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Development and Testing of a Nurse Practitioner Secondary Prevention Intervention for Patients after Acute Myocardial InfarctionHarbman, Patricia 09 January 2012 (has links)
Patients with acute myocardial infarction (AMI) are at high risk for reinfarction and death, with the highest rate of death and reinfarction occurring within 30 days of AMI. Therapies that have been shown to reduce these risks (secondary prevention) continue to be underutilized. Nurse practitioners are well positioned to provide secondary prevention during and following hospitalization. The purpose of this pilot study was to examine the feasibility, acceptability, and preliminary effects of an NP delivered secondary prevention intervention. The specific objectives were: 1) to describe NP activities when delivering the secondary prevention intervention; 2) to evaluate the effect of the NP intervention on the rate of implementation of evidence-based secondary prevention treatment strategies and the patients’ achievement of secondary prevention target goals; and, 3) to examine the relationship between the NP activities delivering the intervention and secondary prevention goal achievement by patients.
A prospective cohort design was used, in which patients’ achievement of target goals were compared between patients who received secondary prevention care from an NP and those who received usual care. The sample of convenience consisted of 65 patients with AMI. Data on practice activities and implementation of secondary prevention by the NP were collected before discharge from hospital and one week, two weeks, six weeks and 3 months after discharge. Data on patients’ achievement of goals were obtained before discharge from hospital and 3 months after discharge from both groups. This study’s results provide preliminary evidence that an NP delivered secondary prevention intervention, beginning prior to discharge and continuing for three months post myocardial infarction, significantly improves the implementation and uptake of guideline based secondary prevention treatments and risk factor reduction strategies. NP-led interventions such as this warrant replication. The unique contribution of the NP with this patient population is the training and skills needed to deliver all aspects of secondary prevention, including pharmacological and nonpharmacological therapies, without the immediate availability of a physician.
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When time matters : Patients’ and spouses’ experiences of suspected acute myocardial infarction in the pre-hospital phaseJohansson, Ingela January 2006 (has links)
The overall aim of this thesis was to describe patients’ and spouses’ experiences of suspected acute myocardial infarction in the pre-hospital phase. A descriptive survey study was conducted to identify various factors influencing patient delay in 381 patients with suspected myocardial infarction hospitalised at a Coronary Care Unit (I) and ambulance utilisation among 110 myocardial infarction patients (II). In order to obtain a deeper understanding of the myocardial infarction patients’ own conceptions about the event, an interview study with a phenomenographic approach was conducted with 15 strategically selected myocardial infarction patients (III), within 72 hours after admission to hospital. Finally, the pre-hospital experiences of 15 spouses of myocardial infarction patients were also studied through interviews with a phenomenographic approach, within 48 hours after the affected partner’s admittance to hospital (IV). The results showed that 59% of the patients with suspected acute myocardial infarction delayed > 1 hour after onset of symptoms. The most common reasons given for delay in seeking hospital admittance were: (1) Did not consider the symptoms as to be severe enough that they warranted hospital care, (2) thought the symptoms to be temporary and that they would disappear, (3) the chest pain was more of a dull pain, (4) or, as one third of the patients chose to do, contacted the general practitioner instead of going directly to the hospital (I). Furthermore, as a first action, 59% consulted their spouse for advice about what to do henceforth. The most common reason for additional delay when the decision to go to hospital had already been taken was that the myocardial infarction patients stated that they were unaware of the advantages of a rapid decision-making process. Sixty percent went by ambulance, but it was the spouse (40%) or the personnel at the general practitioner’s office (32%) who called the emergency service number, rather than the patient him/her self (5%). The most frequently given reasons for not choosing ambulance, were that the patients did not perceive their symptoms as being serious enough to require ambulance transportation (43%), followed by that they had not thought about ambulance as an alternative at all (38%). As a third reason for not going by ambulance, the patients stated that it was unnecessary to call an ambulance when being affected by symptoms related to a myocardial infarction (26%). The patients who called an ambulance differed in some respects from those who went by private alternatives; patients with large infarctions (ST-Elevation Myocardial Infarction) went by ambulance more frequently, as did patients suffering from nausea and severe chest pain (II). The patients expressed in the interviews how the interaction with others, described as the need for supportive environment, worries for the family and the utilisation of the health-care resources, was of great importance in the pre-hospital phase. Likewise, symptom awareness, with earlier experiences of a similar situation to compare with, denying the seriousness of the situation and the use of different self-care strategies, were important in order to manage the situation. Vulnerability, expressed as anxiety and a lack of control, also influenced the decision-making process in the pre-hospital phase (III). Spouses seemed to have a strong influence on the course of events when their partner suffered an acute myocardial infarction and it emerged from the interviews how the spouses in many cases were influenced into sharing the denial of the affected partner by respecting his/her independence. The spouses accepted the partner’s need for control; took earlier marital roles and experiences into account; restraining own emotions and seeking agreement with their partners, contributing to delay. However, being resourceful by sharing the experience; having knowledge; understanding the severity; being rational and consulting others when needed, seemed to have a positive influence on the decision time in the pre-hospital phase (IV). Conclusion: The reasons for delaying or not in the pre-hospital phase, as well as the reasons for utilising the ambulance services or not, varied considerably between individuals. Earlier experiences of MI did not influence what actions to take; instead patients’ feelings, emotional attitudes to MI symptoms, inadequate coping strategies, and spouses’ influences were important components in the pre-hospital phase.
