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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

The utility of bioimpedance cardiography in assessing the influence of obstructive sleep apnea hypopnea syndrome on cardiac function

Aron, Adrian 20 April 2010 (has links)
Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS) is a breathing disorder characterized by recurrent episodes of upper airway collapse during sleep. Measuring cardiac function in OSAHS patients may provide information to help delineate not only chronic effects of autonomic imbalance and ventricular loading in the diseases state, but also possible beneficial effects of clinical treatments. Objectives (Study 1): The aim of this study was to determine the reproducibility of select cardiac variables when monitoring a simulated sleep apnea event using a new improved bioimpedance cardiography system. Methods: Fifteen apparently healthy males were tested on three different days in a protocol requiring their performance of two 15 sec and two 30 sec forced and sustained inspiratory efforts against a closed epiglottis (Müeller Maneuver-MM). Results: Changes in cardiac output (CO), heart rate (HR), stroke volume (SV), myocardial contractility index (MCI) and systemic vascular resistance (SVR) were similar during 15 sec and 30 sec MM in all three days. During 30 sec MM, these changes in cardiac function were pronounced in comparison to the minimal variations observed for the 15 sec MM challenge test. Objectives (Study 2): The aim of this study was to characterize the cardiac responses to negative intrathoracic pressure in OSAHS patients with and without hypertension versus healthy subjects. Methods: Two groups of 10 OSAHS patients, one without HTN and one with HTN were compared with a control group. Each subject underwent two 30 sec (MM) as previously described. Results: During MM, there were similar changes in SV, HR and SVR in all three groups. CO was lower during MM in controls compared to OSAHS groups, whereas MCI decreased during MM in both controls and OSAHS+HTN groups (-7.5% and -1.7%, respectively) compared with an increase in OSAHS group (11.8%). During a Post-MM, both OSAHS groups showed return of cardiac responses toward their pre-MM baseline within 30 sec. Conclusions: The new bioimpedance cardiograph evaluated in this study was found to be reliable for measuring acute changes in cardiac responses to this breathing challenge test. OSAHS may cause acute changes in selected cardiac parameters during and immediately after a breathing challenge test. / Ph. D.
62

Tělesné složení dětí lišících se pohybovým programem / Body composition in children with different movement programm

Kučera, Jan January 2018 (has links)
Title: Body composition in children with different movement programm Objectives: The main objektive of this work is analysis of body composition while using BIA method children of younger school age and consired differences in physical components with regard to different movement programm. Methodes: Body composition was measured by bioelectrical impedance analysis device Bodystat 1500. Data was processed in Microsoft Excel. Followed parameters are the percentage of body fat, the absolute amount of fat-free mass in kg, the proportion of total body water. The research participated in total 75 probands agend 10-11 years of average height 147,7 cm and weight 42,1 kg. The research includes regularly training 25 children from RC Mountfield Říčany (training 3 times a week + 2x physical education) with a medium to hight intensity exersice of 360 minutes per week, regularly training 25 children from Říčany Fight Club (2x weekly training + 2x physical education) with a medium to hight intensity exersice of 270 minutes per week and 25 children from the Nemo Říčany Elementary School where the physical education 90 minutes per week. The research group is made up of boys only, because girl with a higher percentage of total body fat have a higher BFM then boys. Results: The average proportion of body fat in boys...
63

Textile-enabled Bioimpedance Instrumentation for Personalised Health Monitoring Applications

Ferreira Gonzalez, Javier January 2013 (has links)
A growing number of factors, including the costs, technological advancements, an ageing population, and medical errors are leading industrialised countries to invest in research on alternative solutions to improving their health care systems and increasing patients’ life quality. Personal Health System (PHS) solutions envision the use of information and communication technologies that enable a paradigm shift from the traditional hospital-centred healthcare delivery model toward a preventive and person-centred approach. PHS offers the means to follow patient health using wearable, portable or implantable systems that offer ubiquitous, unobtrusive bio-data acquisition, allowing remote access to patient status and treatment monitoring.Electrical Bioimpedance (EBI) technology is a non-invasive, quick and relatively affordable technique that can be used for assessing and monitoring different health conditions, e.g., body composition assessments for nutrition. EBI technology combined with state-of-the-art advances in sensor and textile technology are fostering the implementation of wearable bioimpedance monitors that use functional garments for the implementation of personalised healthcare applications.This research studies the development of a portable EBI spectrometer that can use dry textile electrodes for the assessment of body composition for the purposes of clinical uses. The portable bioimpedance monitor has been developed using the latest advances in system-on-chip technology for bioimpedance spectroscopy instrumentation. The obtained portable spectrometer has been validated against commercial spectrometer that performs total body composition assessment using functional textrode garments.The development of a portable Bioimpedance spectrometer using functional garments and dry textile electrodes for body composition assessment has been shown to be a feasible option. The availability of such measurement systems bring closer the real implementation of personalised healthcare systems. / 2013-04-29 Licentiatseminarium kl.10-11.30 The presentation will be broadcast using Adobe Connect. For more information contact javier.ferreira@hb.se
64

