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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

"Efeito do uso da cinta abdominal elástica na função respiratória de indíviduos lesados medulares na posição ortostática" / Effects of an elastic abdominal binder on the respiratory function in individuals with high spinal cord injury at the orthostatic position.

Viviane de Souza Pinho Costa 01 July 2005 (has links)
A lesão medular espinhal está entre as lesões mais graves que uma pessoa pode ter como experiência. Os efeitos pessoais e sociais são profundamente significantes, pois conferem uma incapacidade permanente sobre as pessoas acometidas. Quando acontece uma agressão à medula espinhal, ocorre um déficit na inervação abaixo da lesão, por perda do controle supraespinhal. Muitas são as conseqüências advindas das mudanças ocorridas na mecânica respiratória, conseqüente da lesão medular acima do sexto segmento torácico, como a superficialidade da respiração, ineficiência da tosse e do espirro, alterações do clearence mucociliar e aumento da complacência abdominal. Tais fatores promovem alterações nos volumes, capacidades e pressões respiratórias, dificultando aos indivíduos tetraplégicos e paraplégicos, com lesão torácica alta, serem colocados em pé, com auxílio de dispositivos, como a mesa ortostática. Com o intuito de verificar o efeito do uso da cinta abdominal elástica na função respiratória, em indivíduos lesados medulares, na posição ortostática em angulações de 60° e 60°/90°, foram mensurados, a capacidade vital, volume corrente, pressão inspiratória e expiratória máxima e saturação de oxigênio. Participaram 56 indivíduos, com predomínio do gênero masculino, apresentando média de idade de 35,4 anos e maior freqüência motora de lesão em T4. Estes foram divididos em quatro grupos distintos em relação ao uso ou não da cinta e angulações da mesa ortostática. Os resultados encontrados para os parâmetros avaliados, não demonstraram significância estatística em relação ao uso ou não da cinta abdominal elástica entre os grupos. No entanto, as médias dos grupos com o uso da cinta, apresentaram-se mais altas em todas as avaliações. Podemos considerar que a cinta não interferiu na melhora significativa dos parâmetros respiratórios. Porém, muitos indivíduos referem utilizá-la como um suporte abdominal, proporcionando estabilização na postura do tronco quando em pé. Estudos com ensaios clínicos aleatórios devem ser propostos para mensurar o efeito que a cinta abdominal elástica proporciona aos indivíduos lesados medulares que a utilizam freqüentemente durante o posicionamento ortostático. / Spinal cord injury is one of the most severe injuries that someone can experience. The personal and social impacts are deeply significant as they cause a permanent disability to the injured person. When the spinal cord injury takes place it results in anervous deficit below the injury site by loss of upper spinal control. There are many consequences of the changes to the respiratory biomechanics, due to the injury above the sixth thoracic segment, such as the superficial respiratory capacity, cough and sneeze inefficiency, mucociliary clearance changes and abdominal complacence increase. These complications cause volume, capacity and pressure disturbances that make it difficult to put tetraplegic and paraplegic individuals with high thoracic injury into a standing up position, even with the assistance of devices like the orthostatic table. The vital capacity, the tidal volume, the maximum inspiratory and expiratory pressures and the oxygen saturation were measured to ascertain the effect of the elastic abdominal binder to the respiratory function of individuals with spinal cord injury at the orthostatic position on 60º and 60º/90º angulations. 56 individuals were chosen, mostly men, at the average age of 35.4 and higher motor frequency injury at the T4. They were divided into four different groups according to the binder use and the orthostatic table angulation’s. Results did not show statistic significance to using or not using the binder between the groups. However, the averages of the groups that used the binder were the highest in all the measurements. It can be said that the binder did not interfere to the significant improvement of the respiratory patterns. In spite of that, many people say they prefer to use the binder as an abdominal support that provides stability to the body when they are standing up. Randomized clinic studies should be done to measure the elastic abdominal binder effects provided to the individuals with spinal cord injuries that often use it into the orthostatic position.
42