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Complementary role of adenosine in reducing the infarct size and preserving the left ventricular function in patients with acute myocardial infarction / Papildomas adenozino vaidmuo mažinant infarkto dydį ir išsaugant kairiojo skilvelio funkciją pacientams, sergantiems ūminiu miokardo infarktuSadauskienė, Eglė 02 November 2011 (has links)
Study evaluates adenosine, which is used as an adjunct to conventional reperfusion therapy (percutaneous coronary intervention, i.e. PCI), role in reducing the infarct size and preserving the left ventricular function in patients with acute myocardial infarction. During the study we examined patients with the left ventricular anterior wall acute myocardial infarction (AMI), when PCI and stenting were used for infarct-related artery (IRA) re-opening. Study evaluates influence of complementary use of adenosine in reducing the myocardial ischemic-reperfusion injury, the manifestation of slow-reflow or no-reflow phenomenon. The results of reperfusion therapy with adjunctive adenosine and without adenosine were analyzed in two homogeneous patient groups. By using new non-invasive imaging methods (single photon emission computer tomography, transthoracic Doppler echocardiography, dobutamine stress echocardiography) it was estimated, that adenosine preserves myocardial contractility and coronary flow reserve during the acute phase of myocardial infarction, reduces the final infarct size, improves the recovery of left ventricular global and segmental contractile function at five months follow-up. Those results are achieved due to adenosine impact on improving blood flow restoration not only in major coronary arteries, but also at microcirculatory level and ensuring of adequate and effective myocardial reperfusion. / Tyrime analizuojama adenozino, kuriuo papildoma įprastinė reperfuzinė terapija (perkutaninė koronarinė intervencija), įtaka mažinant infarkto dydį ir išsaugant kairiojo skilvelio funkciją pacientams, sergantiems ūminiu miokardo infarktu. Tyrimo metu siekta įvertinti PKI ir stentavimo būdu atveriant priekinės nusileidžiančios šakos spindį, kurio okliuzija sąlygojo kairiojo skilvelio priekinės sienelės ūminį miokardo infarktą, papildomai naudojamo adenozino įtaką mažinant miokardo išeminį-reperfuzinį pažeidimą, lėtos ar nutrūkusios tėkmės fenomeno pasireiškimą ir išplitimą. Reperfuzinės terapijos (PKI naudojant adenoziną ir PKI be adenozino) rezultatų ypatumai ir skirtumai palyginti dviejose homogeniškose pagal kontrolinius kintamuosius pacientų grupėse. Pasitelkus naujausius neinvazinius vaizdinimo metodus (miokardo perfuzijos radionuklidinę kompiuterinę tomografiją, transtorakalinę doplerinę echokardiografiją, dobutamino krūvio echokardiografiją) nustatyta, kad adenozinas, gerindamas kraujo tėkmės atstatymą ne tik stambiosiose vainikinėse arterijose, bet ir mikrocirkuliacijos grandyje, užtikrindamas adekvačią bei efektyvią miokardo reperfuziją, išsaugo miokardo kontraktilinį bei koronarinės tėkmės rezervus ūminio miokardo infarkto metu, mažina galutinį infarkto dydį, gerina bendrosios ir segmentinės kairiojo skilvelio kontraktilinės funkcijos atsistatymą praėjus 5 mėn. po reperfuzinio miokardo infarkto gydymo.
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Papildomas adenozino vaidmuo mažinant infarkto dydį ir išsaugant kairiojo skilvelio funkciją pacientams, sergantiems ūminiu miokardo infarktu / Complementary role of adenosine in reducing the infarct size and preserving the left ventricular function in patients with acute myocardial infarctionSadauskienė, Eglė 02 November 2011 (has links)
Tyrime analizuojama adenozino, kuriuo papildoma įprastinė reperfuzinė terapija (perkutaninė koronarinė intervencija), įtaka mažinant infarkto dydį ir išsaugant kairiojo skilvelio funkciją pacientams, sergantiems ūminiu miokardo infarktu. Tyrimo metu siekta įvertinti PKI ir stentavimo būdu atveriant priekinės nusileidžiančios šakos spindį, kurio okliuzija sąlygojo kairiojo skilvelio priekinės sienelės ūminį miokardo infarktą, papildomai naudojamo adenozino įtaką mažinant miokardo išeminį-reperfuzinį pažeidimą, lėtos ar nutrūkusios tėkmės fenomeno pasireiškimą ir išplitimą. Reperfuzinės terapijos (PKI naudojant adenoziną ir PKI be adenozino) rezultatų ypatumai ir skirtumai palyginti dviejose homogeniškose pagal kontrolinius kintamuosius pacientų grupėse. Pasitelkus naujausius neinvazinius vaizdinimo metodus (miokardo perfuzijos radionuklidinę kompiuterinę tomografiją, transtorakalinę doplerinę echokardiografiją, dobutamino krūvio echokardiografiją) nustatyta, kad adenozinas, gerindamas kraujo tėkmės atstatymą ne tik stambiosiose vainikinėse arterijose, bet ir mikrocirkuliacijos grandyje, užtikrindamas adekvačią bei efektyvią miokardo reperfuziją, išsaugo miokardo kontraktilinį bei koronarinės tėkmės rezervus ūminio miokardo infarkto metu, mažina galutinį infarkto dydį, gerina bendrosios ir segmentinės kairiojo skilvelio kontraktilinės funkcijos atsistatymą praėjus 5 mėn. po reperfuzinio miokardo infarkto gydymo. / Study evaluates adenosine, which is used as an adjunct to conventional reperfusion therapy (percutaneous coronary intervention, i.e. PCI), role in reducing the infarct size and preserving the left ventricular function in patients with acute myocardial infarction. During the study we examined patients with the left ventricular anterior wall acute myocardial infarction (AMI), when PCI and stenting were used for infarct-related artery (IRA) re-opening. Study evaluates influence of complementary use of adenosine in reducing the myocardial ischemic-reperfusion injury, the manifestation of slow-reflow or no-reflow phenomenon. The results of reperfusion therapy with adjunctive adenosine and without adenosine were analyzed in two homogeneous patient groups. By using new non-invasive imaging methods (single photon emission computer tomography, transthoracic Doppler echocardiography, dobutamine stress echocardiography) it was estimated, that adenosine preserves myocardial contractility and coronary flow reserve during the acute phase of myocardial infarction, reduces the final infarct size, improves the recovery of left ventricular global and segmental contractile function at five months follow-up. Those results are achieved due to adenosine impact on improving blood flow restoration not only in major coronary arteries, but also at microcirculatory level and ensuring of adequate and effective myocardial reperfusion.
