions (vasovagal = 12, orthostatic hypotension = 8, postural orthostatic tachycardia syndrome = 1, familial dysautonomia = 2, spinal cord injury = 1, blood donation = 10, healthy controls = 11). Maneuvers assessed included hand gripping, leg fidgeting, stepping, tiptoeing, marching, calf raises, postural sway, tensing (upper, lower, whole body), leg crossing, squatting, “crash” position, and bending foreword. CPM were assessed in laboratory-based studies (N = 28), the community setting (N = 4), both laboratory and community settings (N = 3), and during blood donation (N = 10). CPM improved standing systolic blood pressure (+ 14.8 ± 0.6 mmHg, p < 0.001) and heart rate (+ 1.4 ± 0.5 bpm, p = 0.006), however, responses of total peripheral resistance, stroke volume, or cerebral blood flow were not widely documented. Most patients experienced symptom improvement following CPM use (laboratory: 60 ± 4%, community: 72 ± 9%). The most prominent barrier to employing CPM in daily living was the inability to recognize an impending faint. Patterns of postural sway may also recruit the skeletal muscle pump to enhance cardiovascular control, and its potential as a discrete, proactive CPM needs further evaluation. Physical CPM were successful in improving syncopal symptoms and producing cardiovascular responses that may bolster against syncope; however, practical limitations may restrict applicability for use in daily living.
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Dani M, Taraborrelli P, Panagopoulos D, Dirksen A, Torocastro M, Sutton R, Lim PB. New horizons in the ageing autonomic nervous system: orthostatic hypotension and supine hypertension. Age Ageing 2022; 51:6653480. [PMID: 35930723 PMCID: PMC9724614 DOI: 10.1093/ageing/afac150] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Indexed: 01/25/2023] Open
Abstract
Blood pressure regulation is an automatic, moment-by-moment buffering of the blood pressure in response to physiological changes such as orthostasis, exercise and haemorrhage. This finely orchestrated reflex is called the baroreflex. It is a regulated arc of afferent, central and efferent arms. Multiple physiological changes occur with ageing that can disrupt this reflex, making blood pressure regulation less effective. In addition, multiple changes can occur with ageing-related diseases such as neurodegeneration, atherosclerosis, deconditioning and polypharmacy. These changes commonly result in orthostatic hypotension, hypertension or both, and are consistently associated with multiple adverse outcomes. In this article, we discuss the healthy baroreflex, and physiological and pathophysiological reasons for impaired baroreflex function in older people. We discuss why the common clinical manifestations of orthostatic hypotension and concomitant supine hypertension occur, and strategies for balancing these conflicting priorities. Finally, we discuss strategies for treating them, outlining our practice alongside consensus and expert guidance.
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Affiliation(s)
- Melanie Dani
- Address correspondence to: Melanie Dani, Imperial Syncope Unit, Hammersmith Hospital, London W12 0HS, UK.
| | | | | | - Andreas Dirksen
- Imperial Syncope Unit, Imperial College Healthcare NHS Trust, London W12 0HS, UK
| | - Miriam Torocastro
- Imperial Syncope Unit, Imperial College Healthcare NHS Trust, London W12 0HS, UK
| | - Richard Sutton
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Phang Boon Lim
- Imperial Syncope Unit, Imperial College Healthcare NHS Trust, London W12 0HS, UK
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4
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Kowalsky JM. Predicting COVID-19 and seasonal influenza vaccine uptake: The impact of fear and vasovagal symptoms. Appl Psychol Health Well Being 2022; 15:293-314. [PMID: 35705510 PMCID: PMC9349497 DOI: 10.1111/aphw.12380] [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: 12/29/2021] [Accepted: 05/29/2022] [Indexed: 11/29/2022]
Abstract
Vaccines are vital to protecting health. However, fear and experiencing vasovagal symptoms (e.g., dizziness) are deterrents to medical procedures. Thus, study aims were to test (1) if vaccine relevant fears predict vasovagal symptoms during or following seasonal influenza vaccination and (2) if vaccine relevant fears and vasovagal symptoms predict seasonal influenza and COVID-19 vaccine uptake. Using a prospective design, 1077 participants recruited online completed surveys during Oct 2019 assessing vaccine relevant fears, and May-June 2020 assessing 2019-2020 seasonal influenza vaccine uptake, ratings of vasovagal symptoms, and seasonal influenza and COVID-19 vaccination intention. A behavioral follow up assessing 2020-2021 seasonal influenza and COVID-19 vaccine uptake took place June-July 2021. Heightened vaccine relevant fears predicted reduced 2019-2020 seasonal influenza vaccine uptake and greater vasovagal symptoms among those who did receive a seasonal influenza vaccine. Serial mediation analyses identified significant indirect effects with greater vaccine relevant fears reducing 2020-2021 seasonal influenza vaccine uptake through intention and reducing COVID-19 vaccine uptake through vasovagal symptoms and intention. Intervention research to reduce fear and prevent vasovagal symptoms to support vaccine uptake is warranted.
