Dissertationen zum Thema „Aging cardiac“
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Inuzuka, Yasutaka. „Suppression of phosphoinositide 3-kinase prevents cardiac aging in mice“. Kyoto University, 2009. http://hdl.handle.net/2433/126462.
Der volle Inhalt der QuelleHaynes, Premi. „TRANSMURAL HETEROGENEITY OF CELLULAR LEVEL CARDIAC CONTRACTILE PROPERTIES IN AGING AND HEART FAILURE“. UKnowledge, 2014. http://uknowledge.uky.edu/physiology_etds/16.
Der volle Inhalt der QuelleYang, Bo, und 杨波. „Role of lipocalin-2 in cardiac dysfunction associated with aging and dietary obesity“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B47869641.
Der volle Inhalt der Quellepublished_or_final_version
Pharmacology and Pharmacy
Doctoral
Doctor of Philosophy
Ueno, Linda Massako. „Effects of aging and regular exercise upon baroreflex sensitivity and cardiac autonomic activities“. Kyoto University, 2003. http://hdl.handle.net/2433/148937.
Der volle Inhalt der Quelle0048
新制・課程博士
博士(人間・環境学)
甲第10300号
人博第187号
14||151(吉田南総合図書館)
新制||人||46(附属図書館)
UT51-2003-H721
京都大学大学院人間・環境学研究科文化・地域環境学専攻
(主査)教授 森谷 敏夫, 教授 中村 榮太郎, 教授 津田 謹輔
学位規則第4条第1項該当
Amano, Masari. „Effects of exercise training, aging, gender and mental stress upon cardiac autonomic nervous function“. Kyoto University, 2003. http://hdl.handle.net/2433/148936.
Der volle Inhalt der Quelle0048
新制・課程博士
博士(人間・環境学)
甲第10299号
人博第186号
14||150(吉田南総合図書館)
新制||人||45(附属図書館)
UT51-2003-H720
京都大学大学院人間・環境学研究科文化・地域環境学専攻
(主査)教授 森谷 敏夫, 教授 津田 謹輔, 教授 田口 貞善
学位規則第4条第1項該当
Ramsey, Michael Wiechmann. „Effects of head-up tilt on mean arterial pressure, heart rate, and regional cardiac output distribution in aging rats“. Texas A&M University, 2005. http://hdl.handle.net/1969.1/3094.
Der volle Inhalt der QuelleAnstine, Lindsey J. „Valve cell dynamics in developing, mature, and aging heart valves“. The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1478692972995079.
Der volle Inhalt der QuelleLODRINI, ALESSANDRA MARIA. „Cellular senescence and failure in human and animal cardiac myocytes“. Doctoral thesis, Università degli Studi di Milano-Bicocca, 2021. http://hdl.handle.net/10281/301783.
Der volle Inhalt der QuelleDuring my PhD I was involved mainly in two research projects aimed to study myocardial dysfunction induced by aging or chemotherapy. The first study aimed to reproduce and characterize mechanisms involved in aging using cardiomyocytes (CMs) from human induced pluripotent stem cells (hiPSCs), and to test cardioprotective therapies, like cardiac progenitor cell (CPC)-derived exosomes (Exo). Aging of the heart involves adverse remodeling in CMs which results in heart failure with incidence that increases with age. Interestingly, till now we lacked a human model of cardiac aging. We reprogrammed CPCs into hiPSCs and subsequently differentiated in hiPSC-derived CMs. A senescence-like phenotype (SenCMs) was induced by short exposure (3 hours) to doxorubicin (Dox) at sub-lethal concentration (0.2 µM). 24h following DOX treatment, SenCMs were exposed to Exo (~2·103 particles/cell) collected from culture media of CPCs by ultracentrifugation. Dox treatment induced senescence, as confirmed by activation of p21 and increased SA-β-gal positivity compared to control CMs (cCMs). Biochemical analysis revealed presence of oxidative stress and a depolarized mitochondrial membrane potential due to the treatment, which resulted in decreased ATP production by mitochondria. SenCMs also showed impaired calcium handling and prolonged QTc vs. cCMs due to upregulation of INaL. These effects were mitigated by exposure to Exo. Overall, SenCMs recapitulate the phenotype of aged CMs in terms of senescence markers and electrical and metabolic properties. Additionally, exposure to CPC-derived Exo limited age-related cardiac anomalies. The second study aimed to study the cardiac dysfunction dependent on the combined administration of Dox and trastuzumab (Trz) through evaluation of cardiac performance, T-tubule organization, and electrophysiological changes in cardiac myocytes from an in-vivo rat model. Combined treatment with Dox and Trz in patients with HER2-positive cancer is limited by cardiotoxicity, as manifested by contractile dysfunction and arrhythmia. The respective roles of the two agents in the cardiotoxicity of the combined therapy are incompletely understood. Adult rats received 6 doses of either Dox or Trz, or the two agents sequentially. Dox-mediated left ventricular (LV) dysfunction was aggravated by Trz administration. Dox treatment, but not Trz, induced T-tubule disarray. Moreover, Dox, but not Trz monotherapy, induced prolonged action potential duration (APD), increased incidence of delayed afterdepolarizations (DADs) and beat-to-beat variability of repolarization (BVR), and slower Ca2+ transient decay. Although APD, DADs, BVR and Ca2+ transient decay recovered over time after the cessation of Dox treatment, subsequent Trz administration exacerbated these abnormalities. Trz, but not Dox, reduced Ca2+ transient amplitude and SR Ca2+ content. Both agents increased Ca2+ waves and downregulated SERCA. Finally, Dox increased resting Ca2+ waves, Ca2+ spark frequency, spark-mediated sarcoplasmic reticulum (SR) leak, and long-lasting Ca2+ release events (so-called Ca2+ “embers”). These results suggest that Dox, but not Trz, may cause T-tubule disarray in cardiac myocytes in vivo while also inducing overall larger changes in electrical parameters and intracellular Ca2+ handling. While Dox-induced changes in electrical parameters are reversible, subsequent Trz administration prevents their recovery. These findings illustrate the specific roles of Dox and Trz, and their interactions in cardiotoxicity and arrhythmogenicity.
ZENI, FILIPPO. „Circulating levels of soluble Receptor for Advanced Glycation End-products (sRAGE) decrease with aging and may predict age-related cardiac remodeling“. Doctoral thesis, Università degli Studi di Milano-Bicocca, 2017. http://hdl.handle.net/10281/170797.
Der volle Inhalt der QuelleBackground: Aging is an unavoidable risk factor in later life that can influence the onset and progression of many diseases. In fact, the high incidence of cardiovascular diseases in the elderly is mainly attributable to cardiac remodelling associated to physiological intrinsic aging. RAGE is a multi-ligand receptor involved in many age-related disorders. Its soluble isoform (sRAGE) acts as a decoy receptor being able to block the activation of the membrane-bound receptor, and its circulation levels have been found altered in several chronic and acute pathologies. The role of RAGE isoforms in aging and, in particular, cardiac senescence has never been investigated. Moreover, the finding of reliable biomarkers able to assess individual health status of subjects has important applications in prevention, diagnosis, and disease management. In this context, the aim of this study was to ascertain whether sRAGE is a biomarker of aging and age-related cardiac remodelling, and evaluate the contribution of RAGE isoforms to cardiac aging. Results: Serum of male and female from 20 to 92 years old healthy subjects was collected and sRAGE levels were evaluated by ELISA. We found a significant decrease of circulating sRAGE in males while only a trend in females. Accordingly, we observed a strong correlation of sRAGE with chronological age in male but not in female subjects. Male and female mice at different age (2.5-12-22-months, Young, Middle Age (MA) and Old, respectively) undergone 2D-echocardiography to determine the left ventricle (LV) dimensions and function during aging. Serum sRAGE similarly declines from the Young to the MA group in both sexes, and inversely correlate with LV dimensions and function, preferentially in males. No detectable amount of RAGE protein was found in LV at all ages. Rage-/- mice displayed a significant increase of LV volumes and diameters in diastole and systole, and a concomitant decrease in ejection fraction (EF) and fractional shortening (FS), compared to age-matched wt animals during aging with the strongest differences present between the MA groups. Moreover, MA Rage-/- mice exhibited higher deposition of collagen and expression of heart failure marker genes (BNP and Ankrd1) in respect to the wt counterpart. Conversely, no differences in cardiomyocytes size were observed at any age between the two genotypes. Finally, microarray functional annotation analysis based on the interaction between age-genotype revealed that the chronic lack of RAGE affected the expression of genes associated to contractile fibre function, antigen presenting process and adaptive immunity, insulin pathway, cell death and apoptosis. We also found a correlation between LV volumes and diameters in diastole and systole and differentially expressed genes involved in several processes like muscle contraction, fibrosis, wound healing and regulation of apoptosis. Conclusions: Our results indicate that sRAGE is a serum biomarker of healthy aging and age-related cardiac remodeling, preferentially in males. The absence of RAGE in mice exacerbates adverse cardiac remodeling with age. We propose that, among RAGE isoforms, sRAGE may play a pivotal role in cardiac senescence.
Sheikh, Hajer Nisar. „Tropomyosin Phosphorylation in Cardiac Health and Disease“. University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1242913472.
Der volle Inhalt der QuelleFurlan, Ana Kaline Pereira Damasceno. „Diferenciação dos perfis hemodinâmicos e autonômicos cardiovasculares em mulheres jovens e de meia idade pós-menopausa“. Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/17/17152/tde-05012017-125234/.
Der volle Inhalt der QuelleThe stage of adulthood between 35 and 60, also known as middle-aged, covers the period in which the main biological systems have important functional decline. In women, specifically, it is the stage marked by climacteric whose main event the occurrence of menopause. This physiological event of hormonal and reproductive importance is associated in many women to the significant increase in the prevalence of cardiovascular disease, often associated and preceded by losses in cardiovascular autonomic function. In this sense, the evaluation of cardiac autonomic functionality is very important as practice for cardiovascular risk stratification. In fact, the analysis of heart rate variability (HRV) is widely used, however the methodology follows a standard protocol that does not take into account important physiological situations, such as the reorganization of cardiac autonomic modulation after exercise-induced stress. Additionally, the literature has opted for linear tools instead of linear no evaluation of HRV. In this case, the purpose of this study was to evaluate and compare the cardiac autonomic function in young women (GJ: 21 to 30 years) and half postmenopausal age (GMI: 45-60 years) through the linear analysis (spectral analysis ) and non-linear (symbolic analysis) of heart rate variability at three different times (at rest in the supine position during the tilt test and during the recovery period after submaximal cardiopulmonary test). The GMI showed lower values of peak VO2 (24 ± 1.0 vs 39 ± 1.3 ml.kg. min-1) basal heart rate (71 ± 2 vs 81 ± 2 bpm) and higher mean arterial pressure (91 ± 2 vs 81 ± 1 mm Hg) compared to GJ. Also showed higher sympathetic modulation and lower vagal modulation of HF in the supine position, however only evidenced by linear analysis. During the tilt test responses GMI were less prominent compared to GJ. In this case, the linear and nonlinear tools showed similar results. Finally, the analysis of HRV after submaximal cardiopulmonary test showed that the GMI recovered faster autonomic modulation, shown in both analyzes, linear and non-linear. In conclusion, the evaluation of cardiac autonomic modulation showed that resting young women have a predominance of vagal autonomic component, while women half postmenopausal age present a sympathetic predominance. In turn, the tilt test showed that the autonomic response of young women is more intense, but the autonomic reorganization after exercise, the middle-aged women have faster the reestablishment of vagal modulation. The reasons are unknown, but may be due to the reduction in ovarian hormones, as well as the aging process by establishing less complex physiological mechanisms.
Wilson, Amber Diane. „Determining the Effects of Aging on Murine Bone-Marrow Derived Mesenchymal Stem Cell Cardiac and Angiogenic Plasticity Potential“. Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/641.
Der volle Inhalt der QuelleKoser, Franziska [Verfasser], und Markus [Akademischer Betreuer] Hecker. „Role of the ubiquitin-proteasome system in the pathogenesis of cardiac hypertrophy and aging / Franziska Koser ; Betreuer: Markus Hecker“. Heidelberg : Universitätsbibliothek Heidelberg, 2015. http://d-nb.info/1180500067/34.
Der volle Inhalt der QuellePIANTONI, CHIARA. „ELECTROPHYSIOLOGICAL CHARACTERIZATION OF THE CARDIAC PACEMAKER ACTIVITY DURING AGING AND IN THE PRESENCE OF THE TRADITIONAL CHINESE MEDICINE DRUG TMYX“. Doctoral thesis, Università degli Studi di Milano, 2018. http://hdl.handle.net/2434/546167.