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Efeitos do tratamento com tiroxina no remodelamento cardíaco pós-infarto agudo do miocárdio e em parâmetros de estresse oxidativoBerger, Bruno da Rocha January 2012 (has links)
O infarto agudo do miocárdio (IAM) é um evento que acomete milhares de pessoas ao redor do mundo. Após o IAM são desencadeados diversos processos, como alterações na expressão de proteínas envolvidas na contratilidade cardíaca e no remodelamento cardíaco após o IAM, bem como o desequilíbrio no estado redox da célula, que podem levar a um grave prognóstico. A utilização dos hormônios da tireoide vem sendo amplamente estudada na tentativa de desenvolver um método terapêutico eficiente para o tratamento do IAM. Desta forma, o objetivo deste estudo foi verificar os efeitos da tiroxina (T4) sobre a expressão e a concentração de antioxidantes e pró-oxidantes e sobre a expressão de proteínas relacionadas ao metabolismo do cálcio, e suas possíveis relações com a melhora na função cardíaca após o IAM. Foram utilizados ratos Wistar, divididos nos seguintes grupos experimentais: SHAM, infartado (IAM) e infartado e tratado com T4 nas doses de 1,2, 2,4 e 6,0 mg/L de água de beber. O tratamento foi iniciado 24 horas após a indução do IAM e após 14 dias foram coletados dados morfométricos e ecocardiográficos, além de analisadas as expressões das proteínas cálcio ATPase do retículo sarcoplasmático (SERCA2a), fosfolambam (PLB), fator nuclear eritroide do tipo 2 (Nrf2) e hemeoxigenase 1 (HO-1). Também foram quantificadas as concentrações de peróxido de hidrogênio (H2O2) e de glutationa total em homogeneizado de tecido cardíaco. Os animais infartados, tratados ou não, apresentaram hipertrofia cardíaca independente da dose do tratamento. O IAM provocou uma redução da função cardíaca, e o tratamento com T4 não foi capaz de reverter esses efeitos. A expressão das proteínas PLB e Nrf2 diminuiu após o IAM. Os animais tratados com T4 em suas doses mais altas apresentaram valores da expressão da proteína Nrf2 semelhantes aos animais do grupo SHAM. Os grupos infartado e tratado com T4 nas doses de 2,4 e 6,0 mg/L apresentaram valores de expressão da SERCA2a maiores quando comparados com o grupo SHAM. As concentrações de H2O2 e de glutationa total não foram alteradas após o IAM, e o tratamento com T4 também não alterou estes parâmetros. Em suma, uma vez que a dose de T4 de 6,0 mg/L modulou a expressão do Nrf2, uma proteína importante para o estado redox da célula, sugerimos que poderia estar ocorrendo uma adaptação de sistemas antioxidantes distintos dos analisados neste estudo e que também são regulados por este fator de transcrição. / The acute myocardial infarction (AMI) is an event that affects thousands of people around the world. After AMI are triggered several processes, such as changes in expression of proteins involved in cardiac contractility and cardiac remodeling, as well as the cell redox state imbalance, which can lead to serious prognosis. The use of thyroid hormones has been widely studied in an attempt to develop an efficient therapeutic method for treatment of AMI. Thus, the objective of this study was to investigate the effects of thyroxine (T4) on expression and concentration of antioxidant and pro-oxidants and the expression of proteins related to calcium metabolism, and their possible relationships with improvement in cardiac function after AMI. Wistar rats were divided into the following groups: SHAM, myocardial infarction (AMI) and myocardial infarction and treated with T4 at doses of 1,2, 2,4 and 6,0 mg / L of drinking water. Treatment was initiated 24 hours after induction of AMI and after 14 days were collected morphometric and echocardiographic data, and analyzed protein expression of sarcoplasmic reticulum calcium ATPase (SERCA2a), phospholamban (PLB), nuclear factor erythroid type 2 (Nrf2) and hemeoxygenase 1 (HO-1). Also were quantitated concentrations of hydrogen peroxide (H2O2) and total glutathione in homogenized of cardiac tissue. The infarcted animals, treated or not, showed cardiac hypertrophy, independent of the dose of treatment. The AMI has caused a decline in cardiac function parameters, and treatment with T4 was not able to reverse these effects. The protein expression of PLB and Nrf2 decreased after AMI. Animals treated with T4 in their higher doses had values of Nrf2 protein expression similar to those animals of the SHAM group. The infarcted groups and treated with T4 at doses of 2.4 and 6.0 mg / L had higher SERCA2a expression when compared to the sham group. The concentrations of H2O2 and total glutathione were not altered after AMI, and treatment with T4 did not alter these parameters. In short, since the treatment dose of 6.0 mg / L modulates the expression of Nrf2, an important protein for the redox state of the cell, we suggest what might be going on an adaptation of antioxidant systems distinct from those analyzed in this study and are also regulated by this transcription factor.