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Erste Hilfe. Notf Rett Med 2021. [DOI: 10.1007/s10049-021-00886-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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6
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Zideman DA, Singletary EM, Borra V, Cassan P, Cimpoesu CD, De Buck E, Djärv T, Handley AJ, Klaassen B, Meyran D, Oliver E, Poole K. European Resuscitation Council Guidelines 2021: First aid. Resuscitation 2021; 161:270-290. [PMID: 33773828 DOI: 10.1016/j.resuscitation.2021.02.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The European Resuscitation Council has produced these first aid guidelines, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics include the first aid management of emergency medicine and trauma. For medical emergencies the following content is covered: recovery position, optimal positioning for shock, bronchodilator administration for asthma, recognition of stroke, early aspirin for chest pain, second dose of adrenaline for anaphylaxis, management of hypoglycaemia, oral rehydration solutions for treating exertion-related dehydration, management of heat stroke by cooling, supplemental oxygen in acute stroke, and presyncope. For trauma related emergencies the following topics are covered: control of life-threatening bleeding, management of open chest wounds, cervical spine motion restriction and stabilisation, recognition of concussion, cooling of thermal burns, dental avulsion, compression wrap for closed extremity joint injuries, straightening an angulated fracture, and eye injury from chemical exposure.
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Affiliation(s)
| | | | - Vere Borra
- Centre for Evidence-based Practice, Belgian Red Cross, Mechelen, Belgium; Cochrane First Aid, Mechelen, Belgium
| | - Pascal Cassan
- International Federation of Red Cross and Red Crescent, France
| | - Carmen D Cimpoesu
- University of Medicine and Pharmacy "Grigore T. Popa", Iasi, Emergency Department and Prehospital EMS SMURD Iasi Emergency County Hospital "Sf. Spiridon" Iasi, Romania
| | - Emmy De Buck
- Centre for Evidence-based Practice, Belgian Red Cross, Mechelen, Belgium; Cochrane First Aid, Mechelen, Belgium; Department of Public Health and Primary Care, Faculty of Medicine, KU Leuven, Leuven, Belgium
| | - Therese Djärv
- Department of Medicine Solna, Karolinska Institute and Division of Acute and Reparative Medicine, Karolinska University Hospital, Sweden
| | | | - Barry Klaassen
- Emergency Medicine, Ninewells Hospital and Medical School Dundee, UK; British Red Cross, UK
| | - Daniel Meyran
- French Red Cross, Bataillon de Marins Pompiers de Marseille, France
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7
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Mitro P, Muller E, Lazurova Z. Hemodynamic differences in isometric counter-pressure maneuvers and their efficacy in vasovagal syncope. INTERNATIONAL JOURNAL OF ARRHYTHMIA 2019. [DOI: 10.1186/s42444-019-0003-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Isometric counter-pressure maneuvers (ICM) were proposed as first-line treatment in patients with vasovagal syncope (VVS). The aim was to study hemodynamic mechanisms and effectiveness of ICM in prevention of head-up tilt (HUT)-induced and spontaneous VVS.
Methods
In 38 patients with VVS (9 men, 28 women, mean age 35.82 ± 15.2 years), following ICM were performed—squatting (SQ), leg crossing with muscle tensing (LCMT), whole-body tensing (WBT), heel raises (HeR), toe extension (TE), and unilateral handgrip (HG). Hemodynamic parameters were recorded during ICM using photopletysmographic principle: blood pressure, heart rate, cardiac output, stroke volume, and total peripheral resistance. Clinical efficacy of ICM was assessed during HUT-induced presyncope. The recurrence of syncope and quality of life were also evaluated during 26 ± 7 month follow-up period.