Tělesné složení extraligových hráčů hokejbalu kategorie U15 - U18. / Body analysis of street hockey players in categories U15-U18

Gärtner, Tomáš January 2016 (has links)
Title: Body analysis of street hockey players in categories U15-U18 Objectives: The main object of this thesis is to determine body analysis of street hockey players playing Extra League in categories younger and older juniors using bioelectrical impedance analysis. Measured data should be compared amonit groups of players aged 15 a 16, 16 and 17, 17 and 18. Methods: In the thesis are used sometometric methods to gather antropometrical parameters and also the bioelectrical impedance analysis of the body structure using the device Tanita BC 418 MA to determine body structures of individual players. Results: We measured and compared selected parameters of body structures of street hockey players (n = 101) in age groups of 15, 16, 17 and 18 years. The differences in the amount of body fat, body fat percentage, free fat mass and bodily fluids amonit individual groups of street hockey players were monitored. Body fat percentage and free fat mass do not depends on age. Amount of body fat and free fat mass depends on age. Ice hockey players are taller and have more fat free mass. In comparison with the antropological research of the players in the same age from the year 2001 we discovered, that present-day players are, on average, 3,68 cm shorter, but they are, on average, 1,5 kg heavier, which is caused...
65

Spectroscopie d'impédance appliquée à la composition corporelle en néphrologie et en dialyse : caractérisation des facteurs d'influence / Bioimpedance Spectroscopy and Body Composition in Nephrology and Dialysis : Factors of Influence

Cridlig, Joëlle 05 June 2013 (has links)
Le but de ce travail est l'étude de la bioimpédancemétrie appliquée à des populations particulières de néphrologie (hémodialyse, insuffisance rénale et transplantation), afin d'évaluer l'apport de cette technique et les facteurs d'influence modifiant la mesure ou son interprétation. Nous avons pu identifier (à travers deux appareils d'impédancemétrie) plusieurs profils de patients, selon leurs « réponses » à la technique de bioimpédance, en fonction des séances d'hémodialyse, de l'âge, des comorbidités, de matériel implantable, de la fonction rénale après transplantation. Il y a une bonne validité des données physiques mesurées. Sur les valeurs calculées, il y a des valeurs aberrantes, tant sur les volumes hydriques que sur le diagnostic d'hydratation (calcul de l'excès d'eau). La principale hypothèse est l'existence d'algorithmes dans les logiciels, établis sur des populations caractéristiques, et avec de nombreux facteurs correctifs, mais qui restent inadaptés dès que le sujet mesuré s'éloigne un peu de ces patients « normés ». La présence de matériel dans le corps humain influencerait les mesures et rendrait les algorithmes inadaptés. Ce travail nous amène à conclure que quelque soit le logiciel, donc l'appareil utilisé, le patient devrait être son propre témoin de mesure, hypothèse non vérifiée dans la littérature. Enfin, le deuxième point de recherche pourrait être la notion d'une fréquence tissulaire propre à chacun, autre que la classique fréquence de 50 kHz, celle théorique à laquelle l'effet capacitif membranaire est maximal, et caractérise donc la cellule. Notre étude montre que cette fréquence est loin d'être de 50 kHz. Les études restent à faire / The goal of this work is to study bioimpedance through different and particular people in nephrology (hemodialysis, renal disease or kidney graft), to assess this electrical engineering and the factors of onfluence that can change the measures or their meaning. We succeed to identify (through two bioimpedance instrument) several profiles of patients, according to their "response and behaviour" to this bioimpedance technique, depending on hemodialysis sessions, age, morbidity, presence of electrical device or after kidney transplantation. Through our population, we find a good validity of the electrical and physical measures. But when the values body composition are calculated from the electrical data, there is often aberrant values, concerning body composition, fluid compartment or the excess water. The main hypothesis is the existence of algorithms in the devices, compiled from statistics on healthy populations, with several corrective factors, but these algorithms probably don't fit with "particular" population. This work allows us to propose that what are the devices used, the patient might be his own measure witness. There is no study in the literature. Finally, an idea could be the existence of a specific tissue frequency, specific to each one, and different from the theoretical frequency of 50 kHz. This 50 kHz frequency corresponds to the highest cell membrane capacity and so characterizes the cell. Our study shows that the frequency corresponding to this highest reactance is precisely not 50 kHz. The hypothesis is the existence of a own characteristic frequency. Sudies remain to be done
66

