INTRODUÇÃO: Não há, até o momento, método ideal de avaliação da função renal em fetos com dilatação de vias urinárias. A ultrassonografia é utilizada como um método não invasivo e alguns parâmetros, como o índice de líquido amniótico, foram descritos na predição de insuficiência renal. Entretanto, a sensibilidade é baixa e a detecção de alterações, muitas vezes, ocorre tardiamente na gestação. A avaliação bioquímica da urina ou sangue fetais acrescenta risco à gestação e, apesar de melhorar a detecção de insuficiência renal, tem sensibilidade e especificidade baixas. O Power Doppler tridimensional é um método capaz de quantificar fluxo em órgãos parenquimatosos e tem sido utilizado na quantificação de fluxo sanguíneo de órgãos fetais e placenta. Como fetos com obstrução de vias urinárias e insuficiência renal apresentam diminuição no número de glomérulos, a quantificação do fluxo renal ao Power Doppler tridimensional poderia aprimorar a avaliação da função renal desses fetos. OBJETIVOS: quantificar o fluxo renal ao Power Doppler tridimensional em fetos com suspeita de obstrução de vias urinárias e naqueles com morfologia renal normal, avaliar a influência da profundidade nos índices vasculares e comparar os índices nos fetos que evoluíram com e sem insuficiência renal no período pós-natal. MÉTODOS: fetos com hidronefrose bilateral e/ou dilatação vesical foram prospectivamente comparados com fetos sem malformações em relação à quantificação do fluxo renal ao Power Doppler tridimensional. Os parâmetros avaliados foram IV, IVF, IF e a profundidade. Após o nascimento, as crianças foram seguidas por uma equipe de nefrologia e urologia e, de acordo com a função renal, foram classificadas em 2 grupos: insuficiência renal e função renal normal. A vascularização renal foi avaliada em cada grupo e comparada ao grupo controle. RESULTADOS: vinte e três fetos com dilatação de vias urinárias e setenta e três com morfologia renal normal foram considerados para a análise estatística. Cinco crianças (21,7%) apresentaram insuficiência renal após o nascimento. IV e IVF foram significativamente mais baixos nos casos que apresentaram insuficiência renal do que naqueles com função renal normal (p=0,009 e 0,036, respectivamente). Os três índices corrigidos pela profundidade (IVCP, IFCP e IVFCP) variaram com a idade gestacional e a variação inter-observador melhorou quando eles foram utilizados. A porcentagem do IVCP e do IVFCP em relação à controles de mesma idade gestacional foi menor nos casos que desenvolveram insuficiência renal do que naqueles que evoluíram com função renal normal. CONCLUSÕES: IV e IVF foram significativamente mais baixos em fetos que evoluíram com insuficiência renal pósnatal, porém a profundidade foi um fator interferente importante. Desta forma, IVCP e IVFCP são potencialmente melhores na avaliação de fetos com suspeita de obstrução de vias urinárias. Como os índices corrigidos pela profundidade variam de acordo com a idade gestacional, é necessária a construção de curvas de normalidade por idade gestacional para que os referidos índices possam ser avaliados na prática clínica / INTRODUCTION: There is no ideal method for prenatal evaluation of renal function whether there is a urinary tract dilatation in the fetus. Although ultrasound is a noninvasive method and some parameters have been described to evaluate fetal renal function, as amniotic fluid index, there is a lack of sensitivity to renal failure when ultrasound is used alone. Furthermore, ultrasound changes may appear late in pregnancy. Biochemical evaluation of fetal urine or blood may expose the fetus to some risk, and still lack sensitivity and specificity for renal failure. Threedimensional Power Doppler evaluation has been used to quantify blood flow in fetal organs and placenta. As urinary tract obstruction lead to decrease in renal glomeurli and consequently to a decrease in parenchymal renal flow, three-dimensional quantification of renal flow may improve the evaluation of fetal renal function in fetuses with renal dilatation. OBJECTIVES: To evaluate the ability of threedimensional evaluation of renal vascularization to predict postnatal renal prognosis in fetuses with suspicion of urinary obstruction and to analyze depth influence in vascular indexes. METHODS: Fetuses with bilateral hydronephrosis and/or bladder dilatation had renal vascularization evaluated by three-dimensional ultrasound and VOCAL and were prospectively compared to healthy fetuses. Parameters evaluated were VI, VFI, FI and the distance between the probe and the renal cortex. Follow up by urologists and nephrologists allowed us to allocate these fetuses in two groups: renal impairment and normal renal function. Renal vascularization was evaluated in each group and compared to controls. RESULTS: Twenty-three fetuses with urinary dilatation and seventy-three fetuses with normal renal morphology where considered for statistical analysis. Five fetuses (21,7%) developed renal impairment. VI and VFI where significantly lower in fetuses that developed renal impairment than in those with normal renal function (p=0.009 and 0.036 respectively). Depth-corrected indexes (VIDC, FIDC and VFIDC) varied with gestational age and inter-observer variability was improved when depth was taken into account. The percentage of VIDC and VFIDC of cases in relation to gestational aged matched controls were lower in fetuses that developed post-natal renal impairment than in fetuses with normal renal function. CONCLUSION: Although VI and VFI were significantly lower in fetuses that developed post-natal renal impairment, depth seemed to be an important confounding variable. Thus, VIDC and VFIDC were potentially useful in this context. However, since depth-corrected indexes are related to gestational age, nomograms are needed to further evaluate the role of these parameters in predicting renal impairment