Der volle Inhalt der QuelleMode of action of the Traditional Chinese Medicine drug TMYX on pacemaker activity in freely-moving mice and in isolated SAN cells. The identification of novel pharmacological agents able to selectively reduce sinus rate has a strong interest in the clinic because of their potential use in the treatment of ischemic heart disease such as angina pectoris. Despite longstanding and intense investigation, at present there is only one such agent (Ivabradine) that has reached therapeutic application, since all other compounds tested had additional undesired side-effects 11,12 . Our laboratory has started few years ago a collaboration with the University of Tianjin (China) to investigate the efficacy of the cardioactive compound Tongmai Yangxin (TMYX) which is currently used in the Traditional Chinese Medicine as a cardiac regulator 13 . Electrophysiological experiments performed on rabbit SA node cells have shown a dose-dependent slowing effect of TMYX on pacemaking action potential rate. The investigation of the effects of TMYX on the I f current, the major contributor of diastolic depolarization phase, has revealed that at physiological potential the drug exerts a bradycardic action, thus confirming the effect on the spontaneous automaticity observed in SA node cells. During my experimental work, I continued the characterization of the mechanism of action of this Traditional Chinese Medicine drug, working on two parallel aspects: 1) the evaluation of the systemic effect of TMYX and 2) the identification of the molecular mechanisms of the drug. 1) The systemic effect of TMYX was evaluated in freely-moving mice implanted with ECG transmitters. When TMYX was delivered during pharmacological blockade of either sympathetic alone or in combination with parasympathetic block, a deep bradycardia was observed, confirming the in-vitro bradycardic effect. However, quite surprisingly, when the drug was delivered (i.p. injection) during basal heart rate condition, the experiments show an increment of heart rate. 2) Our previous in-vitro experiments had revealed that TMYX acts directly on pacemaker SAN cells and blocks the pacemaker current. We therefore started a series of experiments aiming at the identification of the site of action of TMYX. Our experiments suggest that TMYX shares the modulatory pathway of ACh, but they also exclude that TMYX can bind to the M2 receptor because atropine does not alter the action of TMYX. We then performed inside-out experiments and demonstrated that TMYX does not have any action on the channel when cAMP is either completely absent or it is present at saturating high levels, while TMYX decreases the pacemaker current when cAMP is present at non-saturating levels. Taken together our results demonstrate the presence of at least two molecules that exert different actions: one is a bradycardic agent, whose effect is observed in isolated SAN cells and in the in-vivo model, and the other one is a systemic tachycardic agent, whose effect is observed in the absence of autonomic block. The bradycardic agent appears to behave as an antagonist of the sympathetic stimulation of heart rate. The antagonist action on the sympathetic activity is a key pharmacologic mechanism used by the so-called β-blocker drugs. These drugs are largely used to treat a large number of cardiac diseases including Coronary Artery Disease (CAD) and Heart Failure (HF). However, the often-undesired side effect of β-blockers is a decreased strength of contraction (inotropism) of the heart. According to our data it appears that the active molecule in the TMYX acts directly on the pacemaker channel by antagonizing the stimulating action of cAMP, while β-blockers slow heart rate by decreasing the cAMP levels. This direct antagonistic effect, rather than a block of cAMP production should decrease the heart rate leaving unaltered the strength of contraction. We thus intend to identify and isolate the specific tachycardic/bradycardic molecules since they could have a strong impact in the clinical use.
Leone, R. „ANALISI PROTEOMICA DEL MUSCOLO CARDIACO DI RATTO IN CORSO D'INVECCHIAMENTO“. Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/231150.
Der volle Inhalt der QuelleXu, Kui. „The Central Nervous System Aspects of Cardiac Arrest and Resuscitation in a Rat Model of Global Ischemia“. Case Western Reserve University School of Graduate Studies / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1270689501.
Der volle Inhalt der QuelleMonteiro, Clara Italiano. „Avaliação da fase de recuperação após exercício resistido em idosos e jovens : análise da modulação autonômica cardíaca“. Universidade Federal de São Carlos, 2017. https://repositorio.ufscar.br/handle/ufscar/8822.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Aging is a complex, dynamic and progressive process characterized by morphological, functional, biochemical, psychological and social age-related changes. These changes occur progressively and lead the individual to gradual reduction of their adaptability and performance skills, making them more vulnerable to intrinsic and extrinsic factors. Resistance training is recommended for elderly people as a promising intervention to prevent or reverse, at least partially, the effects caused by this process. However, the number of studies that address cardiovascular variables behavioral patterns during the recovery period after resistance exercise in the elderly is still limited, despite the potentially useful information that might arise from this observation. In this context, the aim of the present proposal is to analyze the response of the response of heart rate variability (HRV) to resistance exercise during the recovery period (6 minutes) in elderly and young subjects. Volunteers will undergo three visits: 1. ramp type exercise test on a cycle ergometer (clinic avaluation); 2. one maximum repetition (MR) test and 3. A test at an intensity of 70% and 90% of 1RM, on the Leg Press 45º device. The records of the heart frequency (HR) was collected throughout the tests. Our hypothesis is that cardiovascular adjustments, investigated through HRV analysis, will be attenuated in the elderly when compared to young subjects. The results were compared using two-way repeated-measures ANOVA. A significant difference was found between elderly and young during the recovery phase for Mean RR, LF n.u., DFA1 and DFA2. Our findings show that the elderly present higher sympathetic modulation during RE recovery when compared to young subjects, which might be indicative of an attenuated response to exercise in this population.
O envelhecimento é um processo complexo, dinâmico e progressivo, caracterizado por alterações morfológicas, funcionais, bioquímicas, psicológicas e sociais. Tais alterações ocorrem de maneira progressiva e levam o indivíduo à diminuição gradual de sua capacidade de adaptação e desempenho, tornando-o mais vulnerável às agressões intrínsecas e extrínsecas. O treinamento resistido é recomendado para os indivíduos idosos como uma promissora intervenção para prevenir ou reverter, pelo menos parcialmente, as perdas causadas por este processo. No entanto, ainda são limitados os estudos que investigaram o comportamento das variáveis cardiovasculares no período de recuperação pós-esforço em exercício resistido (ER) em idosos, apesar das informações potencialmente úteis que poderiam advir de tal investigação. Neste contexto, a presente proposta terá como objetivo analisar a resposta da variabilidade da frequência cardíaca (VFC) no período de recuperação pós-exercício resistido em indivíduos idosos e jovens. Foram realizadas 3 visitas para realização dos seguintes testes: 1. teste ergométrico do tipo rampa em cicloergômetro (para avaliação clínica); 2. teste de uma repetição máxima (RM) e 3. teste em 70% e 90% do RM no equipamento Leg Press 45º. Os registros dos sinais de frequência cardíaca (FC) foram realizados durante o repouso e no período de recuperação (6 minutos) dos testes de 70% e 90% de 1RM. A hipótese deste estudo é a de que os ajustes cardiovasculares avaliados pela análise da VFC estarão atenuados nos indivíduos idosos quando comparados aos indivíduos jovens. Foi utilizada para análise dos dados ANOVA de medidas repetidas de duas vias. Foram encontradas diferenças significativas entre idosos e jovens durante a fase de recuperação nas seguintes variáveis: média RR, BF u.n., DFA1 e DFA2. Podemos concluir que os idosos apresentam uma modulação simpática com valores mais altos durante a recuperação do que os jovens, podendo ser indicativo de uma resposta atenuada ao exercício nessa população.
CNPq: 450500/2016-0
CNPq: 117515/2014-0
CNPq: 486365/2013-1
Long, Meghan. „Comparison of High Intensity Interval Training Versus Moderate Intensity Continuous Training in a Phase II Cardiac Rehabilitation Program“. Bowling Green State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1498769361795025.
Der volle Inhalt der QuelleSimões, Rodrigo Polaquini. „Análise do controle autonômico cardíaco e do metabolismo muscular durante o exercício descontínuo dinâmico e resistido em homens jovens e idosos“. Universidade Federal de São Carlos, 2012. https://repositorio.ufscar.br/handle/ufscar/5146.
Der volle Inhalt der QuelleUniversidade Federal de Minas Gerais
The thesis consisted of three studies described below. Study I, which aimed to investigate the effect of aging on kinetic responses of heart rate (HR) and oxygen consumption (VO2) during rest-exercise (ontransient) and exercise-recovery transitions (off-transient), and to investigate the influence of exercise intensity (mild and moderate) on the kinetic parameters of these variables. 28 apparently healthy men were evaluated, and 14 constituted the young group (YG) and 14 the elderly group (EG). The evaluation consisted of applying an incremental exercise testing of ramp protocol on cycle-ergometer (IET-R) to determine the maximum power (MP) and discontinuous exercise test on a cycle ergometer (DET-C), which started with an initial power load of 10% of MP with subsequent increase of 10% until exhaustion. Were recorded ventilatory and metabolic variables, the HR and blood lactate at rest and during exercise. The lactate threshold (LT) was closed between the groups (approximately 30% of MP). The EG showed higher values of the kinetic responses, both on and off transitions of HR and VO2 (p<0.05), and the values were higher in moderate compared to mild in YG (p<0.05). We conclude that the elderly have slower kinetic responses of HR and VO2 in relation to young and that at moderate intensity; the kinetic responses were slower in relation to mild intensity in young. Following, the study II aimed to investigate the behavior of the heart rate variability (HRV) responses during a discontinuous resistance exercise (RE) protocol and check whether they agree with the blood lactate responses in the determination of anaerobic threshold (AT) in apparently healthy young and elderly. For this proposal, in the same volunteers in the study I, was applied the test of one repetition maximum (1RM) on the leg press 45º and the discontinuous exercise test on the leg press 45 (DET-L), initiated in 10% of 1RM subsequent increments of 10% until exhaustion, and the HR and blood lactate were obtained at rest and during exercise. The AT was determined at approximately 30% of 1RM in both groups and both methods of analysis (blood lactate and HRV), the HRV index decreased with increasing load and stabilized from the load corresponding to AT in both groups, additionally the blood lactate remained practically stable until the load of AT, and increased significantly after this intensity. The EG had lower HRV values in lower loads of AT, and lower values of HR and blood lactate in loads above of AT in relation to the YG. We conclude that the HRV responses to determine the AT are according to blood lactate, and that the increase in load during the discontinuous RE promoted gradual vagal withdrawal followed by sympathetic activation in both young and the elderly, however, these responses are attenuated with the aging process. Finally, the study III, aimed to determine the AT during discontinuous dynamic and resistance exercise protocol by analyzing blood lactate and HRV in healthy older adults, comparing the cardiovascular, metabolic and autonomic variables between these two exercise modalities. We evaluated the elderly group of individuals during the tests: IET-R, DET-C, 1RM and DET-L. The AT within about 30% of maximum intensity in both the DET-C and DET-L by both methods (blood lactate and HRV). There were no differences in HRV variables between the modalities of exercise and a significant increase in systolic blood pressure and blood lactate after AT load in the DET-L. We conclude that HRV was effective in determining the AT and that the parasympathetic modulation responses were similar between dynamic and resistance exercise.
A tese constou de 3 estudos descritos a seguir. Estudo I, que teve como objetivo investigar o efeito do envelhecimento nas respostas cinéticas da frequência cardíaca (FC) e do consumo de oxigênio (VO2) durante as transições repouso-exercício (fase-on) e exercício-recuperação (fase-off), além de verificar a influência da intensidade do exercício (leve e moderada) sobre os parâmetros cinéticos destas variáveis. 28 homens aparentemente saudáveis foram avaliados, sendo que 14 constituíram o grupo de jovens (GJ) e 14 o grupo de idosos (GI). A avaliação foi constituída da aplicação de um teste de esforço incremental do tipo rampa (TEI-R) em cicloergômetro para determinar a potência máxima (PM) e teste de exercício descontínuo no cicloergômetro (TED-C), sendo este último iniciado com carga inicial de 10% da PM com aumentos subsequentes de 10% até a exaustão. Foram registradas as variáveis ventilatórias e metabólicas, a FC e a lactacidemia em repouso e durante o esforço. O limiar de lactato (LL) foi verificado em cargas relativas similares entre os grupos (aproximadamente em 30% da PM). O GI apresentou maiores valores das respostas cinéticas, tanto na transição on como off da FC e do VO2 (p<0,05), e os valores foram maiores na intensidade moderada em comparação à leve no GJ (p<0,05). Concluímos que os idosos tem respostas cinéticas mais lentas da FC e do VO2 em relação aos jovens e que em intensidade moderada, as respostas cinéticas foram mais lentas em relação à intensidade leve nos jovens. Na sequência, o estudo II objetivou investigar o comportamento das respostas da variabilidade da frequência cardíaca (VFC) durante um protocolo de exercício resistido (ER) descontínuo e verificar se estas são concordantes com as respostas de lactacidemia na determinação do limiar anaeróbio (LA) em jovens e idosos aparentemente saudáveis. Para tal proposta, nos mesmos voluntários do estudo I, foi aplicado o teste de uma repetição máxima (1RM) no leg press 45º e o teste de exercício descontínuo no leg press 45º (TED-L), iniciado em 10% de 1RM com incrementos subsequentes de 10% até a exaustão, sendo a FC e a lactacidemia obtidas no repouso e no exercício. O LA foi determinado em aproximadamente 30% da 1RM em ambos os grupos e em ambos os métodos de análise (lactacidemia e VFC), os índices da VFC diminuíram com aumento da carga e se estabilizaram a partir da carga do LA em ambos os grupos, adicionalmente, a lactacidemia manteve-se praticamente estável até a carga do LA, aumentando significativamente após esta intensidade. O GI apresentou valores reduzidos da VFC nas cargas inferiores ao LA, e valores reduzidos de FC e lactacidemia nas cargas acima do LA, em relação ao GJ. Concluímos que as respostas de VFC para determinar o LA estão de acordo com a lactacidemia, e que o aumento das cargas durante o ER descontínuo, promoveu gradual retirada vagal, seguida pela ativação simpática, tanto nos jovens como nos idosos, no entanto, estas respostas são atenuadas com o processo de envelhecimento. Finalmente o estudo III, teve como objetivo determinar o LA em protocolo de exercício descontínuo dinâmico e resistido por meio da análise da lactacidemia e da VFC em idosos saudáveis, comparando as variáveis cardiovasculares, metabólicas e autonômicas entre estas duas modalidades. Foram avaliados os indivíduos do grupo idoso durante os testes: TEI-R, TED-C, 1RM e TED-L. O LA ocorreu em aproximadamente 30% da intensidade máxima tanto no TED-C como no TED-L, por ambos os métodos (lactacidemia e VFC). Não houve diferenças em relação às variáveis da VFC entre as modalidades de exercício e houve aumento significativo da pressão arterial sistólica e lactacidemia após a carga do LA no TED-L. Concluímos que a VFC foi eficaz na determinação do LA e que as respostas da modulação parassimpática foram semelhantes entre o exercício dinâmico e resistido.