Rett syndrome, motor development, mobility and orthostatic reactions : loss of function, difficulties and possibilities

Larsson, Gunilla January 2013 (has links)
Rett syndrome (RTT) is a rare, severe neurodevelopmental disorder, which partly develops in a predictable way, and influences many bodily functions. Regression, i.e. loss of earlier achieved abilities, is one of the clinical criteria for RTT. Research on motor function has to some extent focused on this loss, and less on the possibility to keep, regain or develop abilities. RTT is mainly verified in girls/women, and the prevalence of classic RTT in Sweden for girls born between 1965 and 1976 was 1 in 10.000-12.000. Clinical criteria are used for diagnosis, but since 1999 RTT can be confirmed by a genetic test. As there is no cure so far, development of clinical intervention and management is important, and with good treatment it is possible to improve quality of life. The main aim was to acquire more knowledge about motor development in RTT, both, early development, and development over time. Another aim was to study if there were deviating orthostatic reactions when rising from sitting to standing, and during standing, compared with normally developed, healthy people, matched by sex and age. Clinical experience as well as reports from parents showed that some people with RTT had lost abilities, some had been able to keep abilities, and some had been able to learn new abilities after regression. For good results, the person with RTT had to be motivated, and the intervention jointly planned; it was also important to realize that dyspraxia causes dependence on other people’s initiatives. Information about one person with RTT, collected over several years, showed the possibility to develop in some areas over time and the tendency to deteriorate in other areas. Studying orthostatic reactions when rising to standing, and standing for three minutes, revealed that those with RTT mainly had the same reactions as the healthy controls. The quicker initial drop in systolic blood pressure in people with RTT, when rising, has not been documented earlier.   In conclusion, this thesis shows that it is possible for some people with RTT to keep abilities, regain abilities, and also learn new abilities after regression. Since those with RTT recovered their blood pressure in the same way as the healthy controls, there is no reason to recommend limitations in standing, though the quicker initial drop in systolic blood pressure should be noted. The deterioration in walking found in our previous studies does not seem to be due to deviation in orthostatic reactions. Individual analysis, as well as good knowledge about the development of the disorder and variation in its expression, is essential. Since many people with RTT live to adulthood, planning for lifelong intervention and care is most important.
43

Vertikalizavimo poveikis pacientų, patyrusių kaklinės dalies nugaros smegenų sužalojimą, ortostatinėms reakcijoms / The influence of verticalization on ortostatic reactions of the patiens with cervical part spinal cord injuries