The projects of this thesis examine the complex interaction between isotonic exercise, functional capacity, exercise-induced myocardial ischaemia, severity of regurgitation and left ventricular function in patients with significant chronic mitral regurgitation. The concept of left ventricular contractile reserve, i.e. the ability of the left ventricle to increase its contractility and decrease its end systolic volume with isotonic exercise, is explored. In patients with chronic isolated mitral regurgitation without coronary disease, isotonic exercise was associated with a slight decrease in left ventricular end diastolic volume but a marked decrease in end systolic volume, resulting in a significant increase in the stroke volume and ejection fraction. Early after uncomplicated mitral valve repair surgery, there was a significant decrease in the left ventricular ejection fraction with a proportion of the patients developing left ventricular dysfunction despite a normal pre-operative ejection fraction. When different pre-operative echocardiographic indices of left ventricular function were evaluated for their ability to predict left ventricular function after mitral valve repair, the exercise indices were found to be superior to resting indices. Left ventricular end systolic volume immediately after exercise was found to be the best predictor. The optimal cut-off was at 25 ml/m2, which had a sensitivity and specificity of 83% in predicting early post-operative left ventricular dysfunction. Exercise indices appeared to be superior to resting indices in identifying patients with persistent left ventricular dysfunction &lt1 year after mitral valve repair. The concept of contractile reserve was further examined by estimating the left ventricular stroke work from simplified pressure-volume loops, which were constructed from non-invasively obtained parameters with geometric assumptions. Left ventricular stroke work immediately after exercise, but not at rest, was found to be significantly lower in patients with latent left ventricular dysfunction. Patients without latent ventricular dysfunction had similar increases in stroke work with exercise compared with healthy normal subjects. The ability of the left ventricle to increase its stroke work with exercise, a measure of the contractile reserve, was correlated with the left ventricular ejection fraction after mitral valve repair. A numerical model was constructed using the clinical data as input parameters. The results from the numerical model were similar to that obtained from the clinical study, testifying that the observation made in the clinical study was valid and independent of the geometric assumptions made in constructing the simplified pressure-volume loops. Left ventricular pressure-volume loops under different loading conditions were plotted from simultaneously measured left ventricular pressure and volume to measure the left ventricular end systolic elastance (Ees) and preload recruitable stroke work relationship (MSW). Despite normal or near normal haemodynamics at rest, a significant proportion of the study patients were found to have impaired left ventricular contractility, as measured by Ees, consistent with a state of latent left ventricular dysfunction. Exercise indices of left ventricular function were better correlated with Ees and MSW than resting indices. There were highly significant inverse relationships between end systolic volume index immediately after exercise and Ees and MSW. Moreover, there was a significant powered relationship between MSW and exercise left ventricular ejection fraction. There was no such relationship between Ees or MSW and any of the resting echocardiographic indices of left ventricular function. Furthermore, the optimal diagnostic cut-off level of end systolic volume index after exercise at 25 ml/m2 accurately identified those with impaired left ventricular contractility as defined by an Ees of &gt 2 mmHg/ml. In patients with chronic organic mitral regurgitation with ejection fraction of &lt 50%, objectively measured functional capacity, VO2max, was correlated with exercise cardiac output, patient age and gender but not to the severity of the mitral regurgitation or the resting left ventricular function. The VO2max of these patients were significantly lower than that of age and gender-matched healthy controls despite these patients' relative lack of subjective symptoms. There were significant individual variations in the response of the severity of