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.

Actuellement, l’étude du mouvement des tissus biologiques figure parmi les thématiques majeures dans le domaine de l’imagerie médicale, dont le challenge est d’apporter un complément d’information clinique et de permettre une aide au diagnostic. L’application récente de techniques d’élastographie ouvre de nouvelles perspectives de caractérisation biomécanique des tissus, et notamment du cerveau. Dans ce contexte, nous proposons une méthodologie innovante d’élastographie passive des propriétés mécaniques du tissu cérébral dont le but est de permettre à terme le diagnostic des maladies neurodégénératives. / The study of biological tissues movement is currently, one of the major thematics in the medical imaging field. The challenge is to provide additional clinical information and allow for diagnostic assistance. The recently introduced elastographic techniques, provide ample opportunities for biomechanical tissues characterization, particularly of cerebral tissues. An innovative passive-elastographic methodology for assessing mechanical properties of brain tissue is proposed. The eventual aim is to allow for the diagnosis of neurodegenerative diseases.

No description available.

This mixed-media memoir uses a variety of forms from short epigrammatic essays to straightforward stories and graphic narratives to explore the author’s coming-of-age experiences augmented by chronic illness. Trying to succeed in the film industry, romance, and family situations, the young female narrator navigates the often unexpected or disappointing consequences of having an autonomic nervous system disorder. Relationships between conflicting identities emerge—between healthy versus sick self, projected/envisioned versus actual self, and tough versus vulnerable self—as the narrator journeys toward a more complete and accepting self-understanding.

Chronic illness and invisible disability are impactful contexts during emerging adulthood and the launching stage of the family life cycle (Beatty, 2011; Capelle, Visser, and Vosman, 2016; Young et al., 2010). The parent-child relationship is important to both developmental and health outcomes in families coping with chronic illness during emerging adulthood (Crandell, Sandelowski, Leeman, Haville, and Knafle, 2018; Fenton, Ferries, Ko, Javalkar, and Hooper, 2015; Waldboth, Patch, Mahrer-Imhaf, and Metcalfe, 2016). While informed clinical competency in counseling families experiencing disablement is a diversity-affirmative ethical imperative among psychotherapists (Mona et al., 2017), little is known in family therapy about how parents and emerging adult children experience launching with chronic illness. This qualitative study explored the parent-child dyadic experience of living with a chronic illness called Postural Orthostatic Tachycardia Syndrome (POTS) during emerging adulthood. Seven dyads of parents and their emerging adult children with POTS were interviewed. Data analysis of in-depth interviews using Moustakas's (1994) transcendental phenomenology uncovered eight thematic clusters of meaning in the shared lived experience of POTS at the launching stage of the family life cycle. Clinical implications for family therapists were explored using Rolland's family system-illness (FSI) model of medical family therapy. Study limitations and future directions for further research were discussed. / Master of Science / More and more young adults are living with chronic illness. Postural Orthostatic Tachycardia Syndrome (POTS) is a little-known chronic illness that tends to begin during adolescence. Like many health problems that disproportionately affect women, POTS is often overlooked by doctors. POTS symptoms, such as dizziness and cognitive difficulty, impact a person's ability to engage in preferred activities and identities. Family therapists can play an impactful role in supporting parents and children with POTS through developmental tasks related to launching an emerging adult in the context of this complex and widely misunderstood chronic illness. This thesis presented the first qualitative study of parent-child dyadic experiences living with POTS. Clinical implications for medical family therapy were highlighted. To construct an interview framework, Rolland's Family Systems-Illness (FSI) clinical model for helping families cope with illness and disability was used in conjunction with Arnett's description of emerging adulthood as a developmental stage in life. Seven parent-child dyads were interviewed for 1-2 hours in fourteen separate interviews generating transcripts about 140,000 words long in total. Analysis of these interviews identified shared themes composing the essence of the parent-child experience living with POTS during emerging adulthood. Results were described through tables and narratives. Clinical implications for family therapists working with parents and children with POTS during emerging adulthood were proposed. Limitations and ideas for future studies were discussed.