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Avaliação dos efeitos da co-administração dos hormônios da tireoide e do carvedilol sobre o coração de ratos Wistar submetidos ao infarto agudo do miocárdioOrtiz, Vanessa Duarte January 2018 (has links)
Introdução: Após o infarto agudo do miocárdio (IAM), o tratamento com hormônios da tireoide (HT) vem revelando efeitos cardioprotetores. Os HT, todavia, provocam uma estimulação adrenérgica, induzindo elevação da frequência cardíaca, a qual contribui para progressão da disfunção ventricular após o IAM. O betabloqueador carvedilol, entretanto, é capaz de bloquear a estimulação adrenérgica. Objetivo: Avaliar o efeito da administração conjunta dos HT e do carvedilol sobre o coração de ratos submetidos ao IAM. Nesse contexto, enfocar nos efeitos dessa coadministração sobre o remodelamento ventricular, a função cardíaca e o estresse oxidativo. Materiais e métodos: Ratos Wistar machos foram divididos em cinco grupos (n=8-10/grupo): grupo sham (SHAM), grupo infarto (IM), grupo infarto+HT (IM+HT), grupo infarto+carvedilol (IM+C) e grupo infarto+C+HT (IM+C+HT). Após o IAM, os grupos SHAM e IM receberam salina, e os tratados receberam seus respectivos tratamentos por 12 dias por gavage. Após esse período, os animais foram submetidos a uma avaliação ecocardiográfica, e, posteriormente, ao cateterismo venticular. Em seguida, os animais foram eutanasiados para a coleta do coração, do pulmão e do fígado, para análises morfométricas e bioquímicas. Análise estatística: ANOVA de uma via seguida pelo teste de Student-Newman-Keuls. Nível de significância P<0,05. Resultados: A respeito dos parâmetros morfométricos, foi possível verificar hipertrofia cardíaca nos grupos infartados tratados em relação aos grupos SHAM e IM. Quanto aos parâmetros ecocardiográficos, os grupos tratados demonstraram aumento da espessura da parede posterior na sístole, da fração de ejeção e redução do índice de tensão de parede em comparação ao grupo IM. Os grupos IM+C e IM+C+HT também apresentaram atenuação da redução da mudança de área fracional e do aumento do volume sistólico final em relação aos grupos IM e IM+HT. Quanto aos parâmetros hemodinâmicos, houve redução das dP/dt máxima e mínima, da pressão sistólica do ventrículo esquerdo (VE) e aumento da pressão diastólica final do VE no grupo IM em comparação ao SHAM. Entretanto, todos esses parâmetros foram revertidos nos grupos tratados. A frequência cardíaca aumentou nos grupos IM+HT e IM+C+HT em relação aos outros grupos, mas reduziu no grupo IM+C+HT em relação ao grupo IM+HT. Quanto aos parâmetros de estresse oxidativo, verificou-se aumento dos níveis de espécies reativas de oxigênio (ERO) e redução dos níveis de sulfidrilas no grupo IM e IM+C em relação ao grupo SHAM, enquanto os grupos IM+HT e IM+C+HT não foram diferentes do grupo SHAM. Ainda, no grupo IM+C+HT, o co-tratamento apresentou efeito sinérgico na redução dos níveis de ERO e no aumento da razão GSH/GSSG. Conclusão: A coadminsitração do carvedilol e dos HT foi capaz de melhorar o remodelamento ventricular e a função cardíaca após o IAM. Ainda, o carvedilol foi capaz de exercer seu efeito betabloqueador no grupo IM+C+HT, uma vez que reduziu a frequência cardíaca aumentada pelos HT. Além disso, a co-administração apresentou um efeito sinérgico positivo nos parâmetros de estresse oxidativo, especificamente, sobre os níveis de ERO e o balanço redox através da razão GSH/GSSG, dessa forma preservando a homeostase redox do tecido cardíaco. / Introduction: After acute myocardial infarction (AMI), treatment with thyroid hormones (TH) has revealed cardioprotective effects. However, TH causes adrenergic stimulation, which effect increase heart rate and this may contribute to ventricular dysfunction progression after AMI. Meanwhile, the beta-blocker carvedilol is able to block adrenergic stimulation. Aim: To evaluate the effects of TH and carvedilol co-administration on the heart of rats submitted to AMI. In this context, it focused on the effects of this co-administration on ventricular remodeling, cardiac function and oxidative stress. Material and methods: Male Wistar rats were divided in five groups (n=8-10/group): sham (SHAM), infarcted (MI), infarcted+TH (MI+TH), infarcted+carvedilol (MI+C) and infarcted group+C+TH (IM+C+TH). Post-AMI, SHAM and MI groups received saline, and the treated groups received their respective treatments for 12 days by gavage. After this period, the animals were submitted to an echocardiographic evaluation and, later, to the ventricular catheterization. Afterwards, the animals were euthanized for the heart lung and liver collection, for morphometric and biochemical analyzes. Statistical Analysis: One-way ANOVA followed by Student-Newman-Keuls test. Significance level P<0,05. Results: Regarding the morphometric parameters, it was possible to verify cardiac hypertrophy in the treated infarcted groups in relation to the SHAM and MI groups, as well as there was no significant difference between the groups regarding pulmonary and hepatic congestion. In relation to echocardiographic parameters, treated groups showed an increase in systolic posterior wall thickness, ejection fraction and a reduction in wall tension index compared to MI group. MI+C and MI+C+TH groups also presented attenuation of the reduction in