the mitral regurgitation to isotonic exercise. Patients whose regurgitant stroke volume increased had a lower exercise cardiac output than those whose regurgitant stroke volume decreased. Such variability was also seen with the response of the left ventricular function to exercise. Patients whose left ventricular end systolic volume increased with exercise, i.e. patients with a limited contractile reserve, had a lower exercise cardiac output and lower VO2max than those whose end systolic volume decreased with exercise. The determinants of exercise capacity were then examined in patients with functional mitral regurgitation and left ventricular dysfunction. VO2max of these patients was correlated with exercise cardiac output and exercise left ventricular ejection fraction, a situation similar to that seen in patients with organic mitral regurgitation and normal left ventricular function. Furthermore, indices of left ventricular systolic function at rest and pulsed wave Doppler indices of diastolic function showed no significant correlations with VO2max. The determinants of VO2max remained unchanged in these patients after four weeks of supervised exercise training. The four weeks of exercise training resulted in a significant decrease in left ventricular end systolic volume, a trend towards an increase in left ventricular ejection fraction and some restoration of the contractile reserve. The total exercise time almost doubled. However, this dramatic improvement in total exercise time was accompanied only by non-significant increases in VO2max and left ventricular ejection fraction. Therefore, the benefits of exercise training in these patients may involve more than just central mechanisms. Exercise induced myocardial ischaemia may also contribute to a limited left ventricular contractile reserve in patients with mitral regurgitation. Electrocardiographic changes at rest are commonly seen in patients with mitral regurgitation due to mitral valve prolapse. These resting electrocardiographic changes make exercise electrocardiography uninterpretable for exercise-induced ischaemia. Exercise electrocardiographic changes are also commonly encountered in these patients despite the absence of coronary artery disease and a normal resting electrocardiogram, making exercise electrocardiography unreliable as a non-invasive screening test for coronary artery disease. In these patients, exercise echocardiography was slightly more sensitive but significantly more specific in diagnosing significant coronary artery disease. The overall accuracy and the positive predictive value were significantly higher for exercise echocardiography than for exercise electrocardiography. The &quotcost-effectiveness&quot of different diagnostic strategies for coronary artery disease in patients with mitral valve prolapse was examined based on the results of the clinical study. Strategies involving exercise electrocardiography as part of the screening test were costly and were associated with a high false negative rate. Strategies involving exercise echocardiography were more accurate and less costly but the initial costs of exercise echocardiography for all patients meant that the overall costs were still considerable. Assessing the pre-test probability of coronary artery disease in these patients and using exercise echocardiography as the initial test for patients with at least a moderate pre-test probability of coronary artery disease seemed to result in the best compromise between cost and effectiveness. The studies of this thesis have shown that a limited cardiac contractile reserve is a sign of latent ventricular dysfunction in patients with chronic mitral regurgitation. The presence of a limited contractile reserve can be used to predict left ventricular dysfunction after mitral valve repair. The concept of a limited contractile reserve is further supported by the finding of a limited increase in left ventricular stroke work with exercise from a theoretical as well as a numerical model of left ventricular pressure-volume loops. Exercise echocardiographic indices show better correlations to invasively measured Ees and MSW than resting indices. VO2max in these patients is determined more by their ability to increase their forward cardiac output with exercise and not by the regurgitant volumes. Exercise training in patients with left ventricular dysfunction and functional mitral regurgitation results in some restoration of contractile reserve. Exercise echocardiography is also a reliable and cost-effective test in the non-invasive screening for coronary artery disease in these patients. Based on the results of the studies in the thesis, one can incorporate exercise echocardiography as one of the important assessment tools in the management of patients with significant mitral regurgitation as it allows measurement of left ventricular volumes and assessment of contractile reserve. Further studies are needed to examine whether a policy of monitoring of contractile reserve in these patients to guide therapy and surgical referral will result in a better preservation of long term left ventricular function, an improvement in functional capacity and patient outcome.