Lambert, Delphine. „Influence d’un régime riche en graisses sur un modèle de vieillissement « accéléré » : étude de la fonction et de la morphologie cardiaque, la fonction artérielle, le métabolisme et l’inflammation“. Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0266/document.
Der volle Inhalt der QuelleObesity and being overweight have been described as a global pandemic. Both obesity and aging will lead to cardiovascular complications. In addition, it has been highlighted that obesity promotes premature cardiac aging in young adults. The hypothesis of this work is that a high fat diet begun before adulthood, pursued over a long period of time, could lead to “accelerated” cardiovascular and metabolic aging. We have demonstrated, in an aging mouse model, that an early high fat diet leads to metabolic disorders and to an increase in fat mass and a deterioration in metabolism of white adipose tissue. These disorders are associated with alterations in cardiac morphology and function, despite an absence of changes in blood pressure and heart rate. Ageing, in obese mice, leads to ventricular remodeling accompanied by systolic dysfunction. In cardiac tissue, aging and early diet lead to an increased expression of fibrosis genes confirming the hypertrophic phenotype. Aging associated with an early high fat diet led also to an up-regulation of GDF11. GDF11 may then be considered as a marker of accelerated cardiac aging. These results may suggest therapeutic or preventive pathways, where inhibition of GDF11 improves prognosis and survival in obese subjects with cardiovascular disease. The study of this model has allowed us to demonstrate that a high fat diet leads to accelerated aging at the level of the heart
Robinson, Emma. „Control of cardiac remodelling during ageing and disease by epigenetic modifications and modifiers“. Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/275733.
Der volle Inhalt der QuelleMarron, Kevin. „Human cardiac innervation : regional distribution, morphology and changes with ageing“. Thesis, Imperial College London, 1996. http://hdl.handle.net/10044/1/11262.
Der volle Inhalt der QuelleDurollet, Marie. „Régulation de la fonction cardio-respiratoire au cours du cycle de vie de Nothobranchius furzeri : rôle de la température“. Thesis, La Rochelle, 2015. http://www.theses.fr/2015LAROS037/document.
Der volle Inhalt der QuelleCardio-respiratory system plays a key role in an organism by delivering oxygen and nutrients towards the cells. Exploring its age-dependant changes is therefore a corner stone for assessing the organism capacity to meet its energetic needs along its life cycle, and for the understanding of mechanisms involved in the mortality due to aging process. This study was realized in a vertebrate with an extremely short lifespan (~6 months), the fish Nothobranchius furzeri. Temperature is an external factor that regulates longevity. Here, fish were acclimatized at two temperatures, 26 °C considered as the optimal temperature for this species, and 22 °C. Biological responses of fish were evaluated at individual level through the assessment of aerobic metabolic scope (AS), growth, reproduction, locomotion and digestion, which are considered to be relevant indirect measurement of fitness. Furthermore, mechanisms involved in the cardiac function regulation were explored through a morpho-functional study of cardiomyocytes. Along the individual life cycle, two phases were emphasized: 1) the first corresponds to AS elevation from the juvenile to the adult stages, following by 2) a second phase reflecting the entrance in the senescent stage, characterized by the decline in AS, cardiac performances and in activity level. A temperature reduction increases the individual longevity and slows-down deleterious effect of aging on both AS and cardiac function. This study will contribute to provide a global vision of senescent effects on cardio-respiratory system, and a better understanding of the mechanisms involved in temperature-dependent increase in longevity
Gueda, Moussa Moussa. „Biomarqueurs quantitatifs de la déformation myocardique multi-chambres et multidirectionnelle en imagerie IRM dynamique“. Electronic Thesis or Diss., Sorbonne université, 2024. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2024SORUS104.pdf.
Der volle Inhalt der QuelleMyocardial strain quantified from echocardiography or from cine magnetic resonance imaging (MRI) using conventional image processing (speckle or feature tracking), is a powerful markerof myocardial damage, as it is modified earlier in the course of the disease as compared to global markers commonly used in clinical routine. Despite such performances, its systematic use in routine remains hampered by the complexity and the time-consuming nature of the manual initialization of the myocardial borders. Besides, clinical software is most often specific to the left ventricle, omitting the other chambers which are also targets of diseases but havinga much more complex geometry. In such a context, the main objectives of this thesis are: 1) to evaluate myocardial deformation through MRI feature tracking in all cardiac chambers while studying the effects of age on the estimated indices, 2) to take advantage of feature tracking derived contours in order to design new quantitative biomarkers of mechano-functional coupling between the atria and the ventricles in healthy aging, 3) to evaluate effect of data from different centers and manufacturers on these measurements and on strain measurements derived by feature tracking from cine MRI
Clements, Richard Edward. „The effects of ageing, endurance exercise and heart failure on cardiac power output“. Thesis, Liverpool John Moores University, 2005. http://researchonline.ljmu.ac.uk/5783/.
Der volle Inhalt der QuelleSharp, Lisa Joanne. „The effects of ageing and endurance-training on cardiac power output in healthy women“. Thesis, Liverpool John Moores University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431275.
Der volle Inhalt der QuelleWoods, Paul Robert. „The effects of ageing, exercise training and heart failure on cardiac function in men“. Thesis, Liverpool John Moores University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446332.
Der volle Inhalt der QuelleStephenson, Claire Elizabeth. „The impact of ageing and exercise training on cardiac structure and function in healthy females“. Thesis, Liverpool John Moores University, 2005. http://researchonline.ljmu.ac.uk/5796/.
Der volle Inhalt der QuelleHerraiz, Martínez Adela. „Effects of ageing and genetic risk variants at 4q25 on the calcium homeostasis in cardiac myocytes“. Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/401751.
Der volle Inhalt der QuelleAntecedentes El envejecimiento es un factor de riesgo que favorece enfermedades cardiovasculares comunes como la fibrilación auricular (FA) o la insuficiencia cardíaca (IC), que a la vez se asocian a cambios patológicos en la homeostasis intracelular de calcio. Sin embargo, no se conocen los efectos que el envejecimiento puede tener sobre los mecanismos de la homeostasis del calcio en cardiomiocitos auriculares humanos. Por otro lado, se han descrito variantes de riesgo genéticas asociadas a la FA en la región cromosómica 4q25, próximas al factor de transcripción Pitx2 que tiene un papel importante en el desarrollo cardíaco embrionario. En el corazón adulto Pitx2 se ha asociado a predisposición a arritmias auriculares, pero la relación que existe entre los variantes de 4q25 y la función de Pitx2 es controvertida. Además, se desconocen los efectos que los variantes de riesgo 4q25 tienen sobre la homeostasis del calcio. Por ello, en esta tesis se han investigado los mecanismos que pueden subyacer a los dos factores de riesgo envejecimiento y variantes de riesgo en 4q25. Hipótesis El envejecimiento y las variantes de riesgo en 4q25 producen alteraciones en la homeostasis del calcio intracelular en miocitos auriculares, que por sí solas o en combinación contribuyen a aumentar la propensión a la fibrilación auricular. Objetivos * Analizar los efectos del envejecimiento en los mecanismos que regulan la homeostasis del calcio en miocitos auriculares humanos. * Utilizar modelos murinos transgénicos de envejecimiento para identificar los mecanismos moleculares que subyacen a los cambios en la homeostasis del calcio debido al envejecimiento. * Investigar cómo las variantes de riesgo en el cromosoma 4q25 asociadas con un mayor riesgo de FA, afectan a las características electrofisiológicas de los miocitos auriculares humanos e identificar los mecanismos moleculares subyacentes. * Investigar como la edad modula los efectos de las variantes de riesgo en 4q25 en miocitos auriculares humanos. Métodos Los experimentos se llevaron a cabo en células auriculares o ventriculares aisladas de humano o de los distintos modelos murinos. Mediante las técnicas de patch-clamp y microscopía confocal se obtuvieron los datos electrofisiológicos. Las técnicas de RT-PCR y western blot se usaron para determinar los niveles de las proteínas estudiadas. Resultados Los resultados de esta tesis muestran que el envejecimiento disminuye la corriente de calcio (ICa), parámetro electrofisiológico que también está reducido en la FA, así como del contenido de calcio del retículo sarcoplásmico (RS), del calcio transitorio global y de las principales proteínas reguladoras del calcio, lo que conjuntamente podría reducir la contracción auricular en los ancianos. Estos resultados fueron reproducidos en modelo animal de envejecimiento prematuro (Zmpste24-/-) que no procesan correctamente la proteína lamina, reforzando la noción que este mecanismo podría subyacer a los efectos del envejecimiento sobre la homeostasis del calcio en las miocitos cardíacos. Además se encontró que en pacientes con previa historia de FA, el envejecimiento tenía un efecto sumatorio sobre algunos efectos deteriorantes de la FA sobre el manejo de calcio, acentuando así a disminución de la ICa con la edad. El estudio de las variantes de riesgo en el cromosoma 4q25 muestra que la variante de riesgo rs13143308T por sí sola o junto con rs2200733T están asociadas a alteraciones electrofisiológicas típicas de la FA. Así, miocitos de pacientes portadores de estas variantes tenían una mayor frecuencia de liberación espontánea de calcio, corrientes de entrada transitorias (ITIs) y despolarizaciones de membrana espontaneas. Estos resultados son los primeros en proporcionar un mecanismo electrofisiológico que podría explicar la mayor incidencia de FA en individuos con variantes de riesgo en 4q25. Estudios electrofisiológicos en miocitos auriculares de un modelo de ratón con deficiencia auricular de Pitx2 (NppaCre+Pitx2fl/-) reproduce todas las alteraciones en la homeostasis del calcio observados en pacientes con variantes de riesgo 4q25. Estos resultados avalan la noción de que la modulación del calcio intracelular por Pitx2 juega un papel importante en procesos electrofisiológicos asociados a la FA. El análisis de potenciales efectos sinérgicos entre variantes de riesgo en 4q25, envejecimiento y la FA revelaba que el envejecimiento per se no modifica los efectos que tiene las variantes 4q25 sobre la homeostasis del calcio. Sin embargo, dado que el envejecimiento reduce la amplitud de la ICa, lo cual reduciría el periodo refractario auricular, podría favorecer la prolongación o el mantenimiento de episodios de arritmia inducidas por actividad eléctrica espontanea. Por lo tanto, es posible que las variantes de riesgo 4q25 constituyan un sustrato electrofisiológico arritmogénico que favorece el inicio de episodios arrítmicos auriculares, y que el envejecimiento actúe prolongando la duración de estos episodios al reducir el periodo refractario auricular a través de la reducción de la amplitud de la ICa. Conclusiones El envejecimiento modula la homeostasis del calcio en miocitos auriculares humanos mediante la disminución de la Ica, del calcio transitorio y del calcio acumulado en el RS. Estos cambios favorecen por un lado el deterioro progresivo de la función contráctil con la edad, y por otro el acortamiento del período refractario mediado por la reducción de la amplitud de la ICa. El modelo murino Zmpste24-/- reproduce los efectos observados reforzando el mecanismo propuesto. Las variantes de riesgo localizadas en la región cromosómica 4q25, concretamente rs13143308 por sí sola o junto con rs2200733, aumentan la liberación espontánea de calcio, ITI y despolarizaciones de la membrana, parámetros característicos de la FA, pudiendo originar eventos arrítmicos en pacientes portadores de las variantes de riesgo. El modelo murino con deficiencia parcial de Pitx2 (NppaCre+Pitx2fl/-) reproduce lo observado en humanos portadores de las variantes de riesgo, reforzando la idea de Pitx2 como nexo entre las variantes de riesgo 4q25 y las alteraciones que provocan en la homeostasis del calcio. La combinación de los efectos encontrados en este estudio propondría a las variantes de riesgo en 4q25 como un substrato arritmogénico que favorece la iniciación de episodios arrítmicos y al envejecimiento como factor que los prolongaría debido a la reducción del período refractario producido por la reducción de la amplitud de la ICa.
Oliveira, Vanessa Resende. „Analise da variabilidade da frequencia cardiaca em mulheres na pos-menopausa sedentarias e treinadas“. [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275215.