Lankauskienė, Vaida 18 June 2008 (has links)
Tyrimo objektas – pacientų, patyrusių kaklinės dalies nugaros smegenų sužalojimą, ortostatinės reakcijos. Pacientų, patyrusių kaklinės dalies nugaros smegenų sužalojimą, ortostatinės reakcijos – viena didžiausių problemų, trukdanti siekti reabilitacijos programos tikslų. Reabilitacijos pradžioje, keičiant kūno padėtį, jiems dažnai svaigsta galva, pykina, gali net prarasti sąmonę. Visi šie simptomai neigiamai veikia pacientą, todėl svarbu šalinti ortostatinių reakcijų pasireiškimą vertikalizuojant kuo anksčiau. Darbo tikslas – nustatyti, kuris vertikalizavimo stovas – įprastas ar ERIGO – veiksmingiau mažina pacientų, patyrusių kaklinės dalies nugaros smegenų sužalojimą, ortostatines reakcijas. Uždaviniai: 1. Įvertinti tiriamųjų kraujospūdžio pokyčius vertikalizavimo metu su skirtingais stovais. 2. Įvertinti tiriamųjų širdies susitraukimo dažnio pokyčius vertikalizavimo metu su skirtingais stovais. 3. Įvertinti pacientų savijautą po vertikalizavimo su skirtingais stovais. 4. Nustatyti vertikalizavimo procedūros su skirtingais stovais toleruojamą trukmę. Hipotezė. ERIGO – vertikalizavimo stovas su mechanizmu pasyviems kojų judesiams – veiksmingiau mažina pacientų, patyrusių kaklinės dalies nugaros smegenų sužalojimą, ortostatines reakcijas. Tyrimo metodika. Tyrime dalyvavo 24 pacientai, kurie gydėsi Palangos reabilitacijos ligoninėje 2007–2008 metais po nugaros smegenų kaklinės dalies sužalojimo. Tiriamieji buvo suskirstyti į dvi grupes po 12 žmonių. Visiems pacientams buvo... [toliau žr. visą tekstą] / Study subject: Orthostatic reactions of the patients with cervical part spinal cord injuries. Orthostatic reactions for patients with cervical part spinal cord injuries is one of the most biggest problems, which disturbs to seek the aims of rehabilitation. Patients often suffer from dizziness, nausea and even might to lose consciousness at the beginning of the rehabilitation. All these symptoms has a negative impact to patients, so it must be reduced as soon as possible. Study aim: To determine which tilt-table- simple or Erigo-has the bigger effect for patient’s, wiht cervical part spinal cord injuries, orthostatic reactions. Study goals: 1. To evaluate the blood pressure changes of the patients during verticalization with different tilt-table; 2. To evaluate the heart rate changes of the patients during verticalization with different tilt-table; 3. To evaluate the state of the patients health after verticalization with different tilt-table; 4. To determine the tolerated duration of the virtualization procedure with different tilt-table. Hypothesis: Erigo - a tilt-table with passive legs movements – is more effective in reducing orthostatic reactions of the patients with cervical part spinal cord injuries. Study methods: The study included 24 patients with cervical part spinal cord injuries which had treatment at Palanga Hospital of Rehabilitation on 2007-2008 year period. Patients were divided in to two equal groups (12 patients in each group). All patients had the same... [to full text]
44

EFFECT OF LOWER BODY POSITIVE PRESSURE ON CARDIOVASCULAR RESPONSE AT VARIOUS DEGREES OF HEAD UP TILT

Kostas, Vladimir Ilyich 01 January 2012 (has links)
Various models of simulated weightlessness and resulting cardiovascular effects have been researched in the last 50 years of space exploration. Examples of such models are the Alter-G (Alt-G) treadmill used for body unweighting and head-up-tilt (HUT) model each providing similar cardiovascular effects, but differing in their stimulation of vestibular centers . Advantages of using the Alt-G include: use of lower body positive pressure (LBPP) to simulate hypogravity, it acts as a countermeasure to alleviate negative cardiovascular effects of standing and provides a constant vestibular stimulus. In addition, the Alt-G shorts themselves may be providing a certain degree of LBPP, acting as a compression garment. Therefore the purpose of this study was to determine the cardiovascular effects of Alt-G shorts and how effective they are as countermeasure to deconditioning effects of space flight. This study tested cardiovascular changes in 12 men and women at 0 and 80 degrees head-up-tilt (HUT0 / HUT80) with and without Alt-G shorts using 5-lead ECG, 10-lead impedance, heart rate, systolic and diastolic blood pressure measurements at finger and arm. The tilt-induced increase in mean heart rate (HR) was significantly smaller when subjects wore the Alt-G shorts. Shorts ended up reducing HR by 2.3 bpm in supine control and by 6.7 bpm at HUT80 (p0.05. Other cardiovascular variables did not show any significant effect from shorts. In conclusion, this study was in line with results from other studies that used compression garments to determine cardiovascular effects of LBPP.
45