Thesis (Ph.D.)--Flinders University, Faculty of Medicine, Dept. of Human Physiology. / Typescript bound. Includes bibliographical references: (leaves 332-374) Also available online via the Web.

Thesis (Ph. D.)--University of Nevada, Reno, 2002. / Includes bibliographical references. Online version available on the World Wide Web.

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Made available in DSpace on 2014-06-11T19:23:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-17Bitstream added on 2014-06-13T18:50:51Z : No. of bitstreams: 1 piratelli_cm_me_arafcf.pdf: 1575250 bytes, checksum: d4f41ac2cdd1337d9c795186663f735d (MD5) / Universidade Estadual Paulista (UNESP) / Insuficiência Renal Crônica (IRC) é o quadro clínico decorrente da perda progressiva e irreversível da função renal. Pacientes com IRC em hemodiálise apresentam uma alta prevalência de desnutrição protéico-energética caracterizada por alterações nas proteínas séricas e desequilíbrio nos compartimentos protéico e adiposo do organismo. A desnutrição, associada à piora da capacidade funcional e ao pior prognóstico de morbi-mortalidade resultam em aumento significativo nos gastos com saúde. Apesar disso, não existe ainda um método uniforme para avaliar o estado nutricional destes pacientes e o que se recomenda hoje é a aplicação de um conjunto de métodos subjetivos, antropométricos e bioquímicos para se chegar aos diagnósticos nutricionais adequados. O objetivo deste estudo foi traçar o perfil nutricional de uma população submetida à hemodiálise crônica no município de Araraquara (n=48) por meio da Avaliação Subjetiva Global modificada (ASG m), antropometria e exames bioquímicos verificando a correlação entre eles. A freqüência de desnutrição moderada e grave variou de 22 a 54%, de acordo com o parâmetro utilizado. As correlações mais significativas foram observadas entre índice de massa corporal (IMC) e adequações de prega triciptal (PCT), circunferência do braço (CB) e circunferência muscular do braço (CMB); e entre a ASGm e adequações de CB e CMB. O consumo alimentar não foi avaliado neste estudo. O acompanhamento nutricional de rotina e a validação de métodos que estudem a composição corporal de pacientes renais em hemodiálise são de extrema importância para diagnosticar precocemente a desnutrição, prevenir complicações e reduzir as taxas de morbimortalidade associadas ao estado nutricional deste paciente. / Chronic Renal Failure (CRF) is a secondary syndrome that happens when kidneys stop working. The prevalence of protein-energy malnutrition in hemodialysis patients is high and characterized by plasma proteins abnormalities and an unbalance between protein and fat body compartments. Malnutrition plus functional incompetence and worsening clinical outcome may play a role in financial public health in this population. Despite of that, there isn’t yet a uniform technique to evaluate the nutritional status of hemodialysis patients and what is recommended is a subjective and objective tool set to assess the real nutritional status of the patients. The aim of this study was to draw the nutritional profile of patients undergoing chronic hemodialysis in Araraquara city, by using the modified Subjective Global Assessment, anthropometric and biochemical data, as well as checking the correlations between them. The prevalence of moderate and severe malnutrition was variable from 22 to 54%, accordingly the criteria used. The most important correlation was between body mass index (BMI) and percentage of fit of triceps skin fold (TSF), arm circumference (AC) and arm-muscle circumference (AMC); and between modified SGA and percentage of fit of AC and AMC. The food consumption was not the aim of this work. The nutritional evaluation and analysis of body composition in chronic renal failure patients on hemodialysis is of paramount importance for an adequate clinical and nutritional intervention and to reduce the elevated mortality rate in this population.