the fractional area change and of the increase in the final systolic volume in relation to the MI and MI+TH groups. Regarding the hemodynamic parameters, there was a reduction of the maximum and minimum dP/dt, the left ventricular (LV) systolic pressure and an increase in the final LV diastolic pressure in the MI group compared to SHAM. However, all these parameters were reversed in the treated groups. The heart rate increased in the MI+TH and MI+C+TH groups compared to the other groups, but decreased in the MI+C+TH group compared to the MI+TH group. Regarding the parameters of oxidative stress, there was an increase in the levels of reactive oxygen species (ROS) and reduction of sulfhydryl levels in the MI and MI+C groups compared to the SHAM group, while the MI+TH and MI+C groups were not different from the SHAM group. In addition, in the M+C+TH group, the co-treatment showed a synergic effect in reducing ERO levels and increasing GSH/GSSG ratio. Conclusion: Coadministration of carvedilol and TH was able to improve ventricular remodeling and cardiac function after AMI. In addition, carvedilol was able to exert its betablocking effect in the MI+C+TH group, since it reduced the heart rate increased by TH. In addition, co-administration had a positive synergistic effect on oxidative stress parameters, specifically on ROS levels and redox balance through the GSH/GSSG ratio, thus preserving redox homeostasis of cardiac tissue.
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Avaliação dos efeitos da co-administração dos hormônios da tireoide e do carvedilol sobre o coração de ratos Wistar submetidos ao infarto agudo do miocárdioOrtiz, Vanessa Duarte January 2018 (has links)
Introdução: Após o infarto agudo do miocárdio (IAM), o tratamento com hormônios da tireoide (HT) vem revelando efeitos cardioprotetores. Os HT, todavia, provocam uma estimulação adrenérgica, induzindo elevação da frequência cardíaca, a qual contribui para progressão da disfunção ventricular após o IAM. O betabloqueador carvedilol, entretanto, é capaz de bloquear a estimulação adrenérgica. Objetivo: Avaliar o efeito da administração conjunta dos HT e do carvedilol sobre o coração de ratos submetidos ao IAM. Nesse contexto, enfocar nos efeitos dessa coadministração sobre o remodelamento ventricular, a função cardíaca e o estresse oxidativo. Materiais e métodos: Ratos Wistar machos foram divididos em cinco grupos (n=8-10/grupo): grupo sham (SHAM), grupo infarto (IM), grupo infarto+HT (IM+HT), grupo infarto+carvedilol (IM+C) e grupo infarto+C+HT (IM+C+HT). Após o IAM, os grupos SHAM e IM receberam salina, e os tratados receberam seus respectivos tratamentos por 12 dias por gavage. Após esse período, os animais foram submetidos a uma avaliação ecocardiográfica, e, posteriormente, ao cateterismo venticular. Em seguida, os animais foram eutanasiados para a coleta do coração, do pulmão e do fígado, para análises morfométricas e bioquímicas. Análise estatística: ANOVA de uma via seguida pelo teste de Student-Newman-Keuls. Nível de significância P<0,05. Resultados: A respeito dos parâmetros morfométricos, foi possível verificar hipertrofia cardíaca nos grupos infartados tratados em relação aos grupos SHAM e IM. Quanto aos parâmetros ecocardiográficos, os grupos tratados demonstraram aumento da espessura da parede posterior na sístole, da fração de ejeção e redução do índice de tensão de parede em comparação ao grupo IM. Os grupos IM+C e IM+C+HT também apresentaram atenuação da redução da mudança de área fracional e do aumento do volume sistólico final em relação aos grupos IM e IM+HT. Quanto aos parâmetros hemodinâmicos, houve redução das dP/dt máxima e mínima, da pressão sistólica do ventrículo esquerdo (VE) e aumento da pressão diastólica final do VE no grupo IM em comparação ao SHAM. Entretanto, todos esses parâmetros foram revertidos nos grupos tratados. A frequência cardíaca aumentou nos grupos IM+HT e IM+C+HT em relação aos outros grupos, mas reduziu no grupo IM+C+HT em relação ao grupo IM+HT. Quanto aos parâmetros de estresse oxidativo, verificou-se aumento dos níveis de espécies reativas de oxigênio (ERO) e redução dos níveis de sulfidrilas no grupo IM e IM+C em relação ao grupo SHAM, enquanto os grupos IM+HT e IM+C+HT não foram diferentes do grupo SHAM. Ainda, no grupo IM+C+HT, o co-tratamento apresentou efeito sinérgico na redução dos níveis de ERO e no aumento da razão GSH/GSSG. Conclusão: A coadminsitração do carvedilol e dos HT foi capaz de melhorar o remodelamento ventricular e a função cardíaca após o IAM. Ainda, o carvedilol foi capaz de exercer seu efeito betabloqueador no grupo IM+C+HT, uma vez que reduziu a frequência cardíaca aumentada pelos HT. Além disso, a co-administração apresentou um efeito sinérgico positivo nos parâmetros de estresse oxidativo, especificamente, sobre os níveis de ERO e o balanço redox através da razão GSH/GSSG, dessa forma preservando a homeostase redox do tecido cardíaco. / Introduction: After acute myocardial infarction (AMI), treatment with thyroid hormones (TH) has revealed cardioprotective effects. However, TH causes adrenergic stimulation, which effect increase heart rate and this may contribute to ventricular dysfunction progression after AMI. Meanwhile, the beta-blocker carvedilol is able to block adrenergic stimulation. Aim: To evaluate