Der volle Inhalt der QuelleDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Fisica
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Resumo: O objetivo deste estudo foi analisar e comparar a magnitude das respostas cardiovasculares de mulheres na pós-menopausa sedentárias e treinadas durante as condições de vigília em repouso (VIG) e sono (SONO) a partir do estudo da variabilidade da freqüência cardíaca (VFC). Foram estudas 15 mulheres pós-menopausadas, todas as usuárias de Terapia de Reposição Hormonal (TRH) consideradas clinicamente saudáveis que foram divididas em dois grupos distintos: 6 sedentárias (SED) e 9 fisicamente treinadas há pelo menos doze meses (TRE). Inicialmente as voluntárias foram submetidas a uma anamnese para sua caracterização individual e verificação dos critérios de inclusão e exclusão do grupo estudado. Em seguida, as mulheres pósmenopausadas selecionadas passaram por avaliações: antropométrica e clínica (ginecológica e cardiológica) para afastar a possibilidade de patologias que pudessem interferir nos resultados do presente estudo. Foram coletados os dados referentes ao comportamento autonômico da freqüência cardíaca nas condições de vigília em repouso e sono através da eletrocardiografia dinâmica (HOLTER) de 24 horas e tais dados foram utilizados para a análise da VFC nos domínios do tempo (DT) e da freqüência (DF). A análise da VFC no DT incluiu a média dos intervalos RR (iRR) e seu desvio padrão (DPiRR), enquanto no DF foram estudados os componentes espectrais de baixa (BF: 0,04 ¿ 0,15 Hz) e alta freqüência (AF: 0,15 ¿ 0,40), e a relação BF/AF. Diferenças estatisticamente significantes foram aceitas quando os intervalos de confiança da mediana não se sobrepuseram (p<0,05). Quando comparados os valores medianos dos grupos (SED=73,7 e TRE=64,4bpm) constatamos que a variável Média da FCVIG foi estatisticamente inferior para o grupo TRE (p<0,05). Já para a variável Média da FCSONO (SED=65,5 e TRE=56,2bpm), os valores não atingiram diferença estatisticamente significativa entre os grupos. Para a Média iRR tanto na condição de vigília quanto no sono, as diferenças entre os valores encontrados (SED=749,28 e TRE=916,88ms) e (SED=859,84 e TRE=1059,31ms) foram estatisticamente inferiores (p<0,05) para o grupo SED quando comparados ao grupo TRE. Não houve diferenças estatisticamente significativas entre os grupos para as variáveis DPiRR, BF, AF e BF/AF em nenhuma das condições estudadas (VIG e SONO)
Abstract: The aim of this survey was to analyze and compare the magnitude of the cardiac autonomic activity of women in the one after menopause during the conditions of vigil in rest (VIG) and sleep (SLEEP) through heart rate variability (HRV). Fifteen postmenopausal women were studied, all of them users of Hormone Replacement Therapy (HRT) considered clinically healthy that were divided in two distinct groups: six sedentary and nine physically trained in a regular and extended way, over twelve months. Firstly the volunteers were submitted to anamneses with the aim of gathering necessary information to include the volunteers in the research. Then the selected status postmenopausal women went through some evaluations: anthropometrics and clinical (gynecological and cardiological) to evaluate the physical conditions and drive away the possibility of pathologies that could interfere in the results of the present survey. The referential data were gathered to the heart rate autonomic behavior in the conditions of vigil in rest and sleep through a 24-h dynamic electrocardiography (HOLTER) and such data were used for the analysis of HRV parameters in time (TD) and frequency (FD) domains. HRV analysis in TD included mean RR interval length (iRR) and its standard deviation (SDNN), while in FD, low frequency (LF: 0,04 ¿ 0,15 Hz) and high frequency (HF: 0,15 ¿ 0,40 Hz) spectral components and the LF/HF ratio were analyzed. Statistical significance was accepted when median confidence intervals did not overlap for p< 0,05. When compared the group values (73,7 and 64,4) for the HRVIG variable, we verified that the difference was statically meaningful (p< 0,05). As for the HRSLEEP (65,5 and 56,2), there was no statistical meaningful difference between the groups. For the Mean iRR in the vigil and sleep conditions the differences between the found values (749,28 and 916,88) and (859,84 and 1059,31) were much lower (p< 0,05) for the sedentary group when compared to the physically trained group. There were no differences with statistical meaning between the groups for the variables SDNN, LF, HF and LF/HF in any of the conditions (vigil and sleep)
Mestrado
Mestre em Educação Física
Antonáccio, Renata. „Idoso com insuficiência cardíaca: significados atribuídos à sua condição de adoecimento e ao tratamento“. Universidade Estadual de Campinas, 2017. https://repositorio.ufjf.br/jspui/handle/ufjf/7137.
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PROQUALI (UFJF)
Com a mudança ao longo dos dois últimos anos do perfil de morbimortalidade da população idosa, a doença cardiovascular representa hoje, no Brasil, a maior causa de morte. Existem estudos sobre a insuficiência cardíaca no idoso com enfoque na área biológica, porém há escassez de trabalhos que abordem o problema pela ótica do próprio idoso doente. Assim objetivamos estudar os significados de ser portador de insuficiência cardíaca sob a ótica de pacientes idosos. Trata-se de um estudo que empregou a metodologia clínico-qualitativa. Os sujeitos foram idosos a partir de 60 anos de idade, com insuficiência cardíaca, atendidos em dois hospitais. Utilizamos as técnicas de entrevista não dirigida e observação participante para coletar dados e o método de análise de conteúdo para analisá-los. Para ancorar esta pesquisa, o referencial teórico utilizado foram os estudos desenvolvidos por Perestrello e a psicossomática de Mello Filho. Participaram da pesquisa 11 idosos. Após as análises, emergiram duas categorias: “O Significado de estar com insuficiência cardíaca”, com as subcategorias: 1. O sentido iminente da morte e o medo de morrer. 2. Do desamparo vivido ao amparo familiar. 3. Aspectos emocionais que antecedem a cirurgia e a necessidade de comunicação; e a segunda categoria “Tratamento recebido durante a hospitalizado”, com a subcategoria: 1. Cuidado humanizado num hospital, 2. Equipe multidisciplinar e comunicação. Percebemos que por estarem doentes e terem que passar por cirurgia cardíaca, surgiram emoções que os colocaram em uma condição de limitação, tanto física como mentalmente que lhes causou tristeza, medo de morrer e angústia pelo desconhecido. Pudemos observar que a comunicação, quando não estabelecida de forma adequada e clara, não facilita o entendimento do paciente ao que lhe é dito, deixando-o com medo e ansioso, a ponto de fazê-lo desistir do tratamento. No que tange à forma como foram tratados pelos profissionais no hospital, no período de internação, os idosos relataram respeito, zelo e carinho, além de postura alegre, atenção, dedicação de alguns minutos de conversa e educação no convívio com eles. Destaca-se como resultado importante e curioso o fato de não necessariamente apresentarem extrema preocupação por estarem fisicamente incapacitados devido à doença ou por serem idosos, mas com o fato de que a morte os afastaria do convívio com seus familiares. Trata-se de um sentimento inverso de perda, uma vez que demonstram subliminarmente a necessidade de afeto imediato dos seus familiares. Os idosos do estudo têm espírito jovem e objetivos para as suas vidas. Assim sendo, concluímos que deve ser aperfeiçoada a comunicação dos profissionais de saúde com o idoso portador de insuficiência cardíaca, por meio do ensino de técnicas que os auxiliem a manter um canal de comunicação mais efetivo. Torna-se importante a manutenção do acolhimento, percebido nas falas dos pacientes, quando se referem à equipe de saúde, e a capacitação da equipe de enfermagem para um cuidado humanizado. Fundamental também que o trabalho multiprofissional seja cada vez mais uma realidade.
Over the past two years following some shifts in the morbidity and mortality profile of the elderly population, cardiovascular disease is currently the leading cause of death in Brazil. There are a number of studies focusing heart failure among the elderly specifically in the biological area, but there seems to be a lack of research approaching the subject from the perspective of the elderly patient himself/herself. Thus our purpose is to investigate the meanings of being a patient with heart failure considering the older population. This is a study using the clinical-qualitative methodology among elderly people aged over 60 suffering from heart failure assisted in two hospitals. Non-directive interviews, participant observation and the method of content analysis were used to collect data and analyze them. As a theoretical framework the studies carried out by Perestrello as well as Mello Filho psychosomatics approach were used. Eleven elderly participants joined the research. Following the analysis, two categories have emerged: "The Meaning of being a heart failure patient", with some subcategories: 1. The sense of our impeding death and the fear of dying. 2. From experiences of helplessness to family support. 3. Emotional Aspects arising before the surgery and the need for Communication; and the second category: "Treatment provided by the health team to the hospitalized patient" with the subcategory: 1. Treatment for hospitalized elderly: care with humanization, multidisciplinary teamwork and communication. As a result, it was observed that due to the fact that they are ill and facing the need to undergo a cardiovascular surgery some emotions came to the surface creating conditions of physical and mental limitation which may be the cause of sadness, fear of death and anguish of the unknown. We could note that when communication does not happen properly or clearly, the understanding process becomes more difficult for the patient, causing fear, anxiety and even a wish to abandon treatment. The patients’ experience about how they were treated during the hospitalization period involves respect, caring and affection delivered by nursing technicians, registered nurse, physician, cleaning and catering service employees. They spent time with professionals who maintained a positive attitude, providing attention, talking to them and demonstrating politeness during the interaction. As an interesting finding we may remark that they express deep concern not about being physically disabled because of the disease or advanced age, but rather due to the fact that if they die they will no longer be among their families which constitutes a backward sense of loss. Besides they demonstrate an underlying need to get more affection from family members and fell mentally renewed, ready to reach goals in life. We conclude therefore that communication with the patient should be improved by means of teaching techniques that enable professionals to keep a more effective communication channel open with regard to the understanding of illness and treatment in elderly heart failure patients. It becomes relevant to make patients feel cared, as it was mentioned by them approaching the health team, and prepare the nursing team to provide humanized care allowing multiprofessional teamwork to be increasingly feasible.
Ewers, Irina. „Avaliação imunológica de idosos no pré e pós-operatório de correção de valvulopatia cardíaca“. Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/5/5146/tde-16062009-130002/.
Der volle Inhalt der QuelleIt is known that the immune system, through a phenomenon called immunosenescence, undergoes functional changes during life which may culminate in a diminished capacity of response, turning the subject more susceptible to infections and other pathologies. In this context, it is useful to search for factors that alter this natural evolution, mainly able to delay this process. For this reason, we assessed different immunologic parameters before and after cardiac valve surgery in 65 year-old patients. Our results did not point to a postoperative immunedeficiency-like state, once that the cutaneous tests to PPD, candidin and tricophytin remained positive for most of the subjects. When the proliferative response was assessed in vitro, there were also no differences. On the other hand, we observed a post-surgical increase in the percentage of T CD3 +, T CD4 + cells and in monocytes from peripheral blood when we compare both periods. Moreover, it is important to highlight that activation markers, such as CD25, CD69 and CD95 were also presented in higher levels. According to the cytokine secretion, our results appointed to a greater secretion of IL-4 and IL-8 postoperative. Conversely, reduced concentrations of IL-2, IL-12 and IFN- were detected in supernatant of PBMCs when stimulated in vitro. In summary, our data reveal that the cardiac valve surgery with extra corporeal procedure and anesthesia is able to alter several parameters of the immune response, with an increased percentage of the major assessed cells, as well as in the expression of activation markers and cytokine secretion
Seixas, Mariana Balbi. „Efeito do exercício muscular inspiratório sobre a modulação autonômica cardíaca em idosos“. Universidade Federal de Juiz de Fora (UFJF), 2017. https://repositorio.ufjf.br/jspui/handle/ufjf/5617.
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O treinamento muscular inspiratório promove efeitos crônicos positivos sobre variáveis fisiológicas em diferentes populações, incluindo idosos. No entanto, o conhecimento dos efeitos agudos cardiovasculares promovidos pelo exercício muscular inspiratório (EMI) ainda é escasso. Considerando-se que o envelhecimento fisiológico prejudica a modulação autonômica cardíaca e que esta é visivelmente afetada pela respiração, torna-se relevante investigar as respostas aguda e tardia de uma sessão de EMI sobre o controle autonômico dos batimentos cardíacos em idosos. Para isso, quinze idosos não tabagistas e sedentários, foram submetidos aleatoriamente à duas sessões de exercício: EMI de moderada intensidade (40% da pressão inspiratória máxima) e Sham (sem carga resistiva). A modulação autonômica cardíaca foi avaliada pelas seguintes medidas de variabilidade da frequência cardíaca (VFC) calculadas nos domínios do tempo e da frequência: duração média dos intervalos R-R normais (MNN), desvio padrão dos intervalos R-R normais (SDNN), raiz média quadrática da diferença entre intervalos R-R normais sucessivos (RMSSD), potências espectrais de baixa (LF) e alta frequência (HF), em unidades absolutas (ms2) e normalizadas (u.n.), e razão LF/HF. O efeito agudo foi estudado pela comparação das medidas de VFC obtidas a partir do sinal do eletrocardiograma (ECG) de curta duração na condição basal (antes do exercício) e na recuperação por uma hora pósexercício (Rec 1 = 10’- 15’; Rec 2 = 25’- 30’; Rec 3 = 40’- 45’e Rec 4 = 55’- 60’). O efeito tardio foi investigado pela análise das medidas de VFC obtidas pelo sinal do ECG de longa duração, coletado por equipamento de monitorização ambulatorial, comparando cada hora após a colocação do aparelho em relação à primeira hora, e também os períodos de vigília-noite (18:00 às 21:00), sono (00:00 às 05:00) e vigília-dia (08:00 às 14:00), determinados pelos registros nos diários dos participantes. O teste de análise de variância de duas entradas para medidas repetidas, seguido do post hoc de Tukey, foi empregado para todas as comparações, sendo considerado nível de significância α = 5%. Adicionalmente, foi calculado o tamanho do efeito (d de Cohen) para avaliação da magnitude do efeito agudo observado em cada sessão de exercício. Agudamente houve aumento significativo do MNN (P <0,001) durante toda a recuperação. Além disso, as medidas SDNN (P = 0,01), RMSSD (P <0,001) e as potências espectrais LF (ms2) (P < 0,001) e HF (ms2) (P < 0,001) aumentaram significativamente a partir da Rec 2 em comparação ao basal. Não foram encontradas diferenças para as demais medidas, bem como entre as sessões de exercício para nenhuma variável. A análise do d de Cohen mostrou que a carga moderada potencializou o efeito agudo observado nas medidas de VFC. De forma tardia, as intervenções não promoveram efeitos significativos na modulação autonômica cardíaca, já que as alterações observadas ao longo das horas subsequentes às sessões de exercício e nos períodos de sono e vigílias relacionam-se às mudanças inerentes ao ritmo circadiano: aumento de medidas que refletem a modulação vagal durante o sono. Assim, concluiu-se que uma sessão EMI de moderada intensidade promove melhora aguda da modulação autonômica cardíaca e não gera efeitos tardios significativos nas medidas de VFC em idosos.