Orientador: Rodolpho Telarolli Junior / Banca: Rodolpho Telarolli Junior / Banca: Maria Rita Brancini de Oliveira / Banca: Osvaldo Merege Vieira Neto / Resumo: Insuficiência Renal Crônica (IRC) é o quadro clínico decorrente da perda progressiva e irreversível da função renal. Pacientes com IRC em hemodiálise apresentam uma alta prevalência de desnutrição protéico-energética caracterizada por alterações nas proteínas séricas e desequilíbrio nos compartimentos protéico e adiposo do organismo. A desnutrição, associada à piora da capacidade funcional e ao pior prognóstico de morbi-mortalidade resultam em aumento significativo nos gastos com saúde. Apesar disso, não existe ainda um método uniforme para avaliar o estado nutricional destes pacientes e o que se recomenda hoje é a aplicação de um conjunto de métodos subjetivos, antropométricos e bioquímicos para se chegar aos diagnósticos nutricionais adequados. O objetivo deste estudo foi traçar o perfil nutricional de uma população submetida à hemodiálise crônica no município de Araraquara (n=48) por meio da Avaliação Subjetiva Global modificada (ASG m), antropometria e exames bioquímicos verificando a correlação entre eles. A freqüência de desnutrição moderada e grave variou de 22 a 54%, de acordo com o parâmetro utilizado. As correlações mais significativas foram observadas entre índice de massa corporal (IMC) e adequações de prega triciptal (PCT), circunferência do braço (CB) e circunferência muscular do braço (CMB); e entre a ASGm e adequações de CB e CMB. O consumo alimentar não foi avaliado neste estudo. O acompanhamento nutricional de rotina e a validação de métodos que estudem a composição corporal de pacientes renais em hemodiálise são de extrema importância para diagnosticar precocemente a desnutrição, prevenir complicações e reduzir as taxas de morbimortalidade associadas ao estado nutricional deste paciente. / Abstract: Chronic Renal Failure (CRF) is a secondary syndrome that happens when kidneys stop working. The prevalence of protein-energy malnutrition in hemodialysis patients is high and characterized by plasma proteins abnormalities and an unbalance between protein and fat body compartments. Malnutrition plus functional incompetence and worsening clinical outcome may play a role in financial public health in this population. Despite of that, there isn't yet a uniform technique to evaluate the nutritional status of hemodialysis patients and what is recommended is a subjective and objective tool set to assess the real nutritional status of the patients. The aim of this study was to draw the nutritional profile of patients undergoing chronic hemodialysis in Araraquara city, by using the modified Subjective Global Assessment, anthropometric and biochemical data, as well as checking the correlations between them. The prevalence of moderate and severe malnutrition was variable from 22 to 54%, accordingly the criteria used. The most important correlation was between body mass index (BMI) and percentage of fit of triceps skin fold (TSF), arm circumference (AC) and arm-muscle circumference (AMC); and between modified SGA and percentage of fit of AC and AMC. The food consumption was not the aim of this work. The nutritional evaluation and analysis of body composition in chronic renal failure patients on hemodialysis is of paramount importance for an adequate clinical and nutritional intervention and to reduce the elevated mortality rate in this population. / Mestre