Results
All maneuvers increased mean arterial pressure. The hemodynamic background of ICM was not uniform. In most ICM (LCMT, WBT, HeR, and TE), an increase in CO due to simultaneous increase in HR and SV was observed. In SQ, the underlying mechanism was augmentation of stroke volume by increased venous return. In unilateral HG, a rise in peripheral resistance was the principal mechanism. ICM were able to prevent syncope in 47% of patients during HUT-induced presyncope and in 71% of patients during spontaneous presyncope. Quality of life improved in all patients.
Conclusions
ICM increase blood pressure by variable hemodynamic mechanisms. ICM effectively counteract the HUT-induced and spontaneous vasovagal syncope and improve quality of life.
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8
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Finucane C, van Wijnen VK, Fan CW, Soraghan C, Byrne L, Westerhof BE, Freeman R, Fedorowski A, Harms MPM, Wieling W, Kenny R. A practical guide to active stand testing and analysis using continuous beat-to-beat non-invasive blood pressure monitoring. Clin Auton Res 2019; 29:427-441. [PMID: 31076939 DOI: 10.1007/s10286-019-00606-y] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 04/02/2019] [Indexed: 12/19/2022]
Abstract
PURPOSE The average adult stands approximately 50-60 times per day. Cardiovascular responses evoked during the first 3 min of active standing provide a simple means to clinically assess short-term neural and cardiovascular function across the lifespan. Clinically, this response is used to identify the haemodynamic correlates of patient symptoms and attributable causes of (pre-)syncope, and to detect autonomic dysfunction, variants of orthostatic hypotension, postural orthostatic tachycardia syndrome and orthostatic hypertension. METHODS This paper provides a set of experience/expertise-based recommendations detailing current state-of-the-art measurement and analysis approaches for the active stand test, focusing on beat-to-beat BP technologies. This information is targeted at those interested in performing and interpreting the active stand test to current international standards. RESULTS This paper presents a practical step-by-step guide on (1) how to perform active stand measurements using beat-to-beat continuous blood pressure measurement technologies, (2) how to conduct an analysis of the active stand response and (3) how to identify the spectrum of abnormal blood pressure and heart rate responses which are of clinical interest. CONCLUSION Impairments in neurocardiovascular control are an attributable cause of falls and syncope across the lifespan. The simple active stand test provides the clinician with a powerful tool for assessing individuals at risk of such common disorders. However, its simplicity belies the complexity of its interpretation. Care must therefore be taken in administering and interpreting the test in order to maximise its clinical benefit and minimise its misinterpretation.
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Affiliation(s)
- Ciarán Finucane
- Department of Medical Physics and Bioengineering, Mercer's Institute for Successful Ageing, St. James's Hospital, Dublin 8, Ireland.
- Mercer's Institute for Successful Ageing, St. James's Hospital, Dublin 8, Ireland.
- Department of Medical Gerontology, Trinity College Dublin, The Irish Longitudinal Study on Ageing (TILDA), Dublin, Ireland.