Implementation of and Electrical Bioimpedance Measurement System for Renal Function Monitoring

Pérez-Vázquez Losada, Sonia January 2008 (has links)
Peritoneal Dialysis is a treatment for patients suffering from renal failure thatallows out-patient care. This means that the patient only needs to visit the hospital forconsultation and not for treatment, increasing considerably the comfort of the patient,while reducing remarkably the cost per patient.In order to increase the level of medical supervision obtained with the periodicvisits to the clinic, televisit has been put into practice in some hospitals. But thesetelevisits are based on indirect and qualitative indicators of renal failure, and thereforethey are just valid for detection of situations near limit cases, such as well over-hydratedor dehydrated.Electrical Bioimpedance Measurements have been proved to constitute anappropriate method for assessment of body composition, and therefore they can providewith direct indicators of body fluid distribution. Such ability of EBI technology allowsthe detection of body fluid unbalance caused by renal dysfunction, and therefore,nephrology televisits would benefit tremendously from EBI measurements.This project is based on the AD5933 Impedance Network Analyzer of AnalogDevices, and the main task is to develop a software application that controls theevaluation board in which it is implemented, and allows the storage of the EBImeasurements in EDF+ files that will facilitate the management of medical data whenapplied to televisit. These files are uploaded to XML format in order to be sent to aremote server, where a software application will have been implemented for medicalconsultation. / Uppsatsnivå: D
67

Análise de parâmetros de impedância bioelétrica, bioquímicos, morfológicos e funcionais em idosos sarcopênicos e não sarcopênicos submetidos a treinamento resistido convencional e com resistência elástica : ensaio clínico aleatório /

Osco, Karla Minacca January 2019 (has links)
Orientador: Luís Alberto Gobbo / Resumo: A população idosa com idade igual ou superior a 60 anos dobrou na última metade do século XX. O envelhecimento é um processo inevitável com consequências deletérias e progressivas para o corpo humano, comprometendo os seus diferentes sistemas, tais como o fisiológico, o morfológico, o funcional e o endócrino. A perda progressiva de massa e força muscular, associada à função é denominada sarcopenia, e como consequência, promove maior risco para incapacidade funcional, fragilidade, quedas, fraturas, hospitalizações, institucionalizações, óbito precoce e alterações imunológicas. Em idosos as alterações no sistema imunológico podem ocorrer devido ao aumento da concentração sanguínea de citocinas pró-inflamatórias que agrava o estado sarcopênico, acarretando um processo de inflamação crônica de baixo grau (LGI, low grade inflammation). Dentre os parâmetros observados na avaliação da sarcopenia, a análise de impedância bioelétrica (BIA) vem sendo utilizada há tempo para mensuração dos diferentes componentes corporais dentro do sistema morfológico, especialmente os tecidos adiposo e muscular. Mais recentemente, parâmetros brutos da BIA (R, resistência e Xc, reatância) têm sido utilizados para a avaliação da saúde celular (PhA, ângulo de fase e a análise de vetores de impedância bioelétrica (BIVA, bioimpedance vector analysis). Com a finalidade de reverter ou atenuar os efeitos deletérios do envelhecimento, programas de treinamento físico, mais especificamente o treinamento resistido... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
68

Influência da sobrecarga de líquidos sobre estado nutricional, gasto energético de repouso e biomarcador de risco cardiovascular em pacientes tratados por diálise peritoneal / Influence of fluid overload on nutritional status, resting energy expenditure and biomarker of cardiovascular risk in patients treated by peritoneal dialysis