Inspiratory muscle training promotes positive chronic effects on physiological variables in different populations, including the elderly. However, knowledge is scarce in relation to the acute cardiovascular effects promoted by the inspiratory muscle exercise (IME). Considering that physiological aging impairs cardiac autonomic modulation and that it is noticeably affected by breathing, it becomes relevant to investigate the acute and late responses of a single IME session on the autonomic control of the heart beats in elderly. Fifteen non-smokers and sedentary elderly were randomly assigned to two exercise sessions: moderate intensity IME (40% maximal inspiratory pressure) and Sham (no resistive load). Cardiac autonomic modulation was assessed by the following measures of heart rate variability (HRV) calculated in time and frequency domains: mean duration of normal RR intervals (MNN), standard deviation of normal RR intervals (SDNN), root of the mean square differences of successive normal RR intervals (RMSSD), power of the spectral bands of low (LF) and high (HF) frequencies in absolute (ms2) and normalized (n.u.) units, and LF/HF ratio. The acute effect was studied by comparing the HRV measures obtained from the short-term electrocardiogram (ECG) signal at baseline (before exercise) and for one hour post-exercise recovery (Rec 1 = 10’- 15’; Rec 2 = 25’- 30’; Rec 3 = 40’- 45’and Rec 4 = 55’- 60’). The late effect was investigated by the analysis of the HRV measures obtained from the long-term ECG signal, collected continuously by ambulatory monitoring equipment, comparing every hour after the device was placed in relation to the first hour, and also between the periods wake-night (18:00 to 21:00), sleep (00:00 to 05:00) and wake-day (08:00 to 14:00), determined by the participant’s records. The two-factor analysis of variance with repeated measures was used for all comparisons, followed by Tukey's post hoc, and significance level α = 95% was considered. In addition, the effect size (Cohen's d) was calculated to assess the magnitude of the acute effect observed in each exercise session. There was a significant increase in MNN (P <0.001) throughout the recovery. In addition, SDNN (P = 0.01) and RMSSD (P <0.001) measures and LF (ms2) (P <0.001) and HF (ms2) (P <0.001) spectral bands increased significantly from Rec 2 compared to baseline. No differences were found for the other HRV measures, as well as between the exercise sessions for neither variable. The analysis of Cohen's d showed that the moderate load potentiated the acute effect observed in HRV measures. Late, interventions did not promote significant effects on cardiac autonomic modulation, since the changes observed during the hours following the exercise sessions and in the sleep and wake periods are related to the changes inherent to the circadian rhythm: increase of measures that reflect vagal modulation during sleep. Thus, it was concluded that a single moderate-intensity IME session promotes an acute improvement in cardiac autonomic modulation and does not generate significant late effects on HRV measures in elderly men.
Bonjorni, Lélia Arantes. „Complexidade da variabilidade da frequência cardíaca na síndrome da fragilidade“. Universidade Federal de São Carlos, 2014. https://repositorio.ufscar.br/handle/ufscar/5324.
Der volle Inhalt der QuelleBackground: Frailty is a critical state of physiological complexity loss. Evaluation measures of complexity could contribute for a better comprehension regarding the frailty process. Objective: to evaluate complexity of HRV, at rest and after postural change, on frailty syndrome. Design: cross-sectional. Setting: community. Subjects: 100 individuals over 60 years old, distributed in groups according to the frailty phenotype: frail (n=8), pre-frail (n=46) and non-frail (n=46). Methods: The electrocardiogram was made in supine and orthostatic postures, for 10 minutes in each position. Sequences of 256 RR intervals were analyzed through linear (spectral analysis low frequency in normalized units (LFnu) and high frequency in absolute units (HFabs)) and non-linear methods (symbolic analysis 0V% and 2UV%, Shannon entropy (SE), conditional entropy (normalized complexity index NCI)). Results: The NCI did not show difference among the evaluated groups in rest supine, however NCI presented reduced values in all 3 groups after orthostatic challenge. Except AFabs, other indices did not differ between groups at rest supine. Conclusion: The results of this study indicate that there is no decrease of complexity on frailty syndrome, possibly because it already presents decreased values with the senescence. The postural change was unable to detect any impairment in HRV complexity associated with the frailty process.
A fragilidade é um estado crítico de perda da complexidade fisiológica, que resulta em maior vulnerabilidade. Medidas de avaliação da complexidade poderiam contribuir para melhor compreensão sobre o processo de fragilização. Objetivo: avaliar a complexidade da variabilidade da frequência cardíaca (VFC), em repouso e após mudança postural, na síndrome da fragilidade. Desenho experimental: estudo transversal. Ambiente de pesquisa: comunidade. Sujeitos: 100 idosos maiores de 60 anos, divididos em grupos, segundo o fenótipo da fragilidade: frágil (n=8), pré-frágil (n=46) e não-frágil (n=46). Métodos: O eletrocardiograma foi coletado na postura supina e ortostática, por 10 minutos em cada posição. Trechos de 256 intervalos RR foram analisados por metodologias lineares (análise espectral baixa frequência em unidades normalizadas (BFun) e alta frequência em unidades absolutas (AFabs)), bem como não lineares (análise simbólica - 0V% e 2VD%, entropia de Shannon (ES), entropia condicional (índice de complexidade normalizado - ICN)). Resultados: o ICN não apresentou diferenças entre os grupos avaliados, no entanto teve seus valores reduzidos em todos os grupos após a mudança postural. Com exceção da AFabs, os demais índices não diferiram entre os grupos, na condição de repouso supino. Conclusão: Os resultados deste estudo indicam que não há redução da complexidade na síndrome da fragilidade, possivelmente pelo fato desta já apresentar valores reduzidos na senescência. A resposta da complexidade cardíaca à mudança postural não apresentou diferenças na presença da síndrome da fragilidade.
Kalil, Luciana Mara Pinto. „Treinamento físico e freqüência cardíaca em ratos idosos: avaliação da freqüência cardíaca intrínseca e da modulação autonômica, do repouso ao exercício de intensidade progressiva escalonada“. Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/5/5131/tde-17102014-111641/.
Der volle Inhalt der QuelleWe studied the effect of exercise training on heart rate (HR), on intrinsic heart rate (IHR), on vagal effect (VE), on vagal tone (VT), on sympathetic effect (SE) and on sympathetic tone (ST) during both treadmill resting and exercise of progressive intensity (four 5-min stages at 5, 7.5, 10 and 15 m.min-1) in old rats. HR responses to crescent doses of ?-adrenergic (isoproterenol) and muscarinic (metacholine) agonists were also verified. We used 20 male Wistar rats randomly assigned to two groups: trained (T, 28+2 months, 460+36 g) and sedentary control (S, 28+2 months, 461+43 g) rats. T was submitted to a ten-week moderate intensity exercise training program, while S was just handled, three to five times a week, for nine weeks and submitted to five-min bouts of daily exercise during the tenth week for taming and to become accustomed to experimental environment. Double pharmacological blockades (propranolol/ methylatropine and methylatropine/propranolol) were performed in order to determine IHR. Autonomic influences on heart rate were evaluated using also unilateral autonomic pharmacological blockade, which allowed us to measure VE and VT as well as SE and ST. Definitions: VE = HR after atropine - control HR, SE = control HR - HR after propranolol, VT = IHR - HR after propranolol, ST = HR after atropine - IHR. HR was recorded on a beat-to-beat basis with a 500 Hz acquisition frequency (AT/CODAS). For statistical analysis we used two-way ANOVA for repeated measurements with contrast, considering a P<0.05 as statistically significant. T rats had lower HR as well as IHR than their sedentary counterparts both at rest and during all progressive exercise stages: HR = 296+6,T vs. 325+16,S; 374+33,T vs. 420+29,S; 380+39,T vs. 423+29,S; 407+46,T vs. 434+25,S; 441+48,T vs. 455+30,S, respectively; and IHR = 288+28,T vs. 312+18,S; 302+27,T vs. 332+24,S; 301+30,T vs. 339+26,S; 308+30,T vs. 344+30,S; 316+31,T vs. 348+31,S, respectively. Vagal activity was not significantly different between groups, either considering VE or VT. Sympathetic influence was also similar between S and T considering both SE and ST in all of the studied conditions. T and S responded similarly to both muscarinic and ?-adrenergic agonists. Both HR and IHR increased from rest to exercise and with increasing exercise intensity. Vagal activity decreased from rest to exercise but only in high intensity exercise. Sympathetic activity increased from rest to exercise and also with increasing exercise intensity. We concluded that in old rats: a) exercise training of moderate intensity led to resting bradycardia and attenuation of exercise tachycardia essentially due to the decrease in IHR; and b) independently from exercise training status, sympathetic stimulation contributed to HR increase from light to high intensity exercise while vagal withdrawal became important only at high intensity exercise
Moura, Ana Paula Frigo. „Plasticidade da inervação cardíaca durante o desenvolvimento pós-natal em préas (Galea spixii, Wagler, 1831)“. Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-09122014-124106/.
Der volle Inhalt der QuelleThe stellate ganglion (SG) is a main component of extrinsic cardiac innervation and is involved in the genesis of various cardiomyopathies. During ageing, the neural control of heart in mammals is altered in the complex shape and unclear, generally cause decrement in the cardiac function and a greater propensity to degenerative diseases. The occurrence of discordant results regarding the morphoquantitative parameters during ageing, such as increase or decrease in the total number of sympathetic neurons, is a subject for interesting discussions. This research was conducted in males preas (Galea spixii), a small rodent of the Brazilian fauna. Therefore, this work aimed to study the effect of postnatal development (maturation and ageing) in the macro and microstructure of the left stellate ganglion (LSG) in preas by dimensional quantitative microscopy (Stereology) associated to immunohistochemistry techniques. According to a specific stage of postnatal development, the animals were allocated into the following age groups: Newborn, Young, Adult and Elderly. The animals were euthanised and the left stellate ganglia were collected and fixed in 4% formaldehyde solution in PBS. A systematic uniformly random sampling (SURS) was performed to estimate: the volume of LSG, neuron volume and the total number of LSG neurons. The main findings of this study were: i) increase in length ganglia - 42% between Newborn and Elderly; 34% between Young and Elderly and 35% between Adult and Elderly; ii) hypertrophy of LSG - 171% between the groups Newborn and Adult; iii) increase of non-neuronal tissue - 268% between the groups Newborn and Adult; iv) stability for the total number of uninucleate neurons, binucleate neurons and total (uni+bi); v) stability in the size (volume) of uninucleate and binucleate neurons; and, vi) stability for the total number of neurons immunorreactive to Ki-67 (uni+bi). It is expected that the results generated for this research may clarify structural aspects of neural plasticity during the postnatal development of preas, thus advancing the knowledge about the extrinsic cardiac innervation
TORLASCO, CAMILLA. „EFFECTS OF MEDIUM-TERM, UNSUPERVISED, MILD INTENSITY PHYSICAL TRAINING ON CARDIOVASCULAR REMODELLING AND KNEE JOINT DAMAGE IN YOUNG AND MIDDLE-AGED HEALTHY SEDENTARY INDIVIDUALS“. Doctoral thesis, Università degli Studi di Milano-Bicocca, 2021. http://hdl.handle.net/10281/306603.
Der volle Inhalt der QuelleBackground. Healthy ageing is associated with changes in human’s body ability to modify organs and systems structure and function in response to stimuli. With this project we sought to understand whether remodelling in response to a stimulus, exercise training, altered with healthy ageing and to deepen the knowledge about running effects on the knee joint. Methods. 237 untrained healthy male and female subjects volunteering for their first-time marathon were recruited. At baseline and after 6 months of unsupervised training, race completers underwent tests including 1.5T cardiac magnetic resonance, brachial and non-invasive central blood pressure (BP) assessment and a 3.0T bilateral knee magnetic resonance. Biological “aortic age” was calculated from the baseline chronological age-stiffness relationship. Change in stiffness was assessed at the ascending (Ao-A) and descending aorta at the pulmonary artery bifurcation (Ao-P) and diaphragm (Ao-D). For analysis, runners were divided by age (O35: ≥35y.o.; U35: 34y.o.) Results. Injury and completion rates were similar among groups. 138 runners (under 35 [U35]: n=71, females=49%; over 35 [O35]: n=67, females=51%) completed the race. On average, U35 were faster by 37 minutes (12%). Training induced a small increase in left ventricle (LV) mass in both groups (3g/m2, p<0.001), but U35 also increased ventricular cavity sizes (LV end-diastolic volume [EDV]i +3%; LV end-systolic volume [ESV]i +8%; right ventricle [RV] EDVi +4%, RVESVi +5%; p<0.01 for all). Systemic aortic compliance fell in the whole sample by 7% (p=0.020) and, especially in O35, also systemic vascular resistance (-4% in the whole sample, p=0.04) and blood pressure (systolic/diastolic, whole sample: brachial -4/-3 mmHg, central -4/-2 mmHg, all p <0.001; O35: brachial -6/-3 mmHg, central -6/-4 mmHg, all p<0.001). At baseline, a decade of chronological ageing correlated with a decrease in Ao-A, Ao-P, and Ao-D distensibility by 2.3, 1.9, and 3.1 x 10-3 mm Hg-1, respectively (p < 0.05 for all). Descending aortic distensibility increased (Ao-P: 9%; p = 0.009; Ao-D: 16%; p = 0.002), while remaining unchanged in the Ao-A. These translated to a reduction in “aortic age” by 3.9 years (95% CI: 1.1 to 7.6 years) and 4.0 years (95% CI: 1.7 to 8.0 years) (Ao-P and Ao-D, respectively). The benefit was greater in older, male participants with slower running times (p < 0.05 for all). Pre marathon and pretraining MRI showed signs of damage, without symptoms, to several knee structures in the majority of the 82 middle-aged volunteers. However, after the marathon, MRI showed a reduction in the radiological score of damage in subchondral bone marrow oedema in the condyles of the tibia (p=0.011) and femur (p=0.082). Conclusion. Medium-term, unsupervised, mild intensity physical training in healthy sedentary individuals induces measurable remodelling of both heart and vasculature. This amount is age-dependent, with predominant cardiac remodelling when younger and predominant vascular when older, with a reduction in central blood pressure and aortic stiffness equivalent to a ~ 4-year reduction in vascular age. Training for and running a marathon is associated with improvement in the condition of bone marrow and articular cartilage.