| | - V K van Wijnen
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - C W Fan
- Department of Gerontology, Mater Misericordiae University Hospital, Dublin, Ireland
| | - C Soraghan
- Department of Medical Physics and Bioengineering, Mercer's Institute for Successful Ageing, St. James's Hospital, Dublin 8, Ireland
- Mercer's Institute for Successful Ageing, St. James's Hospital, Dublin 8, Ireland
| | - L Byrne
- Mercer's Institute for Successful Ageing, St. James's Hospital, Dublin 8, Ireland
| | - B E Westerhof
- Amsterdam UMC, Vrije Universiteit Amsterdam, Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
- Amsterdam UMC, University of Amsterdam, Medical Biology, Section of Systems Physiology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - R Freeman
- Neurology Department, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, USA
| | - A Fedorowski
- Department of Clinical Sciences, Clinical Research Center, Lund University, Malmö, Sweden
- Department of Cardiology, Skåne University Hospital, Malmö, Sweden
| | - M P M Harms
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - W Wieling
- Department of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - R Kenny
- Mercer's Institute for Successful Ageing, St. James's Hospital, Dublin 8, Ireland
- Department of Medical Gerontology, Trinity College Dublin, The Irish Longitudinal Study on Ageing (TILDA), Dublin, Ireland
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9
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Jensen JL, Ohshimo S, Cassan P, Meyran D, Greene J, Ng KC, Singletary E, Zideman D. Immediate Interventions for Presyncope of Vasovagal or Orthostatic Origin: A Systematic Review. PREHOSP EMERG CARE 2019; 24:64-76. [DOI: 10.1080/10903127.2019.1605431] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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10
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Mennitto S, Harrison J, Ritz T, Robillard P, France CR, Ditto B. Respiration and applied tension strategies to reduce vasovagal reactions to blood donation: A randomized controlled trial. Transfusion 2018; 59:566-573. [DOI: 10.1111/trf.15046] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 09/26/2018] [Accepted: 09/26/2018] [Indexed: 11/29/2022]
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Effects of respiratory and applied muscle tensing interventions on responses to a simulated blood draw among individuals with high needle fear. J Behav Med 2018; 41:771-783. [PMID: 29679183 DOI: 10.1007/s10865-018-9925-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 04/11/2018] [Indexed: 10/17/2022]
Abstract
Fear of blood and needles increases risk for presyncopal symptoms. Applied muscle tension can prevent or attenuate presyncopal symptoms; however, it is not universally effective. This study examined the effects of applied muscle tension, a respiratory intervention, and a no treatment control condition, on presyncopal symptoms and cerebral oxygenation, during a simulated blood draw with individuals highly fearful of needles. Participants (n = 95) completed questionnaires, physiological monitoring, and two trials of a simulated blood draw with recovery. Presyncopal symptoms decreased across trials; however, no group differences emerged. Applied muscle tension was associated with greater cerebral oxygenation during trial two, and greater end-tidal carbon dioxide during both trials. The respiratory intervention did not differ from the no treatment control. Applied muscle tension is an intervention that can increase cerebral oxygenation and end-tidal carbon dioxide. While the respiratory intervention is promising within therapeutic settings, it was not efficacious after a brief audio training.
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12
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Nelson AL, Massoudi N. New developments in intrauterine device use: focus on the US. Open Access J Contracept 2016; 7:127-141. [PMID: 29386944 PMCID: PMC5683151 DOI: 10.2147/oajc.s85755] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Many more women in the US today rely upon intrauterine devices (IUDs) than in the past. This increased utilization may have substantially contributed to the decline in the percentage of unintended pregnancies in the US. Evidence-based practices have increased the number of women who are medically eligible for IUDs and have enabled more rapid access to the methods. Many women enjoy freedom to use IUDs without cost, but for many the impact of the Affordable Care Act has yet to be realized. Currently, there are three hormonal IUDs and one copper IUD available in the US. Each IUD is extremely effective, convenient, and safe. The newer IUDs have been tested in populations not usually included in clinical trials and provide reassuring answers to older concerns about IUD use in these women, including information about expulsion, infection, and discontinuation. On the other hand, larger surveillance studies have provided new estimates about the risks of complications such as perforation, especially in postpartum and breastfeeding women. This article summarizes significant features of each IUD and provides a summary of the differences to aid clinicians in the US and other countries in advising women about IUD choices.