Training for Old Age: Production Functions for the Aerobic Exercise Inputs

Everett, Michael D., Kinser, Ann M., Ramsey, Michael W. 01 December 2007 (has links)
Purpose: This paper attempts to develop production functions (PF) between aerobic exercise inputs and long-run health outputs. Future studies could use such PF for estimating the benefits and costs (broadly defined) of different exercise programs to help develop optimal (utility maximizing) ones. Methods: To develop the PF, the paper reviewed the biomedical literature for the major dose-response relations between health, physical fitness, and exercise. Where relevant, the paper converted the dose-response relationships from relative risks to absolute probabilities and standardized terminology and units of measures. Results: The paper develops a clear set of biological PF that illustrate, quantitatively, how increases in peak cardiorespiratory (CR) fitness as measured by a short stress test reduce the probability of all-cause mortality; how increasing intensities of short (approximately 30 min, three to five times a week) exercise sessions increase peak CR fitness or retard its age-related decline; and how consistent exercise reduces the risk of myocardial infarctions (MI). Conclusions: The exercise-long-run health PF developed in this paper should provide a useful framework for other studies to estimate the broadly defined costs and benefits of different exercise programs and to help develop optimal ones.
46

Selektive Hemmung der Noradrenalin-Wiederaufnahme als humanes Modell für orthostatische Intoleranz

Schröder, Christoph 20 January 2003 (has links)
Hintergrund. Untersuchungen bei Patienten mit funktionellen Mutationen des Noradrenalin-Transporter-Gens deuten darauf hin, dass eine verminderte Noradrenalin-Wiederaufnahme zur Pathophysiologie der idiopathischen Orthostatischen Intoleranz beitragen kann. Methoden. In einer doppeltblinden, placebokontrollierten, randomisierten Studie wurden die kardiovaskulären Effekte einer selektiven pharmakologischen Noradrenalin-Wiederaufnahmehemmung (2x 8 mg Reboxetin p.o.) bei gesunden Testpersonen untersucht. In der ersten Teilstudie (n=23) wurden autonome Funktionstests und eine Kipptischuntersuchung durchgeführt. Herzfrequenz, Blutdruck und zerebrale Blutflussgeschwindigkeit wurden dabei kontinuierlich nicht-invasiv gemessen. Herzzeitvolumen und peripherer Widerstand wurden impedanzkardiografisch bestimmt. In einer zweiten Teilstudie (n=10) wurde der Effekt akuter selektiver Noradrenalin-Wiederaufnahmehemmung auf die Sensitivität gegenüber blutdruckwirksamer Pharmaka getestet. Dafür wurden steigende intravenöse Dosen von Phenylephrin, Isoproterenol und Nitroprussid gegeben und die Änderungen von Blutdruck und Herzfrequenz in individuellen Dosis-Wirkungskurven bestimmt. Ergebnisse. Unter Noradrenalin-Wiederaufnahmehemmung waren Herzfrequenz und Blutdruck im Liegen erhöht. Während der Kipptischuntersuchung führte die Noradrenalin-Wiederaufnahmehemmung zu einer deutlich gesteigerten Herzfrequenz (120+/-3 /min vs. 83+/-3 /min unter Placebo, p / Background. Observations in patients with functional mutations of the norepinephrine transporter (NET) gene suggest that impaired norepinephrine uptake may contribute to idiopathic orthostatic intolerance. Methods. In a double-blind, placebo-controlled, and randomized crossover study we investigated the cardiovascular effects of acute selective pharmacological inhibition of the norepinephrine transporter (2x 8mg reboxetine p.o.) on healthy volunteers. Autonomic function test and a graded head-up tilt test were performed (n=23). Heart rate, blood pressure and cerebral blood flow velocity were measured non-invasively and continuously. Cardiac output and peripheral resistance were measured by impedance cardiography. In a smaller subset of volunteers (n=10) we also investigated the effects of acute inhibition of the Norepinephrine transporter on the sensitivity to pressor and depressor agents. Therefore, increasing doses of phenylephrine, isoproterenol, and nitroprusside were administered intravenously and individual dose-response-curves were plotted. Results. Norepinephrine reuptake inhibition increased both, supine heart rate and blood pressure. During head-up tilt, heart rate was profoundly increased with norepinephrine reuptake inhibition (120+/-3 /min vs. 83+/-3 /min with placebo, p
47