Made available in DSpace on 2014-06-11T19:25:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-26Bitstream added on 2014-06-13T20:14:18Z : No. of bitstreams: 1 lima_df_me_botfm.pdf: 419278 bytes, checksum: 677dde7aa062755eb6e9f71846ebfbc7 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Introdução: A fase avançada de pneumopatias, cardiopatias e doenças sistêmicas está associada com o desenvolvimento de insuficiência respiratória crônica (IRespC). O tratamento desta complicação inclui o uso de oxigenoterapia domiciliar prolongada. Na literatura nacional poucos estudos avaliaram a sobrevida em pacientes com doença pulmonar obstrutiva crônica (DPOC) ou com IRespC recebendo oxigenoterapia domiciliar prolongada (ODP). Objetivo: O objetivo deste estudo foi avaliar os fatores de predição de mortalidade em pacientes com IRespC tratados com ODP no período de um, dois e três anos. Pacientes e Métodos: Foram avaliados e acompanhados pelo período mínimo de três anos ou até o óbito, 142 pacientes cadastrados no ambulatório de oxigenoterapia da Faculdade de Medicina de Botucatu (FMB) até julho de 2005. Na avaliação inicial, foram coletados dados de identificação pessoal, história de tabagismo, o uso de medicação, composição corporal, força de preensão manual, função pulmonar, gases sanguíneos e hemograma. Também foram aplicados a escala de dispnéia de Borg, o índice de dispnéia basal (BDI) e o questionário de qualidade de vida na doença respiratória do Hospital Saint George (SGRQ). Resultados: Durante os três anos de estudo; 83 pacientes (58%) morreram: 37 (26%) durante o primeiro ano de acompanhamento, 23 (16%) no segundo ano e 23 (16%) no período de três anos. O grupo óbito apresentou valores de hematócrito e hemoglobina significativamente menores, maior sensação de dispnéia, avaliada pelo BDI e Borg, e apresentou maior 18 comprometimento do estado de saúde, avaliado pelos domínios, impacto, atividade e total do SGRQ. Os principais preditores de mortalidade, na avaliação que incluía todos os pacientes, no período de três anos foram: gênero masculino (HR=2,67, CI=1,15-6,18, p=0,02), menores valores de hemoglobina... / Introduction: The advanced stage of lung, heart and systemic diseases is associated with the development of chronic respiratory failure (CRF). The treatment of this complication includes the use of long term oxygen therapy (LTOT). In the national literature few studies have assessed the survival of patients with chronic obstructive pulmonary disease (COPD) or with chronic respiratory failure treated with LTOT. Aim: The aim of this study was to evaluate the predictors of mortality in patients with CRF treated with oxygen in the period of one, two and three years. Patients and Methods: One hundred forty two patients were evaluated and followed for the minimum period of three years or until death. The study group consisted of patients with CRF, clinically stable, seen at the Oxygen Therapy Outpatient Clinic of Botucatu School of Medicine Hospital. Information about the demographic characteristics, smoking history, comorbidity conditions and treatment were collected during the first visit; evaluation of body composition, handgrip strength, lung function and blood gases and blood counts were also undertaken at this time. In addition, the dyspnea sensation (basal dyspnea index - BDI - and Borg scale) and health related quality of life (Saint George Respiratory Questionnaire) scores were calculated. Results: During the follow-up, 83 (58%) patients died; 37 (26%) during the first year of follow-up, 23 (16%) in the second year and 23 (16%) considering in three years. The group of death showed significantly lower 20 hematocrit and hemoglobin, increased sensation of breathlessness, measured by BDI and Borg, and showed greater impairment of health status as measured by impact, activity and total score of SGRQ. The main predictors of mortality, after three years of follow-up were male gender (HR=2.67, CI=1.15-6.18, p=0.02), lower values of hemoglobin (HR=0.85, CI=0.74-0.98, p=0.02), and PaCO2... (Complete abstract click electronic access below)