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Affiliation(s)
- Anita L Nelson
- Department of Obstetrics and Gynecology, Los Angeles BioMedical Research Institute at Harbor-UCLA Medical Center, David Geffen School of Medicine at UCLA, Torrance, CA, USA
| | - Natasha Massoudi
- American University of the Caribbean School of Medicine, Cupecoy, Sint Maarten
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13
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Skoog J, Zachrisson H, Länne T, Lindenberger M. Slower Lower Limb Blood Pooling Increases Orthostatic Tolerance in Women with Vasovagal Syncope. Front Physiol 2016; 7:232. [PMID: 27378941 PMCID: PMC4906053 DOI: 10.3389/fphys.2016.00232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 05/30/2016] [Indexed: 11/28/2022] Open
Abstract
Background and Aim: Slower lower limb blood pooling and associated blunted sympathetic activation has been detected in healthy women prone to orthostatic syncope. Whether these findings are true also for patients with vasovagal syncope (VVS) is unknown. The aim was to investigate initial blood pooling time (poolingtime, time to 50% of total blood pooling) together with hemodynamic responses and orthostatic tolerance during lower body negative pressure (LBNP) in VVS and healthy controls. Methods and Results: Fourteen VVS women (25.7 ± 1.3 years) and 15 healthy women (22.8 ± 0.8 years) were subjected to single-step and graded LBNP to pre-syncope. Lower limb blood pooling (ml · 100 ml−1), poolingtime (s), hemodynamic responses and LBNP-tolerance were evaluated. LBNP induced comparable lower limb blood pooling in both groups (controls, 3.1 ± 0.3; VVS, 2.9 ± 0.3 ml · 100 ml−1, P = 0.70). In controls, shorter poolingtime correlated to higher LBNP-tolerance (r = –0.550, P < 0.05) as well as better maintained stroke volume (r = –0.698, P < 0.01) and cardiac output (r = –0.563, P < 0.05). In contrast, shorter poolingtime correlated to lower LBNP-tolerance in VVS (r = 0.821, P < 0.001) and larger decline in stroke volume (r = 0.611, P < 0.05). Furthermore, in controls, shorter poolingtime correlated to baroreflex-mediated hemodynamic changes during LBNP, e.g., increased vasoconstriction (P < 0.001). In VVS, poolingtime was not correlated with LBNP-induced baroreceptor unloading, but rather highly correlated to resting calf blood flow (P < 0.001). Conclusions: Shorter poolingtime seems to elicit greater sympathetic activation with a concomitant higher orthostatic tolerance in healthy women. The contrasting findings in VVS indicate a deteriorated vascular sympathetic control suggesting well-defined differences already in the initial responses during orthostatic stress.
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Affiliation(s)
- Johan Skoog
- Department of Medical and Health Sciences, Linköping UniversityLinköping, Sweden
- *Correspondence: Johan Skoog
| | - Helene Zachrisson
- Department of Clinical Physiology and Department of Medical and Health Sciences, Linköping UniversityLinköping, Sweden
| | - Toste Länne
- Department of Medical and Health Sciences, Linköping UniversityLinköping, Sweden
| | - Marcus Lindenberger
- Department of Cardiology and Department of Medical and Health Sciences, Linköping UniversityLinköping, Sweden
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14
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Wieling W, van Dijk N, Thijs RD, de Lange FJ, Krediet CTP, Halliwill JR. Physical countermeasures to increase orthostatic tolerance. J Intern Med 2015; 277:69-82. [PMID: 24697914 DOI: 10.1111/joim.12249] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- W Wieling
- Department of Internal Medicine, Academic Medical Centre University of Amsterdam, Amsterdam, the Netherlands
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Lacewell AN, Buck TM, Romero SA, Halliwill JR. Postexercise syncope: Wingate syncope test and effective countermeasure. Exp Physiol 2013; 99:172-86. [PMID: 24078670 DOI: 10.1113/expphysiol.2013.075333] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Altered systemic haemodynamics following exercise can compromise cerebral perfusion and result in syncope. As the Wingate anaerobic test often induces presyncope, we hypothesized that a modified Wingate test could form the basis of a novel model for the study of postexercise syncope and a test bed for potential countermeasures. Along these lines, breathing through an impedance threshold device has been shown to increase tolerance to hypovolaemia, and could prove beneficial in the setting of postexercise syncope. Therefore, we hypothesized that a modified Wingate test followed by head-up tilt would produce postexercise syncope, and that breathing through an impedance threshold device (countermeasure) would prevent postexercise syncope in healthy individuals. Nineteen recreationally active men and women underwent a 60 deg head-up tilt during recovery from the Wingate test while arterial pressure, heart rate, end-tidal CO2 and cerebral tissue oxygenation were measured on a control day and a countermeasure day. The duration of tolerable tilt was increased by a median time of 3 min 48 s with countermeasure in comparison to the control (P < 0.05), and completion of the tilt test increased from 42 to 67% with the countermeasure. During the tilt, mean arterial pressure was greater (108.0 ± 4.1 versus 100.4 ± 2.4 mmHg; P < 0.05) with the countermeasure in comparison to the control. These data suggest that the Wingate syncope test produces a high incidence of presyncope, which is sensitive to countermeasures such as inspiratory impedance.