Santos, Nathália Zanon dos 21 November 2016 (has links)
A sobrecarga hídrica (SH) é um achado comum em pacientes em diálise peritoneal (DP) e a inadequação do estado nutricional aumenta a morbimortalidade nesta população. A bioimpedância elétrica é um método rápido e não-invasivo para estimar os compartimentos corporais, incluindo a distribuição dos fluídos corporais nos espaços intra e extracelulares. O principal objetivo foi avaliar se a SH interfere em estado nutricional, composição corporal, gasto energético de repouso e um biomarcador de risco cardiovascular, em pacientes com Doença Renal Crônica tratados por DP. Caracterizou-se como um estudo observacional transversal, realizado no Hospital das Clínicas da FMRP-USP. Foram avaliados dados de composição corporal e estado hídrico por Bioimpedância Elétrica de Frequência Simples (BIA) e Bioimpedância Elétrica Multifrequência de Espectroscopia (BIS), a concentração sérica do peptídeo natriurético atrial (Nt pro - BNP) como biomarcador de risco cardiovascular, dados antropométricos, de consumo alimentar, gasto energético de repouso (GER), exames bioquímicos e dados clínicos de rotina dos pacientes. Trinta pacientes foram incluídos e classificados em normohidratados (NH) ou hiperhidratados (HH), pelo valor de sobrecarga hídrica de 1,1 L. Para análise estatística, o nível de significância foi pré-fixado em ?= 0,05. Os pacientes HH, em comparação aos NH, apresentaram além de maior sobrecarga hídrica (3,54 L ± 1,7 X 0,14 ± 0,6), maiores valores em água corporal total (ACT - 34,98 L ± 4,74 X 30,43 L ± 5,45), água extracelular (AEC - 17,91 L ± 2,87 X 13,84 L ± 2,30) e menores valores de ângulo de fase (4,02° ± 0,81 X 5,51° ± 0,77) na avalição por BIS; o Nt Pró - BNP mostrou-se maior nos HH (7686 pg/ml ± 8872 X 1334 pg/ml ± 1034). Não houve diferença significativa entre os grupos para dados antropométricos, nos demais exames bioquímicos, em aferições da força de preensão palmar, nas pontuações do MIS (Malnutrition Inflammation Score), nos dados de ingestão alimentar, e nem no GER. O grupo com sobrecarga hídrica mostrou, de fato, uma maior concentração de água em compartimento extracelular, possivelmente gerando aumento em Nt pro - BNP e menor ângulo de fase. Quando avaliado o grupo como um todo, os métodos (BIA e BIS) mediram os resultados igualmente somente no que se refere à resistência (p = 0,71). Sendo a ACT, água intracelular (AIC), AEC, massa livre de gordura (MLG), massa celular corporal (MCC) e ângulo de fase maiores na medições da BIA e somente massa gorda maior nas medições da BIS; correlações mostraram que os dados de massa livre de gordura e massa celular corporal foram os que mais se distanciaram, com coeficientes mais fracos, enquanto que as demais variáveis apresentaram forte correlação. Para o diagnóstico nutricional em vigência de sobrecarga líquida, deve-se considerar um conjunto de variáveis interpretadas de maneira complementar, possibilitando um diagnóstico nutricional mais