L’encéphalomyélite myalgique (EM) est une maladie complexe, multi-systémique et débilitante, dont l’étiologie est inconnue. D’une personne atteinte d’encéphalomyélite myalgique (PAEM) à l’autre, les symptômes varient en fréquence et en sévérité créant ainsi une grande hétérogénéité clinique entre les individus. Un sous-groupe de PAEM vivent des épisodes d’intolérance orthostatique (IO) ou vivent avec une comorbidité de syndrome de tachycardie orthostatique posturale (POTS), deux conditions qui sont mal comprises. Le malaise après-effort (PEM), un des symptômes phare de l’EM, survient après une activité physique ou mentale minimale. Le malaise après-effort entraîne une dégradation générale de l’état de l’individu, peut entraîner une exacerbation des autres symptômes et va durer de plusieurs heures à plusieurs jours. Chez les individus souffrant de POTS ou d’IO, le malaise après-effort peut déclencher des épisodes d’intolérance orthostatique. Le gène SLC6A2 codant pour le transporteur de norépinephrine NET a été identifié comme potentiel mécanisme dans pathophysiologie du POTS, tout comme les protéines impliquées dans la vasodilatation, comme la thrombospondine-1 (TSP-1). Notre laboratoire a identifié un panel de onze microARN (miARN) exprimés différentiellement chez les PAEM. Parmi ceux-ci, le miR-150-5p a comme cible prédite SLC6A2. Notre hypothèse était qu’une plus grande expression du miR-150-5p après un effort ou qu’une chute de thrombospondine-1 pourrait induire une vasodilatation soudaine contribuant aux symptômes d’IO ou de POTS. Nous avons mesuré les niveaux plasmatiques du miR-150-5p et de TSP-1 avant (T0) et après (T90) l’induction du malaise après-effort chez des PAEM avec POTS/IO (n = 20), chez des PAEM sans POTS/IO (n = 117) et chez des témoins sédentaires associés pour le sexe et l’âge (n = 48). Nous avons démontré que les sujets atteints de POTS/IO avaient des niveau plus importants du miR-150-5p et des symptômes plus sévères. Finalement, nous avons également utilisé la veste intelligente Hexoskin (Carré Technologies Inc., Montreal, Qué., Canada) pour suivre un sous-groupe d’individus (n = 10) sur une plus longue période après l’induction du malaise après-effort. Avec cet outil, nous avons pu monitorer les symptômes au quotidien, permettant un meilleur suivi clinique de ces patients. Ce projet de maîtrise a permis une meilleure compréhension de la pathophysiologie de l’EM et de celle du POTS. / Myalgic encephalomyelitis (ME) is a complex chronic disease with debilitating smyptoms and unknown etiology. Symptoms vary in frequency and severity from a person with ME (PwME) to another, thus creating a highly clinically heterogeneous patient population. Some PwME also experience orthostatic intolerance (OI) episodes or live with a comorbidity of postural orthostatic tachycardia syndrome (POTS), two conditions that are not well understood. Post-exertional malaise (PEM) causes patients to experience a worsening of their symptoms following an effort, whether it be physical or mental. PEM can last from a few hours to several days. In PwME with POTS/OI, PEM can trigger orthostatic intolerance episodes. SLC6A2 is a gene coding for the norepinephrine transporter NET. Its contribution to the POTS pathophysiology has been mentioned several times in literature. A biochemical milieu prone to vasodilation was also reported as a contributing element to POTS pathophysiology. Recently, our laboratory published an article identifying a panel of eleven microRNAs (miRNAs) differentially expressed in PwME. Among these miRNAs, miR-150-5p has been predicted to target SLC6A2. Our hypothesis was that higher expression of miR-150-5p following an effort or a decrease in circulating thrombospondin-1 (TSP-1) inducing vasodilation could contribute to POTS/OI symptoms. We measured circulating levels of miR-150-5p and TSP-1 before (T0) and after (T90) PEM induction in PwME (n = 117), PwME with POTS/OI (n = 20) and age and sex matched sedentary controls (n = 48). We demonstrated that PwME with POTS/OI have higher levels of miR-150-5p at both T0 and T90, while also having more severe symptoms. Furthermore, we used the connected vest Hexoskin (Carré Technologies Inc., Montreal, Qué., Canada) to follow a subgroup (n = 10) of patients for a longer period following PEM induction. With this tool, we were able to monitor symptoms on a daily basis, allowing better clinical follow-up. Overall, this project allowed better understanding of ME and POTS’ pathophysiology.