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Affiliation(s)
- Alisha N Lacewell
- J. R. Halliwill: 122 Esslinger Hall, 1240 University of Oregon, Eugene, OR 97403-1240, USA.
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16
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Nådland IH, Wesche J, Sheriff DD, Toska K. Does venous insufficiency impair the exercise-induced rise in arterial leg blood flow? Phlebology 2011; 26:326-31. [DOI: 10.1258/phleb.2011.010092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Objectives It has been shown that the leg muscle pump increases the immediate rise in arterial leg blood flow during upright exercise in healthy subjects. The present study is the first to investigate the muscle pump effect in exercise hyperaemia in patients with venous insufficiency, who should be lacking an optimally functioning muscle pump. Methods Any muscle pump effect is more pronounced in an upright position because of gravitation. The exercise-induced rise in femoral artery flow (FF) (ultrasound Doppler) was thus compared in the supine and 30° head-up tilted position in 10 patients. Results Neither the transient nor the steady-state rise in FF showed any difference between positions. This is in contrast to the previous findings in healthy subjects, where the transient rise in FF was larger in the tilted position. Conclusion The muscle pump effect in exercise hyperaemia seems to be reduced or lacking in these patients.
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Affiliation(s)
- I H Nådland
- Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, PO Box 1103 Blindern, NO-0317, Oslo
- Department of Vascular and Thoracic Surgery, Akershus University Hospital, 1478 Lørenskog
| | - J Wesche
- Department of Vascular and Thoracic Surgery, Akershus University Hospital, 1478 Lørenskog
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - D D Sheriff
- Department of Integrative Physiology, The University of Iowa, Iowa City, IA, USA
| | - K Toska
- Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, PO Box 1103 Blindern, NO-0317, Oslo
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Nådland I, Wesche J, Sheriff D, Toska K. Does the Great Saphenous Vein Stripping Improve Arterial Leg Blood Flow During Exercise? Eur J Vasc Endovasc Surg 2011; 41:697-703. [DOI: 10.1016/j.ejvs.2011.01.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Accepted: 01/13/2011] [Indexed: 11/17/2022]
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O'Dwyer C, Bennett K, Langan Y, Fan CW, Kenny RA. Amnesia for loss of consciousness is common in vasovagal syncope. Europace 2011; 13:1040-5. [DOI: 10.1093/europace/eur069] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Kowalsky JM, France JL, Wissel ME, France CR. Effect of applied muscle tension on cerebral oxygenation in female blood donors. Transfusion 2011; 51:1802-8. [DOI: 10.1111/j.1537-2995.2011.03075.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Sheriff DD, Nådland IH, Toska K. Retrograde arterial leg blood flow during tilt-back from a head-up posture: importance of capacitive flows when arterial pressure changes. J Appl Physiol (1985) 2010; 108:533-7. [DOI: 10.1152/japplphysiol.01184.2009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The windkessel function of the arterial system converts the intermittent action of the heart into more continuous microcirculatory blood flow during diastole via the return of elastic energy stored in the walls of the arteries during systole. Might the same phenomenon occur regionally within the arterial system during tilting owing to regional differences in local arterial pressure imposed by gravity? We sought to test the hypothesis that during tilt-back from a head-up posture, the return of stored elastic energy in leg arteries would work to slow, or perhaps transiently reverse, the flow of blood in the femoral artery. Femoral artery blood flow and arterial pressure were recorded during tilt back from a 30° head-up posture to supine (∼0.5 G) in young, healthy subjects ( n = 7 males and 3 females) before and during clonidine infusion. During control (no drug) conditions femoral artery blood flow ceased for an entire heart beat during tilt-back. During clonidine infusion femoral artery blood flow reversed for at least one entire heart beat during tilt-back, i.e., blood flow in the retrograde direction in the femoral artery from the leg into the abdomen. Thus substantial capacitive effects of tilting on leg blood flow occur in humans during mild changes in posture.