detalhado. O uso rotineiro da BIS pode ajudar a refinar a avaliação do estado de hidratação e composição corporal destes pacientes em DP. / The fluid overload (FO) is a common finding in patients on peritoneal dialysis (PD) and the inadequacy of the nutritional status increases the morbidity and mortality in this population. The bioelectrical impedance is a quick and non-invasive method to estimate body compartments, including the distribution of body fluids in intra- and extracellular spaces. The main objective was to assess whether the FO affects body cell mass, nutritional status, resting energy expenditure and a biomarker of cardiovascular risk in patients with chronic kidney disease treated by PD. It is characterized as a cross-sectional observational study conducted at the Hospital of FMRP-USP. We evaluated data of body composition and water status by Simple Frequency Electric Bioimpedance (BIA) and Electric Multifrequency Spectroscopy Bioimpedance (BIS), the serum concentration of atrial natriuretic peptide (NT pro - BNP) as a biomarker of cardiovascular risk, anthropometric data, food intake, resting energy expenditure (REE), biochemical and clinical data from routine patient. Thirty patients were included and classified into normal hydration (NH) or hyper hydrated (HH) by fluid overload value of 1.1 L. For statistical analysis, the level of significance was pre-set at ? = 0.05. HH patients, compared to NH, presented in addition to increased fluid overload (3.54 L ± 1.7 X 0.14 ± 0.6), higher values in total body water (TBW - 34.98 L ± 4.74 ± 5.45 x 30.43 L), extracellular water (ECW - L 17.91 ± 2.87 X 13.84 ± 2.30 L) and smaller phase angle values (± 4.02 ° 0.81 X 5.51 ± 0.77 °) in a BIS appraisal; the Nt Pro - BNP was higher in HH (7686 pg / ml ± 8872 X 1334 pg / ml ± 1034). There was no significant difference between groups for anthropometric data, in other biochemical tests on measurements of grip strength, in scores of MIS (Malnutrition Inflammation Score), the food intake data, and not the REE. The group with fluid overload shows, in fact, a higher concentration of water in the extracellular compartment, possibly generating an increase in NT pro - BNP and lower phase angle. When evaluated the group as a whole, the methods (BIA and BIS) measure only the results also as regards the resistance (p = 0.71). And TBW, intracellular water, ECW, fat-free mass, body cell mass and larger phase angle measurements in the BIA and only greater fat mass in measurements of BIS; correlations show that free mass data of fat and body cell mass are the ones who are more distanced, with weaker coefficients, while the other variables are strongly correlated. For the nutritional diagnosis of fluid overload force, should be considered a set of variables interpreted in a complementary manner, enabling a more detailed nutritional diagnosis. The routine use of BIS can help refine the assessment of hydration status and body composition of these patients on PD.
69