L'encéphalomyélite myalgique (EM) est une maladie chronique complexe et hétérogène dont l'étiologie et la physiopathologie restent mal comprises. Cette maladie comporte une multitude de symptômes et se caractérise par une fatigue constante inexpliquée, non soulagée par le repos et un malaise post-effort (MPE), qui se traduit par une aggravation des symptômes à la suite d’une activité physique ou cognitive minimale. Bien que le MPE soit le symptôme caractéristique de l'EM, plusieurs symptômes peuvent varier au fil du temps selon les personnes affectées en termes de fréquence et d'intensité. Environ 60 % des personnes atteintes d'EM souffrent d’une dysautonomie, plus fréquemment d’une intolérance orthostatique (IO) et, souvent, d’un syndrome de tachycardie orthostatique posturale (STOP). L’IO et le STOP sont déclenchés par un changement de position de couché à debout et sont aggravés par le MPE. Les patients gravement atteints par l’EM sont confinés à la maison et souvent cloués au lit. L'EM est une maladie qui affecte globalement des millions de personnes, incluant plus de 500,000 Canadiens. Cependant, le nombre de personnes souffrant de cette maladie pourrait en fait être une sous-représentation de la réalité car environ 84 à 91 % d’entre elles ne sont toujours pas diagnostiquées. Le diagnostic de l’EM est difficile en raison du manque de biomarqueurs validés et du chevauchement dans les symptômes avec d'autres maladies telles que la fibromyalgie (FM). La FM est une autre maladie chronique dont l'étiologie demeure inconnue avec une prévalence d'environ 2 à 3 % de la population et présente plusieurs symptômes en commun avec l'EM, tels que la fatigue, les problèmes de sommeil et les troubles cognitifs. Alors que l'EM est davantage caractérisée par la MPE, la FM est associée aux douleurs chroniques, à un faible seuil de douleur et à une sensibilité musculaire. Avec des preuves à l’appui et compte tenu de la nature hétérogène de l’EM, il est reconnu que la pathogénèse de cette maladie est le résultat d’une combinaison de facteurs. D’abord, il y a les prédispositions génétiques, car souvent plusieurs membres de la famille sont atteints. Ensuite, il y a les expositions environnementales telles que les toxines, les moisissures, l’exposition aux métaux lourds (mercure, arsenic, etc.). De plus, les infections par des agents pathogènes viraux (H1N1, EBV, etc.) ou bactériens (Borrelia burgdorferi), ainsi que des stress majeurs peuvent jouer un rôle comme agent déclencheur dans la maladie. Les microARN (miARN) sont une classe de petits ARN non codants qui possèdent la capacité de réguler l'expression de plusieurs gènes et ont donc un impact considérable sur les fonctions physiologiques. Il est important de noter que l’expression de nombreux miARN est modulée par les facteurs génétiques, épigénétiques et environnementaux. Nous proposons que les miARN jouent un rôle dans la pathogenèse de l'EM en modulant plusieurs voies physiologiques dont la réponse au stress. L'objectif général de cette thèse était d'examiner le rôle des miARN dans la physiopathologie de l'EM et leur contribution dans la variabilité et à la gravité des symptômes. Dans le premier article, nous avions pour objectif d’identifier les miARN impliqués dans l’EM. Ceci nous a conduit à découvrir 11 miARN circulants qui sont dérégulés et associés au MPE déclenché par l'application d'une provocation standardisée. Basé sur les changements d’expression de ces miARN après un stress appliqué provoquant un MPE chez les participants EM, nous avons pu créer un algorithme capable de différentier avec succès les individus EM des témoins sains. De plus, en utilisant le regroupement k-means, nous avons identifié quatre sous-groupes distincts de patients atteints d'EM présentant des profils de miARN et une gravité de la maladie différents. Parmi les 11 miARN identifiés, l'expression dérégulé de hsa-miR-29a-3p, hsa-miR-150-5p et hsa-miR-374b-5p avait été précédemment associée à la FM dans la population norvégienne. L'objectif du deuxième article était d'évaluer les niveaux d'expression des 11 miARN associés à l'EM chez les patients atteints de FM ainsi que chez ceux présentant un diagnostic comorbide d'EM et de FM (EM+FM). Nous avons observé des signatures d'expression différentielles des 11 miARN entre les individus EM, FM et EM+FM. Ces résultats nous