Neves, Valéria Ferreira Camargo. „Efeito da terapia estrogênica sobre o controle autonômico da freqüência cardíaca e a capacidade aeróbia de mulheres saudáveis“. Universidade Federal de São Carlos, 2007. https://repositorio.ufscar.br/handle/ufscar/5085.
Der volle Inhalt der QuelleUniversidade Federal de Sao Carlos
The effects of female sex hormones on the cardiovascular system have been the topic of much discussion and controversy in the literature. Nevertheless, many scientists believe that estrogens play an important cardioprotective role in premenopausal women, with their effects being observed directly on blood vessels or indirectly by the promotion of an antiatherogenic lipid profile. In recent years, studies have reported that estrogen hormone levels may also influence autonomic control of heart rate (HR) and exercise tolerance. However, other researches have found no modification of these parameters in function of hormone therapy. Within this context, three studies were conducted to verify whether estrogen therapy (ET) could attenuate the age-related decline in autonomic control of HR under resting and exercise conditions and aerobic capacity of healthy women. Thirteen young women (mean age: 24 years), 10 postmenopausal women undergoing ET (PMET, mean age: 53 years) and 15 postmenopausal women not undergoing ET (PMnET, mean age: 56 years) were studied. Hormonal treatment consisted of 0.625 mg/day of conjugated equine estrogens. In the first study, the effect of age and ET on HR variability (HRV) under resting conditions in the supine and sitting positions was evaluated. HRV was analyzed by time (TD) and frequency domain (FD) methods. In this study, higher values of the temporal indices of HRV were observed for the young group. In the analysis of FD, the PMnET group presented lower values in the indices reflecting vagal activity and higher values in the indices reflecting sympathetic activity compared to the young group (supine position) and to the PMET group (sitting position). These results suggest that HRV decreases during aging and that ET may attenuate this process by promoting a reduction of sympathetic activity on the heart and contributing to the cardioprotective effect of estrogen hormones. In the second study, the effect of age and ET on the autonomic control of HR during dynamic exercise and anaerobic threshold (AT) was evaluated. Dynamic exercise was performed on a cycle ergometer starting at 15 W and followed by 5 W increments, until the loss of HR response stabilization was identified by a semiparametric model, characterizing AT. The autonomic control of HR during exercise was analyzed by vagal withdrawal at the beginning of exercise and by calculating the rMSSD index of the stable interval of each workload level. The vagal withdrawal and the rMSSD index were higher for the young group at the workloads studied. The young group also presented higher workload and HR values at AT compared to the postmenopausal groups. These results suggest that autonomic modulation of HR during exercise and aerobic capacity are strongly influenced by age. Hypoestrogenism and ET had no effect on the variables studied. In the third study, the effect of age and ET on cardiorespiratory responses during a cardiopulmonary exercise test was evaluated. This test was performed on a cycle ergometer with 10 to 20 W/min increments until physical exhaustion. The AT was determined by graphic visual analysis of the curves for carbon dioxide output and oxygen uptake ( O2). Higher workload and HR values both at AT and at the peak of exercise were observed for the young group. HR was similar between groups at AT and significantly higher at peak exercise for the young group. The percentages of AT in relation to peak exercise for O2 and HR values were higher for the postmenopausal groups. These results suggest that ET had no effect on cardiorespiratory responses during the incremental exercise test. In conclusion, the results obtained in the three studies suggest that the vagal-protective effect of estrogen hormones detected at rest is not maintained during exercise. In addition, exercise tolerance does not seem to depend on the physiological levels of estrogens. On this basis, the present findings support the importance of the prescription of physical exercise in the clinical orientation for climacteric women
Os efeitos dos hormônios sexuais femininos sobre o sistema cardiovascular tem sido um tópico de muita discussão e controvérsias na literatura. Apesar disso, muitos cientistas acreditam que os estrogênios exercem importante papel cardioprotetor nas mulheres pré-menopausadas, sendo seus efeitos observados diretamente sobre os vasos sangüíneos ou indiretamente através da promoção de um perfil lipídico antiaterogênico. Nos últimos anos, tem sido reportado que o controle autonômico da freqüência cardíaca (FC) e a tolerância ao exercício também podem ser influenciados pelos níveis hormonais de estrogênios. No entanto, outros pesquisadores não encontraram qualquer modificação nesses parâmetros em função da terapia hormonal. Dentro desse contexto, foram realizados três estudos, com o objetivo de verificar se a terapia estrogênica (TE) poderia atenuar o declínio relacionado à idade no controle autonômico da FC, em condições de repouso e exercício, e na capacidade aeróbia de mulheres saudáveis. Para isso foram estudadas 13 mulheres jovens (média etária de 24 anos), 10 na fase pós-menopausa em uso de TE (PMCTE: média etária de 53 anos) e 15 na pós-menopausa sem uso de TE (PMSTE: média etária de 56 anos). A TE consistiu de 0,625 mg/dia de estrogênios eqüinos conjugados. No primeiro estudo, foi avaliado o efeito da idade e da TE sobre a variabilidade da FC (VFC) durante o repouso, nas posições supina e sentada. A VFC foi analisada no domínio do tempo (DT) e da freqüência (DF). Nesse estudo foram observados maiores valores dos índices temporais de VFC para o grupo jovem. Na análise no DF, o grupo PMSTE apresentou menores valores dos índices que refletem a atividade vagal e maiores valores dos índices que refletem a atividade simpática em relação aos grupos jovem (posição supina) e PMCTE (posição sentada). Esses resultados sugerem que a VFC diminui com o envelhecimento e que a TE pode atenuar esse processo, promovendo uma redução na atividade simpática sobre o coração, e contribuindo para o efeito cardioprotetor dos hormônios estrogênios. No segundo estudo, foi avaliado o efeito da idade e da TE sobre o controle autonômico da FC durante exercício dinâmico e o limiar de anaerobiose (LA). O exercício dinâmico foi realizado em cicloergômetro, sendo iniciado na potência de 15 W e seguido por incrementos de 5 W, até que fosse identificada a perda da estabilização da resposta da FC pelo modelo semiparamétrico, caracterizando o LA. O controle autonômico da FC durante o exercício foi analisado por meio da retirada vagal no início do exercício e pelo cálculo do índice rMSSD do trecho estável de cada nível de potência. A retirada vagal e o índice rMSSD foram maiores para o grupo jovem, nas potências estudadas. As jovens também apresentaram maiores valores de potência e de FC no LA em relação aos grupos na pós-menopausa. Esses resultados sugerem que a modulação autonômica cardíaca durante o exercício e a capacidade aeróbia são fortemente influenciados pela idade. Ambos, hipoestrogenismo e TE, não exerceram qualquer influência sobre as variáveis estudadas. No terceiro estudo, foi avaliado o efeito da idade e da TE sobre as respostas cardiorrespiratórias durante teste de exercício cardiopulmonar. Esse teste foi realizado em cicloergômetro, com incrementos de 10 a 20 W/min até a exaustão física. O LA foi determinado visualmente pela análise das curvas de produção de dióxido de carbono e de consumo de oxigênio ( O2). Foram observados maiores valores de potência e de FC tanto no LA como no pico do exercício para o grupo jovem. A FC foi similar entre os grupos no LA e, significantemente maior no grupo jovem, no pico do exercício. Os valores percentuais do LA em relação ao pico do exercício para os dados de O2 e de FC foram maiores para os grupos na pós-menopausa. Esses resultados sugerem que a TE não teve influencia sobre as respostas cardiorrespiratórias durante teste de exercício incremental. Finalizando, os resultados obtidos nos três estudos sugerem que o efeito protetor vagal dos hormônios estrogênios evidenciado durante o repouso não se mantém durante o exercício. Além disso, a tolerância ao exercício parece não depender dos níveis fisiológicos dos estrogênios. Desse modo, nossos achados reforçam a importância da prescrição de exercícios físicos na orientação clínica das mulheres no climatério
Silva, Cristiane Rocha da. „Comparação dos valores de recuperação da frequência cardíaca e do índice cronotrópico após teste de Bruce em esteira em mulheres idosas obesas com alta e baixa força muscular“. Universidade Católica de Brasília, 2018. https://bdtd.ucb.br:8443/jspui/handle/tede/2426.
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The aim of the present study was to analyse heart rate recovery (HRR) and chronotropic index (CI) after treadmill Bruce test in obese elderly women classified on the basis of relative manual grip strength. Methods: Eighty-eight obese elderly women who were between the ages of 60 and 87 participated in the study and were categorized and enrolled to one of two groups based on lower (< 1.51 m²) or higher (≥ 1.51 m²) relative handgrip strength, respectively. The heart rate recovery in the first and second minutes following the treadmill exercise test and the chronotropic index were compared between groups. Results: The higher relative handgrip strength group presented a significantly higher peak heart rate (p= 0,019) during exercise and a faster HRR at the first (p = 0.003) and second minutes (p = 0.002) after the ergometric test compared to the low manual grip strength group (p=0,001). Furthermore, there was a tendency (p = 0.059) towards a significantly higher CI, six-minute walk test (p = 0.001) and low time up and go time in the group of high relative manual grip strength compared to the low force group. Conclusion: In conclusion, elderly women with greater relative handgrip strength also demonstrated a better heart rate response during and following exercise and tendency to higher chronotropic index, possibly indicating better autonomic balance.
O objetivo do presente estudo foi analisar a recuperação da frequência cardíaca (RFC) e o índice cronotrópico (IC) após teste de Bruce em esteira em mulheres idosas obesas classificadas com base na força de preensão manual relativa (FPMR). Métodos: Participaram voluntariamente do estudo 88 mulheres idosas obesas entre 60 e 87 anos que foram categorizadas em dois grupos: baixa força de preensão manual relativa (<1,51 m²) e alta força de preensão manual relativa (≥ 1,51 m²). A RFC no primeiro e no segundo minutos e o índice cronotrópico após o teste ergométrico em esteira foram comparados entre os grupos. Resultados: O grupo de alta força de preensão manual relativa apresentou valores de frequência cardíaca máxima significativamente maiores durante o teste ergométrico (p= 0,019), RFC mais rápida no primeiro (p = 0,003) e segundo minutos (p = 0,002) após o teste ergométrico comparado ao grupo de baixa força de preensão manual relativa (p=0,001). Observamos tendência (p = 0,059) em direção a um IC significativamente maior, Teste de caminhada de 6 minutos (p = 0,001) e baixo tempo no time up and go no grupo de alta força de preensão manual relativa comparado ao grupo de baixa força. Conclusão: Mulheres idosas com alta força de preensão manual relativa apresentam uma melhor resposta da frequência cardíaca durante e após o teste ergométrico, tendência a um índice cronotrópico superior possivelmente indicando um melhor equilíbrio autonômico após o esforço físico e maior capacidade funcional.
Melo, Ruth Caldeira. „Efeitos do envelhecimento e da atividade física regular em índices da variabilidade da freqüência cardíaca e da arritmia sinusal respiratória de homens saudáveis“. Universidade Federal de São Carlos, 2004. https://repositorio.ufscar.br/handle/ufscar/5198.
Der volle Inhalt der QuelleUniversidade Federal de Minas Gerais
The purpose of the present study was to evaluate the effects of the aging and the regular physical activity on the autonomic control of heart rate (HR) at rest and during deep breath test (DBT) in healthy men. Nine young sedentary (mean = 22.67 ±2.45 years), sixteen young active (mean = 22.38 ±2.13 years), eight sedentary older (mean = 63.5 ±2.39 years) and eight older active (mean = 61 ±1.6 years) men were studied. Electrocardiogram was continuously recorded during 15 minutes (rest), 4 minutes (DBT, with breath rate at 5 to 6 cycles/minute) and 1 minute (recovery) in supine position. The HR (bpm) and the R-R intervals (RRi) (ms) were analyzed by time (RMSSD index) and frequency domain methods. The power spectral components were expressed as absolute (a) and normalized units (nu) at low (LF) and high (HF), and as the LF/HF. The HR and the RRi were analyzed by the respiratory sinus arrhythmia (RSA) indices: expiration/inspiration ratio (E/I) and inspiration-expiration difference (∆IE). The HR was lower in the activity groups than to the matched-age sedentary groups. The older sedentary group had lower heart rate variability (HRV), E/I and ∆IE than young ones. The older active group showed higher RMSSD and HF component than matched-age sedentary group (45.04 and 28.78 ms, 58,167 and 12,218 ms2/Hz, P<0.05; respectively). No differences were found between young and older active groups for RMSSD (61.71 and 45.04 ms, respectively) and HRV (TP:130,816 and 125,710, LFa:33,295 and 32,611, HFa:84,346 and 58,167, ms2/Hz, respectively) and DBT indices (E/I: 1.40 and 1.35, ∆IE: 23 and 18, respectively). The results show that aging associates with inactivity reduces the HRV. However, the regular physical activity increases the HRV, independent of age, suggesting attenuation the effects of the aging in the autonomic control of the heart rate.