Možnosti ovlivnění krevního tlaku při vertikalizaci pacientů s míšní lézí / Possibilities of influencing blood pressure in spinal cord injury patients during verticalization

Věchetová, Tereza January 2012 (has links)
Orthostatic hypotension is a common problem for individuals with spinal cord lesions, especially in the acute period after spinal cord injury. The first part of this study deals with the theoretical analysis of the pathophysiology of cardiovascular control after spinal cord injury, the definition of orthostatic hypotension and its inclusion within the classification of the syncopal conditions. An important part of the theoretical part is the management of orthostatic hypotension, which brings non-pharmacological therapeutic approaches, and marginally pharmacology, to decrease the severity of this condition. The experimental part focuses on testing of a group of probands with spinal cord injury (11 quadriplegics) on two different types of tilt tables according to the same protocol. The first tilt table is a standard; the second one is Erigo, tilt table with integrated robotic mechanism, which moves the legs to simulate walking. The parameters, such as blood pressure, heart rate, oxygen saturation, and the occurrence and severity of pre-synkopal symptoms, were compared. The study is based on the assumption that passive leg movement, which is mediated by the Erigo, will maintain venous return, cardiac output, and a significant drop in blood pressure and development of orthostatic hypotension,...
48

Dysfonctions neuromusculaires et cardiovasculaires dans les troubles posturaux orthostatiques induits par la microgravité / Нейромышечные и сердечно-сосудистые нарушения при ортостатической и позной неустойчивости, обусловливаемые микрогравитацией

Dmitrieva, Liubov 20 September 2018 (has links)
Les atteintes posturales sont des conséquences connues du vol spatial. Un des facteurs de stabilité orthostatique et postural est le tonus musculaire, qui chute en microgravité. Les études sur les effets cardiovasculaires, neuromusculaires et posturaux de la microgravité sont nombreuses ; pourtant, le rôle des troubles neuromusculaires et cardiovasculaires dans l’atteinte orthostatique et posturale reste peu connu. Notre but était d’étudier des altérations vasculaires et neuromusculaires induites par la microgravité, ainsi que les liens entre eux. Nos études chez l’homme comprenaient un vol spatial de 6 mois, un alitement antiorthostatique de 21 jours et une immersion sèche de 3 à 5 jours. Ces conditions diffèrent par le niveau de stimulation d’appui. L'état cardiovasculaire a été évalué par des tests orthostatiques, neuromusculaire - par myotonométrie et la stabilité posturale - par stabilométrie. Notre travail montre qu’un vol de longue durée induit des troubles bien plus profonds que la microgravité simulé plus courte. De plus, l'immersion sèche induit des troubles plus graves que l'alitement, malgré sa durée plus courte. Nos données suggèrent que c'est la décharge d’appui qui définit la profondeur des perturbations. Le rôle principal de la diminution du tonus des muscles posturaux est mis en avant. Cette diminution se produit par voie réflexe par diminution d’afferentation des zones d’appui. Elle pourrait être responsable de l’intolérance orthostatique via la diminution de l'efficacité de la pompe musculaire favorisant le retour veineux, et de l’instabilité posturale - via l'augmentation des seuils de recrutement des motoneurones posturaux. / Postural and orthostatic impairment are both acknowledged consequences of spaceflight. One of the factors for orthostatic and postural stability is muscle tone, which decreases within the onset of microgravity. Studies of cardiovascular, neuromuscular and postural effects of microgravity are numerous ; yet the role of neuromuscular and vascular disorders in orthostatic and postural impairment remains unclear. We aimed to investigate vascular and neuromuscular alterations induced by microgravity, as well as their relationships. We studied healthy men exposed to 6-mo spaceflight, 21-day head-down bedrest and 3-to 5-day dry immersion. These conditions differ by the level of support unloading. Cardiovascular state was assessed by orthostatic tests, neuromuscular - by myotonometry, postural stability - by stabilometry. We found that long-term spaceflight induced much deeper disorders than relatively short-term modeled microgravity. Furthermore, immersion induced more severe disorders than bedrest, despite its shorter duration. Our data, along with literature, suggest that it is the support unloading that defines the depth of disturbances. The leading role in development of postural disorders under gravitational unloading belongs to decrease in postural muscle tone. This decrease occurs mainly by a reflex mechanism (decrease in support afferentation). It might be responsible for orthostatic impairment - via decrease in the efficiency of muscle pump promoting venous return, and for postural impairment - via increase in recruitment thresholds of postural motoneurons.
49