ont permis de développer un modèle de prédiction basé sur une approche d’apprentissage automatique, capable de différentier les maladies EM et FM. L'un des miARN identifiés dans notre panel diagnostic d’EM, hsa-miR-150-5p, est prédit de réguler l'expression du gène SLC6A2 codant pour le transporteur de norépinephrine (NET). L’inactivation du transporteur NET a été mise en évidence par la découverte de mutations inactivatrices associées à une forme familiale rare de STOP ce qui n’est pas le cas pour la majorité des personnes atteintes de STOP. Néanmoins, chez ces personnes le niveau de la protéine NET et son expression sont souvent réduites. L'objectif du troisième manuscrit était d'étudier l'implication de miR-150-5p dans le STOP et IO survenant chez les personnes souffrant d'EM, EM+FM et STOP sans EM ni FM. Dans cette étude, nous avons confirmé une élévation du taux plasmatique de norépinephrine chez les participants atteints de STOP (avec et sans EM), suggérant une réduction de la protéine NET. Parmi les patients atteints d'EM avec STOP/IO et les patients STOP uniquement (sans EM), nous avons déterminé un mécanisme double par lequel le STOP est déclenché, centré sur deux profils distincts impliquant des taux plasmatiques faibles et élevés de miR-150-5p. Nous avons réalisé des expériences in vitro permettant de moduler les niveaux d’expression du miR-150-5p dans la lignée cellulaire SH-SY5Y, et mis en évidence une augmentation de l'expression du gène SLC6A2 suggérant un mécanisme indirect impliquant une réduction significative dans les niveaux de protéine EZH2, un puissant répresseur transcriptionnel de SLC6A2 et une autre cible confirmée de miR-150-5p. Dans cette thèse, nous avons identifié un panel diagnostic constitué de 11 miARN circulants qui, grâce à une combinaison d'un test d'effort, peuvent aider au diagnostic des individus atteints d'EM et révéler de nouvelles informations sur la physiopathologie de l'EM. De plus, ce panel de miARN peut être utilisé pour différentier les conditions de EM, FM et EM+FM, ce qui est vital pour la compréhension de la physiopathologie de chaque maladie. Finalement, nous proposons un nouveau mécanisme par lequel l'altération de miR-150-5p peut déclencher le STOP/IO chez les individus atteints d'EM, EM+FM ainsi que chez ceux souffrant de STOP sans EM. Le diagnostic précis des individus à l'aide des miARNs en tant que biomarqueurs aidera à déterminer des mesures préventives, à établir des traitements efficaces et à identifier des cibles thérapeutiques pour la maladie EM par une manipulation directe ou indirecte de l'expression des miARN. / Myalgic encephalomyelitis (ME) is a complex chronic heterogeneous illness whose etiology and pathophysiology remain poorly understood. This disease has a multitude of symptoms, and it is characterised by unexplained constant fatigue unrelieved by rest and post-exertional malaise (PEM), which is reported as a worsening of symptoms following a minimal physical or cognitive activity. While PEM is the hallmark symptom of ME, some symptoms can vary overtime among affected individuals in frequency and intensity. About 60% of people with ME experience autonomic dysfunctions often refereed as dysautonomia and can result in orthostatic intolerance (OI) and in some cases in Postural Orthostatic Tachycardia Syndrome (POTS). Both OI and POTS are triggered by a change of position from supine to standing and are worsened by PEM. Severely affected patients are housebound and often bedridden. ME is common in all populations and it is known to affect over 500,000 Canadians. However, the number of people suffering from this disease may be in fact an underrepresentation of the reality because about 84-91% remain undiagnosed. Diagnosis is challenging due to a lack of validated biomarkers and overlap in symptoms with other diseases such as Fibromyalgia (FM). FM is another chronic illness with unknown etiology with a prevalence of about 2-3% of the population and has several common symptoms with ME such as fatigue, sleep problems and cognitive impairment. While ME is more characterised by PEM, FM is associated with more chronic pain, low pain threshold and muscle tenderness. With supporting evidence and the heterogeneous nature of ME, it is evident that the pathophysiology of this disease includes a combination of factors. First of