Desenvolvimento de um sistema de bioimpedância elétrica baseado em FPGA / Development of bioimpedance system based on FPGA

Veiga, Emiliano Amarante 02 August 2013 (has links)
Made available in DSpace on 2016-12-12T20:27:37Z (GMT). No. of bitstreams: 1 Resumo - Emiliano.pdf: 94943 bytes, checksum: 29697d95e7130478be8d1ad382dffdeb (MD5) Previous issue date: 2013-08-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Electrical Impedance Spectroscopy (EIS), also called Bioelectrical Impedance Analysis (BIA), is a non-invasive technique used for characterizing the electrical properties of biological materials, but also used for obtaining body composition properties and for analyzing food quality. Most EIS devices contain microcontrollers, digital signal generators and data acquisition boards. Digital Signal Processors (DSP) have also been used to implement EIS systems, but they su_er for multifrequency signal generation. Furthermore, DSPs do not have enough space for data storage. On the other hand, EIS systems based on Field-Programmable Gate Array (FPGA) devices are indicated when signal generation and acquisition demand integration and a very small noise level. In addition, FPGA can be used for getting real time signal processing, as it is a hardware rather than sequential execution of instructions. The bioimpedance measurements consist of injecting a sinewave into the material under study by two electrodes and measuring the resulting voltage by other pair of electrodes, which are placed in an impedance probe. Most EIS systems measure the injecting current by a shunt resistor, and then the real and imaginary part of the impedance of the load under study are calculated for each discrete frequency of the system. In this work, an EIS system is proposed based on FPGA for generating sinusoidal signals in the frequency range 0.1 to 500 kHz. It contains two acquisition channels and an interface for measuring both the modulus and phase of the impedance. A proposed EIS system is fully described. The system performance of the FPGA and the acquisition interface were comprehensively investigated. Experiments using saline solutions were used in order to calibrate the impedance probe used in this work. Measurements in raw bovine milk were made in order to validate the proposed EIS system. The results showed an error of 2% when measuring milk samples in the conductivity range of 1.46 to 2.9 mS/cm. Further measurements were made in order to investigate the e_ects in the impedance spectra due to Somatic Cell Count (SCC) and hydrogen peroxide in the bovine milk. The results showed that the impedance phase spectra are sensitive to SCC at low frequencies. It has also been shown that the impedance phase of the milk adulterated with hydrogen peroxide is almost linear in the frequency range from 1 up to 10 kHz. It was showed that real time measurements and signal processing based on FPGA can be used for developing an EIS system. The proposed system is modular and it can be portable. This might be the case of using this system for measuring and characterizing bovine milk by hand-held or in-milkline instrumentation. / Espectroscopia de Impedância Elétrica (EIE), também conhecida como Análise por Bioimpedância Elétrica, é uma técnica não-invasiva utilizada para determinação das propriedades elétricas de materiais biológicos e também empregada para obtenção da composição corporal e estudo da qualidade de alimentos. Diversos sistemas de EIE são projetados com microcontroladores, sintetizadores de sinais digitais e placas de aquisição. Processadores Digitais de Sinais (DSP) também são utilizados para projetos de sistemas de EIE, porém, eles sofrem falta de recursos para trabalhar com geração e condicionamento de sinais multifrequenciais. Além do mais, não têm espaço de memória su_ciente para o armazenamento de dados. Por outro lado, os sistemas baseados em FPGA são indicados para aplicações que envolvem geração e aquisição de sinais multifrequenciais que exigem forte integração e redução de ruídos na eletrônica. Diferente da execução sequencial de instruções, o FPGA trabalha em tempo real, já que se trata de processamento em hardware. A medição de bioimpedância consiste em injetar uma onda senoidal no material em estudo por meio de dois eletrodos e medir a tensão resultante através de outro par de eletrodos, onde estão fixados em uma sonda de impedância. A maioria dos sistemas de EIE efetuam a medição da corrente usando uma carga de teste e em seguida executam o cálculo da parte real e imaginária da impedância para cada frequência. Neste trabalho, é proposto um sistema de EIE baseado em FPGA para gerar sinais senoidais na faixa de frequência de 0,1 a 500 kHz. É composto de dois canais de aquisição e uma interface para medição de módulo e fase da impedância. Sua arquitetura detalhada está descrita nas seções seguintes, onde o desempenho da geração e aquisição de sinais foram precisamente estudados. Experimentos com soluções salinas foram realizados para calibrar o sistema, e medições com leite bovino foram efetuadas para validação do sistema proposto. Os resultados indicam um erro de 2% na medição de amostras com condutividade entre 1,46 e 2,9 mS/cm. Outras medições foram realizadas para investigar os efeitos no espectro de impedância devido a Contagem de Células Somáticas (CCS) e peróxido de hidrogênio no leite bovino e os estudos mostraram que o espectro de fase é sensível a CCS em baixas freqüências. Também foi possível veri_car que o leite adulterado com peróxido de hidrogênio apresenta fase aproximada a linear na faixa de 1 a 10 kHz. Este trabalho mostrou que a medição em tempo real com arquitetura baseada em FPGA pode ser utilizada para projetar sistemas de EIE. O sistema proposto é modular e pode ser portável, permitindo sua utilização para medição e caracterização do leite bovino inloco manualmente ou por instrumentação usando recipiente com amostra de leite.
70

Regurgitação valvar funcional em insuficiência cardíaca congestiva descompensada: monitoração não-invasiva por bioimpedância cardíaca e ecocardiografia e resposta à terapêutica / Functional valvular incompetence in decompensated heart failure: noninvasive monitoring and response to medical management.