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Affiliation(s)
- Don D. Sheriff
- Department of Integrative Physiology, The University of Iowa, Iowa City, Iowa; and
| | - Inger Helene Nådland
- The Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Karin Toska
- The Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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22
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Sheriff DD, Nådland IH, Toska K. Role of sympathetic responses on the hemodynamic consequences of rapid changes in posture in humans. J Appl Physiol (1985) 2010; 108:523-32. [PMID: 20056846 DOI: 10.1152/japplphysiol.01185.2009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Tolerance to +G(z) gravitational stress is reduced when +G(z) stress is preceded by exposure to hypogravity (fractional, 0, or negative G(z)). For example, there is an exaggerated fall in eye-level arterial pressure (ELAP) early on during +G(z) stress (head-up tilt; HUT) when this stress is immediately preceded by -G(z) stress (head-down tilt; HDT), termed the "push-pull effect." The aim of the present study was to test the hypothesis that sympathetic responses contribute to the push-pull effect. Young, healthy subjects (n = 7 males and 3 females) were subjected to 30 s of 30 degrees HUT from a horizontal position and to 30 s of 30 degrees HUT when HUT was immediately preceded by 20 s of -15 degrees HDT. Four bouts of HDT-HUT were alternated between five bouts of HUT in a counterbalanced design, and 1 min was allowed for recovery between tilts. This protocol was repeated during clonidine administration (2.5 microg/kg bolus over 30 min and then continuously at 0.36 microg x kg(-1) x h(-1)). Clonidine blunted the vasomotor responses to tilting, and this led to exaggerated changes in arterial pressure. Clonidine exerted little specific influence on the push-pull effect. Thus sympathetic responses appear neither to contribute to, nor protect against, the push-pull effect for the rate and duration of tilting imposed in the present study.
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Affiliation(s)
- Don D Sheriff
- Department of Integrative Physiology, The University of Iowa, Iowa City, IA 52245, USA
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Nådland IH, Walløe L, Toska K. Effect of the leg muscle pump on the rise in muscle perfusion during muscle work in humans. Eur J Appl Physiol 2009; 105:829-41. [PMID: 19125282 DOI: 10.1007/s00421-008-0965-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2008] [Indexed: 10/21/2022]
Abstract
The transient and steady-state effects of the calf muscle pump on the rise in muscle perfusion during rhythmic plantarflexions were investigated in 20 volunteers. Because a large hydrostatic column would increase the effect of a muscle pump, exercise in the supine and head-up tilted positions was compared. Within approximately 15 s of the start of muscle work, femoral artery flow (ultrasound Doppler) rose 0.37 L/min above rest in the supine and 0.5 L/min above rest in the tilted position. The latter is a significantly larger rise (P < 0.05). After 80 s of muscle work, femoral flow was stable at 0.38 and 0.39 L/min above rest in the supine and tilted positions, respectively. We conclude that the muscle pump contributes to muscle perfusion during the initial phase of muscle work, but that metabolic vasodilation is a more important determinant of muscle perfusion during steady-state muscle work.
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Affiliation(s)
- Inger Helene Nådland
- Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
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Groothuis JT, Poelkens F, Wouters CW, Kooijman M, Hopman MTE. Leg intravenous pressure during head-up tilt. J Appl Physiol (1985) 2008; 105:811-5. [PMID: 18635882 DOI: 10.1152/japplphysiol.90304.2008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Leg vascular resistance is calculated as the arterial-venous pressure gradient divided by blood flow. During orthostatic challenges it is assumed that the hydrostatic pressure contributes equally to leg arterial, as well as to leg venous pressure. Because of venous valves, one may question whether, during orthostatic challenges, a continuous hydrostatic column is formed and if leg venous pressure is equal to the hydrostatic pressure. The purpose of this study was, therefore, to measure intravenous pressure in the great saphenous vein of 12 healthy individuals during 30 degrees and 70 degrees head-up tilt and compare this with the calculated hydrostatic pressure. The height difference between the heart and the right medial malleolus level represented the hydrostatic column. The results demonstrate that there were no differences between the measured intravenous pressure and the calculated hydrostatic pressure during 30 degrees (47.2 +/- 1.0 and 46.9 +/- 1.5 mmHg, respectively) and 70 degrees head-up tilt (83.9 +/- 0.9 and 85.1 +/- 1.2 mmHg, respectively). Steady-state levels of intravenous pressure were reached after 95 +/- 12 s during 30 degrees and 161 +/- 15 s during 70 degrees head-up tilt. In conclusion, the measured leg venous pressure is similar to the calculated hydrostatic pressure during orthostatic challenges. Therefore, the assumption that hydrostatic pressure contributes equally to leg arterial as well as to leg venous pressure during orthostatic challenges can be made.