all, there are predisposing genetic factors since it is common to observe several affected family members. Then, there are environmental exposures such as toxins, mold, exposure to heavy metals (mercury, arsenic, etc.). In addition, viral pathogen infections (H1N1, EBV, etc.) or bacterial infections (Borrelia burgdorferi) as well as major stress can play a role as a triggering agent in the disease. MicroRNAs (miRNAs) are a class small non-coding RNAs that possess the ability to regulate the expression of several genes and therefore greatly impact physiological functions. Of note, the expression of many miRNAs is modulated by genetic, epigenetic, and environmental factors. We propose that miRNAs play a role in the pathogenesis of ME by modulating several physiological pathways particularly in response to stress. The general objective of this thesis was to examine the role of miRNAs in the pathophysiology of ME and their contribution to symptom variability, and severity. In firstly paper, we aimed to determine the miRNAs involved in ME disease. We have identified using microarray technology and confirmed by qPCR a panel of 11 circulating miRNAs that are deregulated and associated with PEM in response triggered by the application of a standardized provocation maneuver. Based on the changes of those miRNAs due to the applied stress test that provokes PEM in ME participants, we were able to create an algorithm capable of successfully differentiate ME individuals from healthy controls (HC). In addition, using k-means clustering, we have identified four distinct subgroups of ME patients with different miRNA profiles and severity of the disease. Among the selected 11 miRNAs, hsa-miR-29a-3p, hsa-miR-150-5p and hsa-miR-374b-5p downregulated expression was previously associated with FM in the Norwegian population. The objective of the second paper was to investigate the expression levels of the 11 associated miRNAs with ME in FM patients as well as those with a comorbid diagnosis of ME and FM (ME+FM). We observed differential expression signatures of the 11 miRNAs between ME, FM and ME+FM individuals. These results prompted us to develop a prediction model based on machine learning approach, which can differentiate ME and FM illnesses. One of the miRNAs identified in our ME diagnostic panel, hsa-miR-150-5p is predicted to regulate the expression of SLC6A2 gene encoding norepinephrine transporter (NET). Inactivation of NET transporter by mutations was discovered in rare familial form of POTS which is not the case for most people with POTS. Nevertheless, in these people the level of the NET protein and its expression are often reduced. The objective of the third manuscript was to investigate the implication of miR-150-5p in POTS and OI occurring in people suffering of ME, ME+FM and POTS without ME or FM. In this study, we confirmed an elevation of plasma norepinephrine in participants with POTS (with and without ME), suggesting a reduction in NET protein. Among ME patients with POTS/OI, and POTS-only patients (without ME), we determined a dual mechanism by which POTS is triggered centered on two distinct profiles involving low and high plasma miR-150-5p levels. We performed in vitro experiments and with modulation of miR-150-5p expression levels in SH-SY5Y cells line, we observe an increase in SLC6A2 expression, suggesting an indirect mechanism involving a significant reduction in levels of EZH2 protein, a powerful transcriptional repressor of SLC6A2 and another confirmed target of miR-150-5p. In this thesis, we have identified a panel of circulating miRNAs, which in combination to a stress test, can aid in the accurate diagnosis of ME individuals and reveal new insights into the ME pathophysiology. In addition, this panel of miRNAs at baseline can be used to differentiate ME from FM or when it co-exists with the ME (ME+FM), which is crucial for understanding the pathophysiology of each illness. And finally, we propose a first mechanism by which alteration of miR-150-5p can trigger POTS/OI in individuals with ME, ME+FM as well as in those suffering of POTS without ME. The accurate diagnosis of individuals with the help of miRNAs as biomarkers will help to establish preventive measures, effective treatments, and therapeutic targets for ME disease by a direct or indirect manipulation of miRNA expression.