Efeitos da suplementação de sal na profilaxia da síncope vasovagal : ensaio clínico randomizado

Kuhmmer, Regina January 2007 (has links)
Introdução: Síncope e sintomas ortostáticos são comuns em pessoas saudáveis. A suplementação de sal é utilizada em pacientes com melhora na resposta pressora e aumento da tolerância ortostática. Nós testamos à hipótese de que uma suplementação de sal aumentaria a tolerância ortostática em voluntários saudáveis. Métodos e Resultados: Vinte voluntários saudáveis (13 do sexo feminino, idade 29 ± 5,6 anos), sem história de síncope, foram submetidos ao teste inclinação ortostática, em um ângulo de 70 graus, por 35 minutos ou até que sintomas de pré-síncope ou síncope fossem observados. Foram randomizados e cruzados para receber 6g de sal em um dos exames e placebo no outro, 3 horas antes, em um protocolo duplo-cego. Para avaliar para-efeitos, foram avaliados índices clínicos e laboratoriais. A ingestão de sal melhorou a tolerância ortostática em 11 de 12 voluntários (55%) que apresentaram présincope ou síncope (variação de 1 a 6 minutos). O tempo com a suplementação de sal foi de 33,35 ± 4,1 minutos e com placebo 31,95 ± 4,4 minutos (média ± DP; p = 0,009), a tolerância ortostática diferiu em 1,4 ± 2,09 minutos (IC 95%, 0,42 - 2,37 minutos). A pressão arterial sistólica, a diastólica e a freqüência cardíaca na posição supina não alteraram de forma significativa. No entanto, a pressão arterial sistólica e a diastólica (120,85 ± 30,9 e 78,75 ± 20,6 mmHg) mantiveram-se mais elevadas ao término do exame com a suplementação de sal quando comparadas com o placebo (99,2 ± 29,8 e 64 ± 21 mmHg; p = 0,006 e p = 0,007, respectivamente). Conclusão: A suplementação de sal parece melhorar a tolerância ortostática em voluntários saudáveis, sem alterar as variáveis clínicas em repouso. / Background: Orthostatic symptoms and syncope are common in healthy subjects. Salt supplementation can be used in patients showing improvement in the pressor response and increase in the orthostatic tolerance. We tested the hypothesis that single salt supplementation increases the orthostatic tolerance in healthy subjects. Methods e Results: Twenty healthy volunteers (13 females, 29.05 ± 5.57 years old), without syncope history, were submitted to head-up tilt test, at an angle of 70 degrees, for 35 minutes or until presyncope or syncope were observed. They were randomized and crossover to receive 6g of salt in one of the exams and placebo in the other, 3 hours before, in a double-blind protocol. To evaluate for side effects, there were evaluate clinical and laboratorial indexes. Ingestion of salt improved orthostatic tolerance in 11 out of 12 volunteers who presented presyncope or syncope (variation from 1 to 6 minutes). The time with salt supplementation was of 33.35 ± 4.1 minutes and with placebo it was of 31.95 ± 4.4 minutes (mean ± SD; p = 0.009), orthostatic tolerance differed in 1.4 ± 2.09 minutes (95% CI, 0.42 - 2.37 minutes). Systolic and diastolic blood pressure and heart rate in the supine position did not change significantly with salt or with the placebo. However, Systolic and diastolic blood pressure with salt supplementation (120.85 ± 30.9 mmHg and 78.75 ± 20.6 mmHg) were higher at the end of the exam when compared to placebo (99.2 ± 29.8 and 64 ± 21 mmHg; p = 0.006 and p = 0.007, respectively). Conclusion: Salt supplementation seems to improve orthostatic tolerance in healthy volunteers without changing clinical variables at rest.
50