the effects of TH and carvedilol co-administration on the heart of rats submitted to AMI. In this context, it focused on the effects of this co-administration on ventricular remodeling, cardiac function and oxidative stress. Material and methods: Male Wistar rats were divided in five groups (n=8-10/group): sham (SHAM), infarcted (MI), infarcted+TH (MI+TH), infarcted+carvedilol (MI+C) and infarcted group+C+TH (IM+C+TH). Post-AMI, SHAM and MI groups received saline, and the treated groups received their respective treatments for 12 days by gavage. After this period, the animals were submitted to an echocardiographic evaluation and, later, to the ventricular catheterization. Afterwards, the animals were euthanized for the heart lung and liver collection, for morphometric and biochemical analyzes. Statistical Analysis: One-way ANOVA followed by Student-Newman-Keuls test. Significance level P<0,05. Results: Regarding the morphometric parameters, it was possible to verify cardiac hypertrophy in the treated infarcted groups in relation to the SHAM and MI groups, as well as there was no significant difference between the groups regarding pulmonary and hepatic congestion. In relation to echocardiographic parameters, treated groups showed an increase in systolic posterior wall thickness, ejection fraction and a reduction in wall tension index compared to MI group. MI+C and MI+C+TH groups also presented attenuation of the reduction in the fractional area change and of the increase in the final systolic volume in relation to the MI and MI+TH groups. Regarding the hemodynamic parameters, there was a reduction of the maximum and minimum dP/dt, the left ventricular (LV) systolic pressure and an increase in the final LV diastolic pressure in the MI group compared to SHAM. However, all these parameters were reversed in the treated groups. The heart rate increased in the MI+TH and MI+C+TH groups compared to the other groups, but decreased in the MI+C+TH group compared to the MI+TH group. Regarding the parameters of oxidative stress, there was an increase in the levels of reactive oxygen species (ROS) and reduction of sulfhydryl levels in the MI and MI+C groups compared to the SHAM group, while the MI+TH and MI+C groups were not different from the SHAM group. In addition, in the M+C+TH group, the co-treatment showed a synergic effect in reducing ERO levels and increasing GSH/GSSG ratio. Conclusion: Coadministration of carvedilol and TH was able to improve ventricular remodeling and cardiac function after AMI. In addition, carvedilol was able to exert its betablocking effect in the MI+C+TH group, since it reduced the heart rate increased by TH. In addition, co-administration had a positive synergistic effect on oxidative stress parameters, specifically on ROS levels and redox balance through the GSH/GSSG ratio, thus preserving redox homeostasis of cardiac tissue.
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Efeitos do tratamento com tiroxina no remodelamento cardíaco pós-infarto agudo do miocárdio e em parâmetros de estresse oxidativoBerger, Bruno da Rocha January 2012 (has links)
O infarto agudo do miocárdio (IAM) é um evento que acomete milhares de pessoas ao redor do mundo. Após o IAM são desencadeados diversos processos, como alterações na expressão de proteínas envolvidas na contratilidade cardíaca e no remodelamento cardíaco após o IAM, bem como o desequilíbrio no estado redox da célula, que podem levar a um grave prognóstico. A utilização dos hormônios da tireoide vem sendo amplamente estudada na tentativa de desenvolver um método terapêutico eficiente para o tratamento do IAM. Desta forma, o objetivo deste estudo foi verificar os efeitos da tiroxina (T4) sobre a expressão e a concentração de antioxidantes e pró-oxidantes e sobre a expressão de proteínas relacionadas ao metabolismo do cálcio, e suas possíveis relações com a melhora na função cardíaca após o IAM. Foram utilizados ratos Wistar, divididos nos seguintes grupos experimentais: SHAM, infartado (IAM) e infartado e tratado com T4 nas doses de 1,2, 2,4 e 6,0 mg/L de água de beber. O tratamento foi iniciado 24 horas após a indução do IAM e após 14 dias foram coletados dados morfométricos e ecocardiográficos, além de analisadas as expressões das proteínas cálcio ATPase do retículo sarcoplasmático (SERCA2a), fosfolambam (PLB), fator nuclear eritroide do tipo 2 (Nrf2) e hemeoxigenase 1 (HO-1). Também foram quantificadas as concentrações de peróxido de hidrogênio (H2O2) e de glutationa total em homogeneizado de tecido cardíaco. Os animais infartados, tratados ou não, apresentaram hipertrofia cardíaca independente da dose do tratamento. O IAM provocou uma redução da função cardíaca, e o tratamento com T4 não foi capaz de reverter esses efeitos. A expressão das proteínas PLB e Nrf2 diminuiu após o IAM. Os animais tratados com T4 em suas doses mais altas apresentaram valores da expressão da proteína Nrf2 semelhantes aos animais do grupo SHAM. Os grupos infartado e tratado com T4 nas doses de 2,4 e 6,0 mg/L apresentaram valores de expressão da SERCA2a maiores quando comparados com o grupo SHAM. As concentrações de H2O2 e de glutationa total não foram alteradas após o IAM, e o tratamento com T4 também não alterou estes parâmetros. Em suma, uma vez que a dose de T4 de 6,0 mg/L modulou a expressão do Nrf2, uma