INTRODUÇÃO: Informações da literatura associam a obesidade a maior atividade simpática. A gastroplastia com derivação gastrojejunal em Y de Roux, que leva a redução rápida e intensa do peso, pode influenciar o padrão autonômico cardiovascular. O objetivo deste estudo é avaliar os efeitos dessa cirurgia sobre a modulação autonômica do coração, tolerância ortostática e excreção urinária de noradrenalina. METODOS: Trata-se de um estudo observacional longitudinal, realizado na cidade de Maringá - PR, com 71 pacientes, incluídos no período de julho de 2004 a dezembro de 2005, avaliados antes e seis meses após a cirurgia. Foram estudados 42 mulheres e 29 homens, com idade variando de 18 a 66 anos (mediana de 36 anos) e índice de massa corpórea (IMC) variando de 37,1 a 56,2 kg/m2 (mediana de 41,9 kg/m2). Do total, 28 eram hipertensos. Não foram incluídos pacientes com diagnóstico de diabetes melito. Análise da variabilidade da freqüência cardíaca no domínio do tempo através de gravações de Holter 24 horas, teste de inclinação ortostática e dosagem de noradrenalina em urina de 24 horas foram realizadas nas duas fases do estudo. Também foram avaliados glicemia e insulina de jejum, perfil lipídico, proteína C-reativa de alta sensibilidade, fibrinogênio e qualidade de vida através do questionário SF-36. RESULTADOS: A redução média do peso, seis meses após a cirurgia, foi de 25,46% e da circunferência abdominal, de 20,4%. A freqüência sinusal se reduziu significativamente, expressa pelo aumento do intervalo NN médio (p<0,001). Os índices da variabilidade da freqüência cardíaca SDNN, SDANN, SDNN index, pNN50 e rMSSD apresentaram aumento significativo (p<0,001, p<0,001, p=0,002, p=0,001 e p=0,002, respectivamente). Os homens apresentaram maior elevação do SDNN e SDANN do que as mulheres (p=0,006 e p=0,007, respectivamente). A idade foi fator significativo para a evolução do SDNN index (p=0,015) e rMSSD (p=0,002), reduzindo-se o aumento com o avanço da idade. A redução da circunferência abdominal apresentou melhor correlação com o aumento da variabilidade da freqüência cardíaca que as reduções do peso e IMC. Nenhum paciente apresentou sintoma novo de intolerância ortostática após a cirurgia. A resposta vasovagal ao teste de inclinação não apresentou diferença significativa entre as duas fases do estudo. A resposta disautonômica foi encontrada em apenas dois casos, após a cirurgia, fato que não permitiu a avaliação deste tipo de resposta. Não houve nenhum caso de hipotensão ortostática sintomática. Houve redução do número de casos de hipotensão ortostática assintomática, com razão de chance para a ocorrência após a cirurgia, em relação ao pré-operatório, de 0,10 (p=0,030). Não houve diferença nos níveis de noradrenalina urinária entre o pré e o pós-operatório. Houve redução da glicemia e insulina de jejum, melhora do perfil lipídico e redução da proteína C-reativa de alta sensibilidade, sem modificação do fibrinogênio. A qualidade de vida apresentou melhora. CONCLUSÃO: A gastroplastia com derivação gastrojejunal modificou o padrão autonômico, aumentando a ação parassimpática sobre o nó sinusal, evidenciada pelo aumento da variabilidade da freqüência cardíaca. A mudança ocorreu sem piora clínica da tolerância ortostática e sem aumento da suscetibilidade à síncope vasovagal. / INTRODUCTION: Findings from literature associate obesity with increased sympathetic activity. Roux-en-Y gastric bypass, which promotes large and rapid weigh loss, can influence the autonomic cardiovascular activity. The aim of the present study was to evaluate the influence of surgery on the heart autonomic modulation, orthostatic tolerance and 24-hour urinary norepinephrine. METHODS: The study was a longitudinal observation carried out in Maringá - PR, embracing 71 patients, recruited from July, 2004 to December, 2005, evaluated before surgery and six months post-operatively. Forty two (42) women and 29 men were investigated, with age varying from 18 to 66 years old (median = 36 years old) and body mass index (BMI) varying from 37.1 to 56.2 kg/m2 (median = 41.9 kg/m2). Out of the total, 28 presented arterial hypertension. Patients diagnosed as diabetics were not included. The analysis of the time domain measures of heart rate variability, by using 24-hour Holter recordings, head-up tilt testing (HUT) and urinary 24-hour norepinephrine assay was performed during both phases of the study. Fasting plasma glucose and insulin, lipid profile, high sensitivity C-reactive protein, fibrinogen and quality of life were also evaluated by applying the SF-36 questionnaire, all before surgery and post-operatively. RESULTS: Six months after surgery, the average of weight loss was 25.46% and the waist circumference reduction was 20.4%. The mean of NN interval showed a significant increase (p<0,001), thus denoting a significant reduction of sinusal rate. The measures of heart rate variability, that is, SDNN, SDANN, SDNN index, pNN50 and rMSSD, showed significant increase (p<0.001, p<0.001, p=0.002 and p=0.002, respectively). Men presented greater increase of SDNN and SDANN than women (p=0,006 and p=0,007, respectively). Age was a significant factor for the evolution of SDNN index (p=0.015) and rMSSD (p=0.002) with a lower increase according to the aging process. The waist circumference reduction presented better correlation with heart rate variability increase than weight loss and BMI reduction. After surgery, no patient showed new symptom of orthostatic intolerance. The vasovagal response to HUT did not present a significant difference between both phases of the study. Dysautonomic response occurred just in two cases, after surgery, not allowing the evaluation of that kind of response. There was no case of symptomatic orthostatic hypotension. There was a significant reduction of asymptomatic orthostatic hypotension cases, with odds ratio of 0.10 (p=0.030) after surgery, in relation to the pre-operative phase. There was not a difference of urinary 24-hour norepinephrine in the period investigated. Fasting plasma glucose and insulin reduced while lipid profile improved and high sensitivity C-reactive protein reduced, without changing the fibrinogen. Quality of life improved. CONCLUSION: Gastric bypass changed the autonomic modulation, increasing the parasympathetic activity on sinus node, which was denoted by an increase in the heart rate variability. The change occurred without clinical worse in orthostatic tolerance and without increase in the susceptibility to vasovagal syncope.