O presente estudo teve como objetivo avaliar os efeitos da idade e da atividade física regular sobre o controle autonômico da freqüência cardíaca (FC) durante o repouso e durante a manobra para acentuar a arritmia sinusal respiratória (MASR) em homens saudáveis. Participaram do presente estudo, 9 jovens sedentários (média= 22,67 ±2,45 anos), 16 jovens ativos (média= 22,38 ±2,13 anos), 8 idosos sedentários (média= 63,5 ±2,39 anos) e 8 idosos ativos (média= 61 ±1,6 anos). O traçado eletrocardiográfico foi registrado durante 15 minutos (repouso com respiração espontânea), 4 minutos (MASR, com freqüência respiratória mantida entre 5 a 6 ciclos/minuto) e 1 minuto de recuperação. A freqüência cardíaca (FC), em bpm, e os intervalos RR (iR-R), em ms, foram analisados pelo domínio do tempo (índice RMSSD) e pelo domínio da freqüência. Os componentes da potência espectral foram expressos em valores absolutos (a) e em unidades normalizadas (un) para a densidade total de potência (DTP), as bandas de baixa freqüência (BF), alta freqüência (AF) e razão BF/AF. A FC obtida durante a manobra MASR foi analisada a partir dos índices: razão expiração/inspiração dos iR-R (E/I) e de sua variação durante a inspiração-expiração (∆IE). Os grupos ativos apresentaram valores inferiores de FC de repouso em comparação aos controles sedentários de mesma idade. O grupo idoso sedentário apresentou menor variabilidade da variabilidade da freqüência cardíaca (VFC), E/I e ∆IE que o grupo jovem sedentário. O grupo idoso ativo mostrou valores superiores de RMSSD e da banda de HF em relação ao grupo sedentário idoso (45,04 e 28,78 ms, 58.167 e 12.218 ms2/Hz, p<0,05; respectivamente). Diferenças estatísticas não foram encontradas entre o grupo jovem ativo e idoso ativo para o RMSSD (61,71 e 45,04 ms, respectivamente) e para a VFC (DTP: 130.816 e 125.710, LFa: 33.295 e 32.611, HFa: 84.346 e 58.167, ms2/Hz, respectivamente) e para os índices da ASR (E/I: 1,40 e 1,35, ∆IE: 23 e 18, respectivamente). Para os grupos sedentários foi observado correlação negativa entre os índices DTP, AFa, E/I e ∆IE e a idade (p<0,05), sendo que o mesmo não pode ser observado nos grupos ativos. Os resultados sugerem que o envelhecimento associado ao sedentarismo provoca reduções na VFC, representadas pela diminuição da atividade vagal sobre o coração, determinada tanto pela análise no domínio da freqüência como pelos índices da arritmia sinusal respiratória. Entretanto, a atividade física regular aumenta a VFC, independentemente da idade, e atenua as alterações, decorrentes do processo de envelhecimento, no controle autonômico da freqüência cardíaca.
Arakelian, Vivian Maria. „Estudo dos ajustes cardiorrespiratórios e metabólicos durante o exercício resistidos em jovens e idosos - proposta de avaliação da carga crítica no Leg Press 45º“. Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/82/82131/tde-20072012-153709/.
Der volle Inhalt der QuelleThe resistance training has been strongly encouraged, providing favorable effects on muscular strength and endurance, cardiovascular function, metabolism and cardiovascular risk reduction. However, there is little literature about the cardiovascular, ventilation and metabolic responses in resistance exercise in the elderly. Moreover, little is known about such adjustments in the critical load (CL), which indicates the transition of moderate to intense exercise in this type of exercise. Thus, the objectives of this study are: To evaluate the cardiovascular, respiratory and metabolic changes during resistance exercise (leg press 45º) at different intensities and to determine the intensity of the CL and even that intensity to compare the responses of heart rate (HR), systolic blood pressure (SBP), ventilation (VE), oxygen consumption (\'VO IND.2\'), production of carbon dioxide (\'VCO IND.2\'), respiratory quotient (RQ), perceived exertion (PSE) and blood lactate ([Lac]) obtained during exercise between two groups (young and old). Participated in this study 28 males, 15 young and 13 elderly, apparently healthy, with an average age of the young was 22.7 ± 2.5 years, mean weight 77.6 ± 10.2 kg and mean height of 180.0 ± 10.0 cm, and in the elderly the average age was 68.6 ± 4.0 years, mean weight 76.7 ± 7.5 kg and mean height of 170.0 ± 1.0 cm, non-alcoholic non-smoker, and without cardio-respiratory, neurological, metabolic and joints disorders. During all procedures were monitored BP, HR and ECG at MC5, DII and V2 modified, and were carried out: 1RM resistance exercise on the leg press at 45º; exercise stress test dynamic resistance with different percentages of 1RM tested agreement for obtaining the critical load, the linear regression of the points made during the construction of the graph: load X reverse of time (time = duration of exercise until fatigue). Regarding the execution time and number of repetitions no differences between the groups (p = 0.25 and p = 0.49, respectively) for the HR and SBP, we have exacerbated response of HR for a young group compared to elderly, during exercise (p < 0.0001), and the SBP appears to be so contrary, so there is more pronounced for the elderly group (p < 0.0197). The [Lac] was greater in young people in the CC intensity (p = 0.0014), as well as the value of PSE (0.00021). For the ventilatory parameters (VE, \'VO IND.2\' and \'VCO IND.2\') have higher values in the young group also during the exercise for different intensities, mainly in the CC (p < 0.0001 for the three variables). Furthermore, it was possible to determine the CL for both groups, and this was around 38% 1RM (p = 0.22). Thus, this was the first study that evaluated and compared the physiological responses between young and old in different intensities of 1RM in the exercise of Leg Press 45º, as in CL.
Perseguini, Natália Maria. „Estudo da modulação autonômica cardíaca no processo de envelhecimento e suas relações com a terapia de reposição hormonal, proteína C-reativa e comprimento de telômeros“. Universidade Federal de São Carlos, 2014. https://repositorio.ufscar.br/handle/ufscar/5177.
Der volle Inhalt der QuelleUniversidade Federal de Minas Gerais
The aging process affects many systems of the human body, including: autonomic nervous system, which can be assessed by heart rate variability (HRV); cellular structures, such as telomere length; and mechanisms of regulation of the inflammatory process, which can be evaluated by inflammatory markers such as high-sensitivity C-reactive protein (hsCRP). The combined analysis of these variables enables the study of the aging process in a multidimensional way. Additionally, the effects of hormone replacement therapy (HRT) on HRV are contradictory. In this way, we conducted the study I, which aimed to investigate the effects of HRT on HRV in healthy postmenopausal women. Two groups were evaluated: Group 1 (G1): 20 women who did not use HRT (60 ± 5.89 years) and group 2 (G2): 20 women undergoing HRT (59 ± 5.70 years). The electrocardiogram was recorded in supine position for 10 min. Spectral analysis included low and high frequency in absolute (LF and HF) and normalized (LFnu and HFnu) units. LF/HF ratio was also calculated. Symbolic analysis (0V%, 1V%, 2LV% e 2UV%), Shannon and conditional entropy were calculated. LF, LFnu and LF/HF ratio were higher, whereas HFnu was lower in G2 than in G1. Correlations between complexity indices and HFnu were significant and positive only in G1. We conclude that women undergoing HRT had higher cardiac sympathetic modulation and reduced cardiac vagal modulation compared to women not using HRT. Moreover, the expected positive relationship between cardiac vagal modulation and HRV complexity was found only in the group not undergoing HRT, indicating that vagal modulation in women under therapy drop below a minimum value necessary to the association to become apparent, suggesting an unfavorable cardiac autonomic modulation in spite of HRT. Considering the findings of the study I, we chose to adopt the use of the therapy as an exclusion criterion for the study II. Thus, the study II aimed to examine the aging effect on heart rate variability in supine and standing, on serum hsCRP and leukocyte telomere length, as well as to verify the age at which the changes caused by aging process are accentuated. One hundred and ten volunteers were divided into five groups according to age: G21-30 years, G31-40 years, G41-50 years, G51-60 years, and G61-70 years. Venous blood samples were collected for measurements of serum hsCRP and telomere length. ECG signals were recorded in rest supine and standing (15 min in each posture). HRV was assessed by spectral analysis in low and high frequencies in absolute (LF e HF) and normalized (LFnu e HFnu) units; symbolic analysis (0V%, 1V%, 2LV% e 2UV%); Shannon entropy; and complexity index (CI) and normalized CI (NCI) from conditional entropy. The main results were: 1) HF and 2UV% reduction (vagal modulation) in G51-60, and 0V% increase (sympathetic modulation) and NCI reduction (complexity) in G61-70, in supine; 2) less efficient response to postural change from supine to standing with advancing age; 3) hsCRP increase in G51-60; 4) telomere shortening in G61-70; 5) in supine, HRV indices showed stronger relationship with the principal component of most relevance from the multivariate principal component analysis, compared to hsCRP and telomere length. Considering that HRV indices in supine had a stronger association with the aging process, we can conclude that the decrease in cardiac vagal modulation may have influenced the increase in serum hsCRP (although normal values), in G51-60, since this effect is described by the cholinergic anti-inflammatory pathway. Decreased cardiac vagal modulation and increased hsCRP may have contributed to the telomere shortening identified in the following decade (G61-70). In this way, we must consider the importance of preventive actions prior to the onset of aging effects, particularly in the 41-50 age range, in an attempt to attenuate the natural effects of senescence.
O envelhecimento exerce influência sobre vários sistemas do corpo humano, dentre eles: sistema nervoso autonômico, que pode ser avaliado pela variabilidade da frequência cardíaca (VFC); estruturas celulares, como o comprimento de telômeros; e mecanismos reguladores de processos inflamatórios, que podem ser avaliados por marcadores inflamatórios, como a proteína C-reativa ultra sensível (PCRus). A análise conjunta dessas variáveis permitiria o estudo do processo de envelhecimento de forma multidimensional. Adicionalmente, são controversos os efeitos da terapia de reposição hormonal (TRH) sobre a VFC. Assim, foi realizado o estudo I, o qual teve por objetivo investigar os efeitos da TRH na VFC em mulheres pós-menopáusicas saudáveis. Foram avaliados dois grupos: grupo 1 (G1): 20 mulheres que não faziam uso de TRH (60 ± 5,89 anos) e grupo 2 (G2): 20 mulheres submetidas à TRH (59 ± 5,70 anos). O eletrocardiograma foi registrado na posição supina por 10 min. A análise espectral incluiu a baixa e a alta frequência em unidades absolutas (BF e AF) e normalizadas (BFun e AFun). A relação BF/AF também foi calculada. A análise simbólica (0V%, 1V%, 2LV% e 2UV%), e entropias de Shannon e condicional também foram calculadas. BF, BFun e a razão BF/AF foram maiores, enquanto AFun foi menor no G2 do que no G1. As correlações entre índices de complexidade e AFun foram significativos e positivos apenas no G1. Concluímos que mulheres submetidas à TRH apresentaram maior modulação cardíaca simpática e menor modulação cardíaca vagal em comparação às que não faziam a terapia. Além disso, a relação positiva esperada entre modulação cardíaca vagal e a complexidade da VFC foi encontrada apenas no grupo não submetido à TRH, indicando que a modulação vagal em mulheres sob a terapia não atinge um valor mínimo necessário para a associação se tornar aparente, sugerindo uma modulação autonômica cardíaca desfavorável, apesar da TRH. A partir dos achados do estudo I, optou-se por adotar, como critério de exclusão para o estudo II, o uso da terapia. Assim, o estudo II teve por objetivo analisar o efeito do envelhecimento sobre a VFC nas posições supina e ortostática, os níveis séricos da PCRus e o comprimento de telômeros leucocitários, além de verificar em qual faixa etária se acentuam as alterações provocadas pelo processo de envelhecimento. Foram avaliados 110 voluntários, divididos em cinco grupos, de acordo com a idade: G21-30 anos, G31-40 anos, G41-50 anos, G51-60 anos e G61-70 anos. Amostras de sangue venoso foram coletadas para medidas de PCRus e comprimento de telômeros. Os sinais eletrocardiográficos foram registrados em repouso nas posições supina e ortostática (15 min em cada postura). A VFC foi avaliada por índices de baixa e alta frequências em unidades absolutas (BF e AF) e normalizadas (BFun e AFun) da análise espectral; índices 0V%, 1V%, 2LV% e 2UV% da análise simbólica; entropia de Shannon; e índice de complexidade (IC) e IC normalizado (ICN) da entropia condicional. Os principais resultados foram: 1) redução de AF e 2UV% (modulação vagal) em G51-60, além de aumento de 0V% (modulação simpática) e diminuição de ICN (complexidade) em G61-70 na posição supina; 2) resposta menos eficiente à manobra de mudança postural de supino para ortostatismo com o avanço da idade; 3) aumento da PCRus em G51-60; 4) encurtamento do comprimento de telômeros em G61-70; 5) na posição supina, os índices da VFC apresentaram relação mais alta com o componente principal de maior relevância, proveniente da análise multivariada por componentes principais, em comparação à PCRus e ao comprimento de telômeros. Considerando-se que os índices da VFC na posição supina apresentaram uma associação mais forte com o envelhecimento, podemos concluir que a diminuição da modulação cardíaca vagal possa ter contribuído para o aumento dos níveis séricos de PCRus (apesar dos valores estarem dentro de faixa de normalidade), na faixa etária de 51 a 60 anos, uma vez que este efeito é descrito pela via anti-inflamatória colinérgica. A diminuição da modulação cardíaca vagal e o aumento da PCRus podem ter contribuído para o encurtamento de telômeros, identificado na década seguinte, de 61 a 70 anos. Dessa maneira, torna-se importante a proposição de ações preventivas em faixas etárias anteriores ao início das alterações provocadas pelo envelhecimento, especialmente na década de 41 a 50 anos, na tentativa de atenuar os efeitos naturais da senescência.