proteína importante para o estado redox da célula, sugerimos que poderia estar ocorrendo uma adaptação de sistemas antioxidantes distintos dos analisados neste estudo e que também são regulados por este fator de transcrição. / The acute myocardial infarction (AMI) is an event that affects thousands of people around the world. After AMI are triggered several processes, such as changes in expression of proteins involved in cardiac contractility and cardiac remodeling, as well as the cell redox state imbalance, which can lead to serious prognosis. The use of thyroid hormones has been widely studied in an attempt to develop an efficient therapeutic method for treatment of AMI. Thus, the objective of this study was to investigate the effects of thyroxine (T4) on expression and concentration of antioxidant and pro-oxidants and the expression of proteins related to calcium metabolism, and their possible relationships with improvement in cardiac function after AMI. Wistar rats were divided into the following groups: SHAM, myocardial infarction (AMI) and myocardial infarction and treated with T4 at doses of 1,2, 2,4 and 6,0 mg / L of drinking water. Treatment was initiated 24 hours after induction of AMI and after 14 days were collected morphometric and echocardiographic data, and analyzed protein expression of sarcoplasmic reticulum calcium ATPase (SERCA2a), phospholamban (PLB), nuclear factor erythroid type 2 (Nrf2) and hemeoxygenase 1 (HO-1). Also were quantitated concentrations of hydrogen peroxide (H2O2) and total glutathione in homogenized of cardiac tissue. The infarcted animals, treated or not, showed cardiac hypertrophy, independent of the dose of treatment. The AMI has caused a decline in cardiac function parameters, and treatment with T4 was not able to reverse these effects. The protein expression of PLB and Nrf2 decreased after AMI. Animals treated with T4 in their higher doses had values of Nrf2 protein expression similar to those animals of the SHAM group. The infarcted groups and treated with T4 at doses of 2.4 and 6.0 mg / L had higher SERCA2a expression when compared to the sham group. The concentrations of H2O2 and total glutathione were not altered after AMI, and treatment with T4 did not alter these parameters. In short, since the treatment dose of 6.0 mg / L modulates the expression of Nrf2, an important protein for the redox state of the cell, we suggest what might be going on an adaptation of antioxidant systems distinct from those analyzed in this study and are also regulated by this transcription factor.
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Efeitos do tratamento com tiroxina no remodelamento cardíaco pós-infarto agudo do miocárdio e em parâmetros de estresse oxidativoBerger, Bruno da Rocha January 2012 (has links)
O infarto agudo do miocárdio (IAM) é um evento que acomete milhares de pessoas ao redor do mundo. Após o IAM são desencadeados diversos processos, como alterações na expressão de proteínas envolvidas na contratilidade cardíaca e no remodelamento cardíaco após o IAM, bem como o desequilíbrio no estado redox da célula, que podem levar a um grave prognóstico. A utilização dos hormônios da tireoide vem sendo amplamente estudada na tentativa de desenvolver um método terapêutico eficiente para o tratamento do IAM. Desta forma, o objetivo deste estudo foi verificar os efeitos da tiroxina (T4) sobre a expressão e a concentração de antioxidantes e pró-oxidantes e sobre a expressão de proteínas relacionadas ao metabolismo do cálcio, e suas possíveis relações com a melhora na função cardíaca após o IAM. Foram utilizados ratos Wistar, divididos nos seguintes grupos experimentais: SHAM, infartado (IAM) e infartado e tratado com T4 nas doses de 1,2, 2,4 e 6,0 mg/L de água de beber. O tratamento foi iniciado 24 horas após a indução do IAM e após 14 dias foram coletados dados morfométricos e ecocardiográficos, além de analisadas as expressões das proteínas cálcio ATPase do retículo sarcoplasmático (SERCA2a), fosfolambam (PLB), fator nuclear eritroide do tipo 2 (Nrf2) e hemeoxigenase 1 (HO-1). Também foram quantificadas as concentrações de peróxido de hidrogênio (H2O2) e de glutationa total em homogeneizado de tecido cardíaco. Os animais infartados, tratados ou não, apresentaram hipertrofia cardíaca independente da dose do tratamento. O IAM provocou uma redução da função cardíaca, e o tratamento com T4 não foi capaz de reverter esses efeitos. A expressão das proteínas PLB e Nrf2 diminuiu após o IAM. Os animais tratados com T4 em suas doses mais altas apresentaram valores da expressão da proteína Nrf2 semelhantes aos animais do grupo SHAM. Os grupos infartado e tratado com T4 nas doses de 2,4 e 6,0 mg/L apresentaram valores de expressão da SERCA2a maiores quando comparados com o grupo SHAM. As concentrações de H2O2 e de glutationa total não foram alteradas após o IAM, e o tratamento com T4 também não alterou estes parâmetros. Em suma, uma vez que a dose de T4 de 6,0 mg/L modulou a expressão do Nrf2, uma proteína importante para o estado redox da célula, sugerimos que poderia estar ocorrendo uma adaptação de sistemas antioxidantes distintos dos analisados neste estudo e que também são regulados por este fator de transcrição. / The acute myocardial infarction (AMI) is an event that affects thousands of people around the world. After