Made available in DSpace on 2016-07-01T13:10:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-09-12. Added 1 bitstream(s) on 2016-07-01T13:14:12Z : No. of bitstreams: 1 000866809.pdf: 1747343 bytes, checksum: 1bd62536c1ab61130611dd2e937d842f (MD5) / Os mecanismos envolvidos na remodelação cardíaca por sobrecarga de volume e o momento que a hipertrofia excêntrica apresenta prejuízo da função cardíaca são pouco conhecidos. Objetivos: a) Comparar alterações morfofuncionais, celulares (hipertrofia) e intersticiais (fibrose) em diferentes momentos da evolução da insuficiência aórtica; b) Verificar quais dos seguintes mecanismos estão envolvidos na remodelação cardíaca induzida pela IAo e em qual momento esta alteração acontece: alteração na metaloprotease 2 (MMP2) e do inibidor tecidual de metaloprotease 1 (TIMP1), alterações dos RNAs mensageiros específicos para a codificação das proteínas envolvidas na homeostase do cálcio (Fosfolambam, Ryr e Serca2a), alterações da expressão de proteínas fosfolambam e Serca2a do trânsito de cálcio. Casuística e Métodos: Estudo experimental com 64 ratos Wistar machos, 32 animais submetidos à insuficiência aórtica aguda (grupo IAo) e 32 animais a procedimento simulado (grupo Controle). Todos os animais foram seguidos com 1, 4, 8 e 12 semanas através de ecocardiogramas seriados e, após eutanásia, foram analisada morfometria do tecido cardíaco, atividade da MMP2 e TIMP-1, expressão gênica por Reação em Cadeia da Polimerase em Tempo Real das proteínas do trânsito de cálcio, expressão das proteínas Serca2a e fosfolambam pela técnica Western Blot. A análise estatística foi efetuada pela ANOVA de dois fatores; o pós teste de Holm Sidak; teste t grupo a grupo; Anova de 1 via, complementada por Tukey; correção por Bonferroni; teste de correlação de Spearman e teste de correlação de Pearson. Em todos os casos, o nível de significância adotado foi p<0,05. Resultados: Observou-se, na primeira semana, que o peso do VE e a pressão diastólica foi maior no grupo IAo. Na quarta semana, MMP2, TIMP-1, iMVE e fração de colágeno foram maiores no grupo IAo. A área do miócito e DDVE foram maiores... / The mechanisms that are involved in cardiac remodeling by volume overload and the moment the eccentric hypertrophy has impaired cardiac function are largely unknown. Objectives: a) to compare morphological, cell (hypertrophy) and interstitial (fibrosis) changes at different times of the evolution of aortic regurgitation (AR); b) to analyze which of the following mechanisms are involved in cardiac remodeling induced by aortic failure and at what moment this change takes place: change in the metalloprotease 2 (MMP 2) and tissue inhibitor of metalloproteinase 1 (TIMP1); changes of messenger RNAs to code proteins involved in calcium homeostasis (phospholamban, Ryr and SERCA2a), changes in expression of phospholamban and SERCA2a in the calcium transit. Methods: Experimental study with 64 male Wistar rats, 32 animals submitted to acute aortic regurgitation (AR group) and 32 animals sham procedure (Sham group). All animals were followed with 1, 4, 8 and 12 weeks by serial echocardiography and after euthanasia, were analyzed morphometry of cardiac tissue, the activity of MMP2 and TIMP-1, gene expression by RT-PCR of calcium homeostasis protein, SERCA2a and phospholamban expression by Western Blotting. Statistical analysis was performed by two-way ANOVA; the Holm Sidak post test; t test group to group; Anova one way, complemented by Tukey; Bonferroni correction; Spearman correlation test and Pearson's correlation test. In all cases, the significance level was set at p <0.05. Results: In the first week it was observed that weight of the LV and diastolic blood pressure were higher in the AR group. In the fourth week, MMP 2, TIMP-1, and collagen fraction were higher in the AR group. The myocyte area and left ventricle diastolic diameter (LVDD) were higher in the AR group compared to the sham group, from the eighth week. At weeks 8 and 12, the wall thickness (WT) was higher in the AR group than the...