INTRODUÇÃO: Informações da literatura associam a obesidade a maior atividade simpática. A gastroplastia com derivação gastrojejunal em Y de Roux, que leva a redução rápida e intensa do peso, pode influenciar o padrão autonômico cardiovascular. O objetivo deste estudo é avaliar os efeitos dessa cirurgia sobre a modulação autonômica do coração, tolerância ortostática e excreção urinária de noradrenalina. METODOS: Trata-se de um estudo observacional longitudinal, realizado na cidade de Maringá - PR, com 71 pacientes, incluídos no período de julho de 2004 a dezembro de 2005, avaliados antes e seis meses após a cirurgia. Foram estudados 42 mulheres e 29 homens, com idade variando de 18 a 66 anos (mediana de 36 anos) e índice de massa corpórea (IMC) variando de 37,1 a 56,2 kg/m2 (mediana de 41,9 kg/m2). Do total, 28 eram hipertensos. Não foram incluídos pacientes com diagnóstico de diabetes melito. Análise da variabilidade da freqüência cardíaca no domínio do tempo através de gravações de Holter 24 horas, teste de inclinação ortostática e dosagem de noradrenalina em urina de 24 horas foram realizadas nas duas fases do estudo. Também foram avaliados glicemia e insulina de jejum, perfil lipídico, proteína C-reativa de alta sensibilidade, fibrinogênio e qualidade de vida através do questionário SF-36. RESULTADOS: A redução média do peso, seis meses após a cirurgia, foi de 25,46% e da circunferência abdominal, de 20,4%. A freqüência sinusal se reduziu significativamente, expressa pelo aumento do intervalo NN médio (p<0,001). Os índices da variabilidade da freqüência cardíaca SDNN, SDANN, SDNN index, pNN50 e rMSSD apresentaram aumento significativo (p<0,001, p<0,001, p=0,002, p=0,001 e p=0,002, respectivamente). Os homens apresentaram maior elevação do SDNN e SDANN do que as mulheres (p=0,006 e p=0,007, respectivamente). A idade foi fator significativo para a evolução do SDNN index (p=0,015) e rMSSD (p=0,002), reduzindo-se o aumento com o avanço da idade. A redução da circunferência abdominal apresentou melhor correlação com o aumento da variabilidade da freqüência cardíaca que as reduções do peso e IMC. Nenhum paciente apresentou sintoma novo de intolerância ortostática após a cirurgia. A resposta vasovagal ao teste de inclinação não apresentou diferença significativa entre as duas fases do estudo. A resposta disautonômica foi encontrada em apenas dois casos, após a cirurgia, fato que não permitiu a avaliação deste tipo de resposta. Não houve nenhum caso de hipotensão ortostática sintomática. Houve redução do número de casos de hipotensão ortostática assintomática, com razão de chance para a ocorrência após a cirurgia, em relação ao pré-operatório, de 0,10 (p=0,030). Não houve diferença nos níveis de noradrenalina urinária entre o pré e o pós-operatório. Houve redução da glicemia e insulina de jejum, melhora do perfil lipídico e redução da proteína C-reativa de alta sensibilidade, sem modificação do fibrinogênio. A qualidade de vida apresentou melhora. CONCLUSÃO: A gastroplastia com derivação gastrojejunal modificou o padrão autonômico, aumentando a ação parassimpática sobre o nó sinusal, evidenciada pelo aumento da variabilidade da freqüência cardíaca. A mudança ocorreu sem piora clínica da tolerância ortostática e sem aumento da suscetibilidade à síncope vasovagal. / INTRODUCTION: Findings from literature associate obesity with increased sympathetic activity. Roux-en-Y gastric bypass, which promotes large and rapid weigh loss, can influence the autonomic cardiovascular activity. The aim of the present study was to evaluate the influence of surgery on the heart autonomic modulation, orthostatic tolerance and 24-hour urinary norepinephrine. METHODS: The study was a longitudinal observation carried out in Maringá - PR, embracing 71 patients, recruited from July, 2004 to December, 2005, evaluated before surgery and six months post-operatively. Forty two (42) women and 29 men were investigated, with age varying from 18 to 66 years old (median = 36 years old) and body mass index (BMI) varying from 37.1 to 56.2 kg/m2 (median = 41.9 kg/m2). Out of the total, 28 presented arterial hypertension. Patients diagnosed as diabetics were not included. The