Melo, Ruth Caldeira de. „Efeitos do envelhecimento e do exercício físico sobre o sistema cardiovascular de indivíduos saudáveis“. Universidade Federal de São Carlos, 2008. https://repositorio.ufscar.br/handle/ufscar/5099.
Der volle Inhalt der QuelleUniversidade Federal de Sao Carlos
The ageing process is known to affect different tissues and systems. It is well-established that age-associated changes in cardiovascular structure and function are related to the risk of cardiovascular diseases. Because of the vast amount of cardiovascular modifications observed with ageing, the present study focused on three important topics: heart rate variability (HRV), blood pressure variability (BPV) and endothelial dysfunction. Furthermore, we also investigated the effects of physical activity (endurance and strength) on the autonomic control of heart rate (HR), which might be used as non-pharmacological therapy. Thirty five young subject between 18 and 30 years old (14 sedentary men, 5 sedentary women and 16 active men) and thirty eight middleaged/older subjects between 55 and 70 years old (16 sedentary men, 14 sedentary women and 8 active men) were studied. In addition, the subjects are distributed among 3 different studies. In the first one, the effects of the ageing process and active life-style on the autonomic control of HR were investigated in young and middleaged/older subjects. Electrocardiogram was recorded during 15 minutes of rest and 4 minutes of controlled breathing (5 to 6 cycles/min) in the supine position. HR and RR intervals were analyzed by time and frequency domain methods. The active groups presented lower HR and higher HRV (time domain) than the sedentary groups, whereas both middle-aged/older groups showed lower HRV (frequency domain). Additionally, interaction between ageing and life-style effects was observed for respiratory sinus arrhythmia (ASR) indexes (calculated during the controlled breathing test). The sedentary middle-aged/older group presented lower ASR magnitude than the other groups studied. The results suggest that ageing reduces HRV, however, regular physical activity improves vagal modulation on the heart and, consequently, attenuates the effects of ageing on the autonomic control of HR. In the second study, we aimed to investigate if strength training is able to improve cardiac autonomic control in healthy middle-aged/older men. HRV was evaluated before and after 12 weeks of isokinetic eccentric strength training (2days/week, 2-4 sets of 8-12 repetitions at 75-80% peak torque), involving knee flexion and extension. Strength training decreased the systolic blood pressure and increased the torque. However, an autonomic imbalance towards sympathetic modulation predominance was induced by an unknown mechanism. In the third study, we evaluated the effect of ageing on the BPV and endothelial function. We also sought for correlations between increased BPV and impaired endothelium dependent-dilation (EDD) in the middle-aged/older group. Intra-brachial artery BPV and conduit vessel EDD (brachial artery flow-mediated dilation, FMD) were determined in healthy young and middle-aged/older subjects. Moreover, endothelial function of resistance vessels was evaluated by venous occlusion plethysmoghaphy in the middle-aged/older group. The young group presented lower systemic oxidative stress, lower systolic BPV and higher FMD compared with the middle-aged/older group. After split this group according to the BPV, lower FMD was observed in the middleaged/older group with higher BPV. In addition, FMD was inversely correlated to BPV. The lower BPV group showed a great reduction (55%) in the forearm blood flow responses when NG-monometyl-L-arginine (nitric oxide inhibitor) was co-infused with acetylcholine (vs 14% in the higher BPV group). The results suggest that ageing process increases BPV and reduces endothelial function. Additionally, middle-aged/older subjects with higher BPV also have impaired EDD compared with their peers with lower BPV. General Conclusions: the results from the studies described above suggest that ageing process causes decrease of HRV, increase of BPV and decrease of endothelial function. Moreover, aerobic exercise has a cardioprotector effect, since it was able to attenuate the ageing effects on the cardiac vagal modulation. This same benefit, however, was not observed after 12 weeks of eccentric strength training. On the other hand, the strength training program performed by healthy older subjects modified the sympato-vagal balance toward the sympathetic modulation. Finally, systolic BPV oscillations seem to have a narrow relationship with vasodilation mediated by nitric oxide. Then, more studies are needed to clarify the cause-effect relation between those important variables.
O envelhecimento é um processo complexo que causa alterações em vários sistemas do organismo. Em relação ao sistema cardiovascular, modificações na sua estrutura e função estão diretamente relacionadas com o risco aumentado de desenvolvimento de doenças cardiovasculares em idosos. Dentre as diversas alterações cardiovasculares observadas com o envelhecimento, apenas as relacionadas à variabilidade da freqüência cardíaca (VFC), variabilidade da pressão arterial (VPA) e disfunção endotelial foram abordadas no presente estudo. Além disso, foram também investigados os efeitos de dois tipos distintos de exercício físico, ou seja, de resistência aeróbia e de força muscular, sobre o controle autonômico da freqüência cardíaca (FC) de sujeitos saudáveis, como uma forma alternativa de terapia não-farmacológica. Participaram do presente estudo: 35 sujeitos jovens na faixa etária de 18 a 30 anos (14 homens sedentários, 5 mulheres sedentárias e 16 homens ativos) e 38 sujeitos meia-idade/idosos na faixa etária de 55 a 70 anos (16 homens sedentários, 14 mulheres sedentárias e 8 idosos ativos), os quais estão distribuídos em 3 estudos distintos. No primeiro estudo, os efeitos do envelhecimento e do estilo de vida sobre o controle autonômico da FC foram investigados em jovens e meiaidade/idosos com padrão de vida sedentário ou ativo. O sinal eletrocardiográfico foi obtido durante 15 minutos de repouso e 4 minutos de respiração controlada (5-6 ciclos/min), ambos na posição supina. A FC e os intervalos RR foram analisados no domínio do tempo e da freqüência. Adicionalmente, os índices da arritmia sinusal respiratória (ASR) também foram calculados. Os grupos ativos apresentaram menor FC e maior VFC (domínio do tempo) em relação aos grupos sedentários, enquanto que ambos os grupos idosos apresentaram menor VFC (domínio da freqüência). Além disso, foi observado interação entre idade e estilo de vida, já que a magnitude da ASR foi menor no grupo meia-idade/idoso sedentário comparativamente aos demais grupos. Os resultados indicam que a VFC reduz com o aumento da idade. Entretanto, a atividade física regular produz efeitos positivos sobre a modulação vagal cardíaca e, conseqüentemente, atenua os efeitos do envelhecimento sobre o controle autonômico da FC. No segundo estudo, foi avaliado se o treinamento de força excêntrica é capaz de modificar o controle autonômico da FC de idosos saudáveis. A VFC foi avaliada, durante o repouso supino e sentado, após 12 semanas de treinamento de força isocinética excêntrica (extensão e flexão do joelho, 2 dias/semana, 2-4 séries de 8-12 repetições, 75-80% do pico de torque). O treinamento de força foi capaz de aumentar o torque muscular e reduzir a pressão arterial (PA) sistólica de idosos saudáveis. Entretanto, o mesmo causou um desbalanço simpato-vagal, em direção a predominância simpática, o qual foi produzido por mecanismos desconhecidos. No terceiro estudo, foi avaliado se a VPA está aumentada com o avançar da idade e, ainda, se a mesma tem alguma relação com reduções na vasodilatação endotélio-dependente (VED) em sujeitos meiaidade/idosos saudáveis. A VPA intra-arterial e a VED (dilatação mediada por fluxo, DMF) da artéria braquial (i.e., vaso de condutância) foram avaliadas em sujeitos jovens e meia-idade/idosos de ambos os sexos. Adicionalmente, o grupo meia-idade/idoso também foi submetido à pletismografia de oclusão venosa para avaliar a função endotelial dos vasos de resistência. Os jovens apresentaram menor estresse oxidativo sistêmico, menor VPA sistólica e maior DMF, comparativamente ao grupo meia-idade/idoso. Quando esse grupo foi dividido de acordo com a VPA, observou-se DMF reduzida no grupo com alta VPA. Adicionalmente, a DMF mostrou correlação inversa com a VPA. Em relação aos vasos de resistência, o grupo com baixa VPA mostrou redução de 55% na resposta do fluxo sangüíneo quando NG-monometil-L-arginina (inibidor da produção de óxido nítrico) foi co-infudido com acetilcolina (vs 14% no grupo com alta VPA). Os resultados indicam que o envelhecimento causa redução da função endotelial e aumento da VPA. Além disso, sujeitos meia-idade/idosos com alta VPA apresentam DMF reduzida quando comparados aos seus pares com baixa VPA. Conclusão geral: os resultados obtidos nos três estudos sugerem que o envelhecimento causa redução na VFC, aumento da VPA e redução da função endotelial. Além disso, a atividade física aeróbia possui um efeito cardioprotetor, já que essa foi capaz de atenuar os efeitos do envelhecimento sobre a modulação vagal cardíaca. Entretanto, esses efeitos benéficos não foram observados com o treinamento de força excêntrica, pois 12 semanas de treinamento alteraram o balanço simpato-vagal em direção a modulação simpática. Por fim, o aumento nas oscilações da PA sistólica mostrou uma estreita relação com a vasodilatação mediada pelo óxido nítrico, a qual necessita de maiores investigações no sentido de determinar a relação de causa e efeito entre essas duas importantes variáveis.
Lieber, Samuel C. „The effects of aging on cardiac mechanics“. Thesis, 2006. http://library1.njit.edu/etd/fromwebvoyage.cfm?id=njit-etd2006-030.
Der volle Inhalt der Quellede, Lucia Claudio. „β-arrestin 2 deletion improves cardiac function during aging“. Tesi di dottorato, 2018. http://www.fedoa.unina.it/12022/1/deLucia_Claudio_30.pdf.
Der volle Inhalt der QuelleLai, Chao-Hung, und 賴昭宏. „Exercise training enhanced cardiac SIRT1 expression and protected aging induced heart damage in natural aging rats“. Thesis, 2014. http://ndltd.ncl.edu.tw/handle/5qk68t.
Der volle Inhalt der Quelle中國醫藥大學
老化醫學博士學位學程
102
According to the survey data of the Department of Health, Executive Yuan, ROC (Taiwan) in 101 years, it shows that cardiovascular disease has been in the second (9.1%) of the highest in the top ten leading causes of death, when coupled with related cardiovascular disease and its complications, such as cerebrovascular disease in the thrid (9.3%) and hypertension in the tenth (1.3%). Aging is an immutable law. The function of the heart is in the rate of 1% aging per year. With the advent of the aging society, we must study the serious problem of cardiovascular disease. The demonstrated roles of SIRT1, the mammalian counterpart of the yeast SIR2, reveal that SIRT1 regulates important cellular processes including anti-apoptosis, neuronal protection, cellular senescence, aging and longevity. In the previous studies in obesity in the laboratory, mice with high blood pressure and diabetes slowed down the performance of myocardial apoptosis through sports training. Therefore, this study designed a set of experiments with rats, aging and exercise, to obtain detail discussion of myocardial cells signaling transduction pathway changed. Three groups of different ages, 3 months, 12 months and 18 months old ages of mice were randomly divided into the aging groups (C3, A12 and A18) and exercise groups (E3, AE12 and AE18). Exercise training of swimming five times a week gradual increases from the first week of every 20 min to every 60 min for 12 weeks. Finally, after the complete of the sports training process, we used tissue sections to observe the type of organization (H & E stain), as well as the test of apoptosis (TUNEL Assays) and Western blotting to observe changes in the myocardial tissue and protein. Experimental results show that protein expression of cardiac myocyte apoptotic pathway increased in the aging groups (C3, A12 and A18), while the improvement in the exercise group. In the aging groups (C3, A12 and A18), the expression of the protein in the survival pathway increased with age to reduced performance, but in the exercise groups (E3, AE12 and AE18) increase access to improve performance. In addition, we did a preliminary study of myocardial apoptosis upstream SIRT regulation and the performance of the aging groups (C3, A12 and A18) was not obvious and On the contrary, there was much performance in the exercise groups (E3, AE12 and AE18) and it meant compensatory mechanism. On the other hand, we also obtain that aging induced cardiac fibrosis (C3, A12 and A18), via FGF2 / uPA / MMP2 pathway TGFβ1 / CTGF pathway and concentric cardiac hypertrophy via JNK / ERK1/2 / NFATc3 / GATA4 pathway to enhance cardiac injury, and exercise training (E3, AE12 and AE18) can reverse aging-induced cardiac injury. Therefore, we hope that a more in-depth study by our results of this study to investigate the mechanism of aging-induced heart injury.
Hoffmann, Morgana. „Cardiac Aging in Female Wistar Rat Models With Sedentary or Physicaly Active Lifestyle“. Master's thesis, 2013. https://repositorio-aberto.up.pt/handle/10216/69062.
Der volle Inhalt der QuelleHoffmann, Morgana. „Cardiac Aging in Female Wistar Rat Models With Sedentary or Physicaly Active Lifestyle“. Dissertação, 2013. https://repositorio-aberto.up.pt/handle/10216/69062.
Der volle Inhalt der QuelleFares, Elias. „The Impact of Aging and Ovariectomy on Cardiac Contractile Function in Isolated Ventricular Myocytes“. 2012. http://hdl.handle.net/10222/15388.
Der volle Inhalt der QuelleWright, Stephen. „Left Atrial Phasic Function during Exercise: The Role of Atrioventricular Coupling“. Thesis, 2013. http://hdl.handle.net/1807/43337.
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