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Affiliation(s)
- Jan T Groothuis
- Radboud Univ. Nijmegen Medical Centre, Dept. of Physiology, Geert Grooteplein-noord 21, 6525 EZ Nijmegen, The Netherlands
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Which physiological mechanism is responsible for the increase in blood pressure during leg crossing? J Hypertens 2008; 26:433-7. [PMID: 18300852 DOI: 10.1097/hjh.0b013e3282f35276] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To determine which physiological mechanism is responsible for the blood pressure increase during leg crossing at knee-level in the sitting position. METHODS Finger blood pressure was measured with the Finometer in 102 participants (47 men) before and during leg crossing: 24 treated hypertensive patients, 50 diabetic individuals (25 with and 25 without antihypertensive medication) and 28 healthy volunteers. Mean age, 53 +/- 15 years (range 21-82 years). All participants crossed their legs at knee-level, with the upper part of the popliteal fossa on the suprapatellar bursa, in the sitting position. Differences in mean blood pressure, cardiac output, stroke volume, heart rate and total peripheral resistance were assessed with legs crossed versus legs uncrossed. RESULTS Mean blood pressure [+3.3 +/- 5.5 mmHg; 95% confidence interval (CI) = 2.7-3.8], stroke volume (+7.6 +/- 5.4 ml; 95% CI = 6.7-8.6) and cardiac output (+0.4 +/- 0.9 l/min; 95% CI = 0.3-0.5) were significantly higher with legs crossed than in the uncrossed position, while the heart rate (-1.8 +/- 3.9 beats/min; 95% CI = -2.2 to -1.4) was significantly lower. Total peripheral resistance did not differ significantly (-0.01 +/- 0.16 AU; 95% CI = -0.03 to 0.00). The largest differences occurred in the hypertensive diabetic individuals, the smallest in the healthy volunteers. The changes were similar in men and women. There were no significant correlations in the total group between the differences of the hemodynamic variables and sex, age, body mass index or leg circumference. CONCLUSION The study shows that higher blood pressure with legs in the crossed position is due to higher cardiac output and not to a higher total peripheral resistance.
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Sheriff DD, Nådland IH, Toska K. Hemodynamic consequences of rapid changes in posture in humans. J Appl Physiol (1985) 2007; 103:452-8. [PMID: 17463298 DOI: 10.1152/japplphysiol.01190.2006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tolerance to +G z gravitational stress is reduced when +G z stress is preceded by exposure to hypogravity (fraction, 0, or negative G z). For example, there is an exaggerated fall in eye-level arterial pressure (ELAP) early on during +G z stress (head-up tilt; HUT) when this stress is immediately preceded by −G z stress (head-down tilt; HDT). The aims of the present study were to characterize the hemodynamic consequences of brief HDT on subsequent HUT and to test the hypothesis that an elevation in leg vascular conductance induced by −G z stress contributes to the exaggerated fall in ELAP. Young healthy subjects ( n = 3 men and 4 women) were subjected to 30 s of 30° HUT from a horizontal position and to 30 s of 30° HUT when HUT was immediately preceded by 20 s of −15° HDT. Four bouts of HDT-HUT were alternated between five bouts of HUT in a counterbalanced designed to minimize possible time effects of repeated exposure to gravitational stress. One minute was allowed for recovery between tilts. Brief exposure to HDT elicited an exaggerated fall in ELAP during the first seconds of the subsequent HUT (−17.9 ± 1.4 mmHg) compared with HUT alone (−12.4 ± 1.2 mmHg, P <0.05) despite a greater rise in stroke volume (Doppler ultrasound) and cardiac output over this brief time period in the HDT-HUT trials compared with the HUT trials (thereafter stroke volume fell under both conditions). The greater fall in ELAP was associated with an exaggerated increase in leg blood flow (femoral artery Doppler ultrasound) and was therefore largely (70%) attributable to an exaggerated rise in estimated leg vascular conductance, confirming our hypotheses. Thus brief exposure to −G z stress leads to an exaggerated fall in ELAP during subsequent HUT, owing to an exaggerated increase in estimated leg vascular conductance.
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Affiliation(s)
- Don D Sheriff
- Department of Integrative Physiology, The University of Iowa, Iowa City, Iowa 52242, USA
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