analysis of the time domain measures of heart rate variability, by using 24-hour Holter recordings, head-up tilt testing (HUT) and urinary 24-hour norepinephrine assay was performed during both phases of the study. Fasting plasma glucose and insulin, lipid profile, high sensitivity C-reactive protein, fibrinogen and quality of life were also evaluated by applying the SF-36 questionnaire, all before surgery and post-operatively. RESULTS: Six months after surgery, the average of weight loss was 25.46% and the waist circumference reduction was 20.4%. The mean of NN interval showed a significant increase (p<0,001), thus denoting a significant reduction of sinusal rate. The measures of heart rate variability, that is, SDNN, SDANN, SDNN index, pNN50 and rMSSD, showed significant increase (p<0.001, p<0.001, p=0.002 and p=0.002, respectively). Men presented greater increase of SDNN and SDANN than women (p=0,006 and p=0,007, respectively). Age was a significant factor for the evolution of SDNN index (p=0.015) and rMSSD (p=0.002) with a lower increase according to the aging process. The waist circumference reduction presented better correlation with heart rate variability increase than weight loss and BMI reduction. After surgery, no patient showed new symptom of orthostatic intolerance. The vasovagal response to HUT did not present a significant difference between both phases of the study. Dysautonomic response occurred just in two cases, after surgery, not allowing the evaluation of that kind of response. There was no case of symptomatic orthostatic hypotension. There was a significant reduction of asymptomatic orthostatic hypotension cases, with odds ratio of 0.10 (p=0.030) after surgery, in relation to the pre-operative phase. There was not a difference of urinary 24-hour norepinephrine in the period investigated. Fasting plasma glucose and insulin reduced while lipid profile improved and high sensitivity C-reactive protein reduced, without changing the fibrinogen. Quality of life improved. CONCLUSION: Gastric bypass changed the autonomic modulation, increasing the parasympathetic activity on sinus node, which was denoted by an increase in the heart rate variability. The change occurred without clinical worse in orthostatic tolerance and without increase in the susceptibility to vasovagal syncope.

“Dysautonomia” or a dysfunction of the autonomic nervous system, affects approximately 70 million children and adults worldwide. Despite this, a small fraction of studies focus on the experiences of children and teenagers' living with conditions related to dysautonomia. The aim of this study is thus to explore the experiences and perspective of teenagers living with dysautonomia, by focusing on how they describe their lives in relation to being chronically ill and how they view the relationships among themselves, their doctors and their peers. The study entails a social constructionist and an interpretative phenomenological approach, which focuses on the lived experiences of the teenagers. To collect the data, an email questionnaire1 was conducted with 16 teenagers from different parts of the world. The data was analyzed with the help of a thematic analysis. Seven themes were identified under my areas of interest; a regular day, relationships with peers and relationships with doctors. The results indicated that dysautonomia, similar to other chronic illnesses, was reducing life quality. The results also indicated that most days were spent trying to distract themselves from their illnesses. The participants described feelings related to uncertainty, fear, loneliness and grief. Difficulties remaining socially active and maintaining friendships were described by some of the participants. Relationships with peers were described as both supportive and unsupportive and were often described in terms of healthy and sick peer groups. The doctor-patient relationship was described in terms of good and bad qualities. Although all participants described feeling dismissed, belittled and accused of making their symptoms and illnesses up in their heads, some also described the opposite - the good and respectful listener, who valued the autonomy of the participants.