Campos, Paulo César Gobert Damasceno [UNIFESP] 25 November 2009 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:50:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-11-25. Added 1 bitstream(s) on 2015-08-11T03:25:54Z : No. of bitstreams: 1 Publico-11760a.pdf: 1069601 bytes, checksum: 88c7a2d10e394e1888e3b93a69070de4 (MD5). Added 1 bitstream(s) on 2015-08-11T03:25:54Z : No. of bitstreams: 2 Publico-11760a.pdf: 1069601 bytes, checksum: 88c7a2d10e394e1888e3b93a69070de4 (MD5) Publico-11760b.pdf: 1959621 bytes, checksum: 2665d88fb8fec237d73fdc84aa78a26a (MD5) / Introdução: A insuficiência cardíaca congestiva (ICC) descompensada pode ser definida como a evidência de sinais e sintomas de insuficiência cardíaca (IC) ao repouso e representa estado de ativação neuro-hormonal intensa, secundária ao déficit de perfusão renal. Regurgitações valvares funcional mitral e tricúspide são causas reversíveis de diminuição de fluxo sanguíneo sistêmico eficaz. O impacto de tais regurgitações sobre o débito cardíaco, sobre o conteúdo de fluido torácico, sobre as dimensões de câmaras cardíacas e sobre a função do aparato valvular pode ser monitorado de forma não-invasiva, antes e após a otimização do tratamento clínico. Objetivo: Avaliar o papel das regurgitações valvares funcional mitral e tricúspide como causas reversíveis de redução do débito cardíaco em ICC descompensada, e que acompanham a disfunção ventricular sistólica em miocardiopatias isquêmica e não-isquêmica. Métodos: catorze pacientes do sexo masculino (66 ± 8 anos de idade), fração de ejeção (24 ± 5%) secundária às miocardiopatias isquêmica (71%) e não-isquêmica (29%), apresentaram ICC descompensada com evidência clínica de regurgitações valvares mitral e tricúspide, foram avaliados por Bioimpedância cardíaca e ecocardiografia antes e uma semana após otimização de tratamento clínico. Resultados: o tratamento farmacológico de ICC descompensada foi acompanhado de redução de peso corpóreo de 82,9 a 76 kg (P<0,01), elevação no índice cardíaco (de 2,1 para 2,6 L/min/m2; P<0,01), redução na pressão sistólica da artéria pulmonar (de 58 para 35 mm Hg; P<0,001), conteúdo de fluido torácico (de 39 para 32 kOhm; P<0,001) e resistência vascular sistêmica (de 1633 para 1209 dinas/seg/cm5; P<0.001). A melhora dessas regurgitações incluiu redução nas dimensões das câmaras atriais esquerda e direita (de 27 para 24 cm2 e de 26 para 23 cm2, respectivamente; (P<0,001), diminuição das regurgitações mitral e tricúspide detectadas pelo Doppler colorido (P < 0,01), do volume regurgitante mitral (de 105 para 65 ml; P<0,001), e do tamanho efetivo do orifício regurgitante mitral (de 0,8 para 0,6 cm2; P<0,01). Conclusões: Na ICC descompensada, as regurgitações funcionais mitral e tricúspide contribuem para redução do débito cardíaco, aumento do conteúdo fluido torácico e da resistência vascular sistêmica, simultaneamente ao aumento de câmaras atriais e do orifício valvar, os quais podem ser melhorados com tratamento clínico. A bioimpedância cardíaca e a ecocardiografia fornecem avaliação seriada não-invasiva de parâmetros hemodinâmicos e função valvar nestes pacientes. / Objective: We hypothesized that functional mitral and tricuspid valvular incompetence (MR and TR, respectively) are reversible causes of reduced cardiac output in decompensated heart failure (DF) that accompanies systolic dysfunction in ischemic or nonischemic cardiomyopathy. Background: DF, defined as signs and symptoms of heart failure at rest, is rooted in a salt-avid state transduced by neurohormonal activation secondary to impaired renal perfusion. Functional MR and TR are reversible causes of reduced systemic blood flow. Their impact on cardiac output, thoracic fluid content, cardiac chamber dimensions, and valvular apparatus function can be monitored noninvasively, before and after optimized medical management. Methods: Fourteen male subjects (66 ± 8 years old) with reduced ejection fraction (24 ± 5%) secondary to ischemic (71%) or nonischemic (29%) cardiomyopathy, who developed DF with clinical evidence of mitral (MR) and tricuspid (TR) valvular incompetence, were each assessed by bioimpedance and echocardiography before and 1 week after optimized medical management restored compensated failure. Results: Pharmacologic elimination of DF was accompanied by a reduction in body weight (p<0.01). Hemodynamic improvements included a rise in cardiac index (2.1 to 2.6 L/min/m2; p<0.01) and a reduction in predicted pulmonary artery systolic pressure (58 to 35 mm Hg; p<0.001), thoracic fluid content (39 to 32 kOhm; p<0.001), and systemic vascular resistance (1633 to 1209 dynes/sec/cm5; p<0.001). Improvements in functional MR and TR included reductions in left and right atrial areas (27 to 24 cm and 26 to 23 cm2, respectively; p<0.001), color-flow grading of MR and TR severity (p<0.01), mitral regurgitant volume (105 to 65 mL; p<0.001), and effective MR orifice size (0.8 to 0.6 cm2; p<0.01). Conclusions: In DF, functional MR and TR contribute to reduced cardiac output, increased thoracic fluid content, and systemic vascular resistance, together with enlarged atria and valvular orifice size, which can be improved by medical management. Bioimpedance and echocardiography provide for serial noninvasive assessments of hemodynamic status and valvular function in such cases. / TEDE / BV UNIFESP: Teses e dissertações

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