Efeitos da suplementação de sal na profilaxia da síncope vasovagal : ensaio clínico randomizado

Kuhmmer, Regina January 2007 (has links)
Introdução: Síncope e sintomas ortostáticos são comuns em pessoas saudáveis. A suplementação de sal é utilizada em pacientes com melhora na resposta pressora e aumento da tolerância ortostática. Nós testamos à hipótese de que uma suplementação de sal aumentaria a tolerância ortostática em voluntários saudáveis. Métodos e Resultados: Vinte voluntários saudáveis (13 do sexo feminino, idade 29 ± 5,6 anos), sem história de síncope, foram submetidos ao teste inclinação ortostática, em um ângulo de 70 graus, por 35 minutos ou até que sintomas de pré-síncope ou síncope fossem observados. Foram randomizados e cruzados para receber 6g de sal em um dos exames e placebo no outro, 3 horas antes, em um protocolo duplo-cego. Para avaliar para-efeitos, foram avaliados índices clínicos e laboratoriais. A ingestão de sal melhorou a tolerância ortostática em 11 de 12 voluntários (55%) que apresentaram présincope ou síncope (variação de 1 a 6 minutos). O tempo com a suplementação de sal foi de 33,35 ± 4,1 minutos e com placebo 31,95 ± 4,4 minutos (média ± DP; p = 0,009), a tolerância ortostática diferiu em 1,4 ± 2,09 minutos (IC 95%, 0,42 - 2,37 minutos). A pressão arterial sistólica, a diastólica e a freqüência cardíaca na posição supina não alteraram de forma significativa. No entanto, a pressão arterial sistólica e a diastólica (120,85 ± 30,9 e 78,75 ± 20,6 mmHg) mantiveram-se mais elevadas ao término do exame com a suplementação de sal quando comparadas com o placebo (99,2 ± 29,8 e 64 ± 21 mmHg; p = 0,006 e p = 0,007, respectivamente). Conclusão: A suplementação de sal parece melhorar a tolerância ortostática em voluntários saudáveis, sem alterar as variáveis clínicas em repouso. / Background: Orthostatic symptoms and syncope are common in healthy subjects. Salt supplementation can be used in patients showing improvement in the pressor response and increase in the orthostatic tolerance. We tested the hypothesis that single salt supplementation increases the orthostatic tolerance in healthy subjects. Methods e Results: Twenty healthy volunteers (13 females, 29.05 ± 5.57 years old), without syncope history, were submitted to head-up tilt test, at an angle of 70 degrees, for 35 minutes or until presyncope or syncope were observed. They were randomized and crossover to receive 6g of salt in one of the exams and placebo in the other, 3 hours before, in a double-blind protocol. To evaluate for side effects, there were evaluate clinical and laboratorial indexes. Ingestion of salt improved orthostatic tolerance in 11 out of 12 volunteers who presented presyncope or syncope (variation from 1 to 6 minutes). The time with salt supplementation was of 33.35 ± 4.1 minutes and with placebo it was of 31.95 ± 4.4 minutes (mean ± SD; p = 0.009), orthostatic tolerance differed in 1.4 ± 2.09 minutes (95% CI, 0.42 - 2.37 minutes). Systolic and diastolic blood pressure and heart rate in the supine position did not change significantly with salt or with the placebo. However, Systolic and diastolic blood pressure with salt supplementation (120.85 ± 30.9 mmHg and 78.75 ± 20.6 mmHg) were higher at the end of the exam when compared to placebo (99.2 ± 29.8 and 64 ± 21 mmHg; p = 0.006 and p = 0.007, respectively). Conclusion: Salt supplementation seems to improve orthostatic tolerance in healthy volunteers without changing clinical variables at rest.

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