AMI are triggered several processes, such as changes in expression of proteins involved in cardiac contractility and cardiac remodeling, as well as the cell redox state imbalance, which can lead to serious prognosis. The use of thyroid hormones has been widely studied in an attempt to develop an efficient therapeutic method for treatment of AMI. Thus, the objective of this study was to investigate the effects of thyroxine (T4) on expression and concentration of antioxidant and pro-oxidants and the expression of proteins related to calcium metabolism, and their possible relationships with improvement in cardiac function after AMI. Wistar rats were divided into the following groups: SHAM, myocardial infarction (AMI) and myocardial infarction and treated with T4 at doses of 1,2, 2,4 and 6,0 mg / L of drinking water. Treatment was initiated 24 hours after induction of AMI and after 14 days were collected morphometric and echocardiographic data, and analyzed protein expression of sarcoplasmic reticulum calcium ATPase (SERCA2a), phospholamban (PLB), nuclear factor erythroid type 2 (Nrf2) and hemeoxygenase 1 (HO-1). Also were quantitated concentrations of hydrogen peroxide (H2O2) and total glutathione in homogenized of cardiac tissue. The infarcted animals, treated or not, showed cardiac hypertrophy, independent of the dose of treatment. The AMI has caused a decline in cardiac function parameters, and treatment with T4 was not able to reverse these effects. The protein expression of PLB and Nrf2 decreased after AMI. Animals treated with T4 in their higher doses had values of Nrf2 protein expression similar to those animals of the SHAM group. The infarcted groups and treated with T4 at doses of 2.4 and 6.0 mg / L had higher SERCA2a expression when compared to the sham group. The concentrations of H2O2 and total glutathione were not altered after AMI, and treatment with T4 did not alter these parameters. In short, since the treatment dose of 6.0 mg / L modulates the expression of Nrf2, an important protein for the redox state of the cell, we suggest what might be going on an adaptation of antioxidant systems distinct from those analyzed in this study and are also regulated by this transcription factor.
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Infarto agudo do miocárdio: uma amostra de atendimento na cidade de Goiânia e o valor prognóstico da ck-mb / Acute myocardial infarction : an assintance sample in Goiânia and the prognostic value of ck- mbCarvalho, Gustavo 26 October 2015 (has links)
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Previous issue date: 2015-10-26 / Background: the specialized early treatment of acute myocardial infarction provides the best prognosis and enzyme values, during in-hospital phase, can correlate with cardiovascular events along the follow-up. The creatino-phosphokinase-MB is still widely used for diagnosis of acute myocardial infarction with ST-elevation. The percutaneous coronary intervention is the main therapeutic method, where the manual aspirative thrombectomy is a possibility of adjuvant treatment. Objectives: to evaluate the systematic chain of care in the myocardial infarction and the levels of CK-MB in cases treated with angioplasty and coronary thrombus aspiration, and assess 6 months follow-up survival. Assess also the association of CK-MB with the Blush grade, ST resolution and the concomitant correlation with delta-T and death. Methods: 835 patients with ST elevation myocardial infarction were analised, from March 2012 to June 2014 in two reference centers in Goiânia-GO. Only those who arrived within 12h underwent invasive treatment, where serial CK-MB and electrocardiogram were obtained and analyzed during the hospitalization. During the six months follow-up there were observed the events death and reinfarction in this group. For associative and correlation analysis there were used Mann-Whitney, Kruskall-Wallis and Spearman tests. For analysis of categorical variables, the Chi-square test or Fisher, and considered significant p<0.05. Results: out of 835 patients, only 51 (6%) presented within the delta T less than 12h, who were invasively treated immediately on admission. 507 (61%) were presented with more than 12h. The curve of the CK-MB showed peak around 12h. Of those treated with invasive aproach on admission, 6 deaths were observed (11.7%) and 1 re-infarction (2%), all of which occurred in the first month of follow-up. Lower Blush grade and resolution of less than 50% in ST-elevation were associated to significantly higher values of CK-MB. Higher values of CK-MB were significantly correlated with higher delta T and higher mortality. Conclusion: contrary to what recommend the guidelines, only few cases who reached the specialised centres had delta T less than 12h, impacting negatively on prognosis. The curve of CK-MB in patients with myocardial infarction invasivelly treated on admission had early peak. The highest levels were observed in the cases with low Blush grade, less than 50% resolution in ST-elevation and larger delta-T, which were related to the worst prognosis. / o tratamento especializado e precoce no infarto agudo do miocárdio proporciona o melhor prognóstico e os valores enzimáticos, na fase intra-hospitalar, podem se correlacionar com eventos cardiovasculares durante o seguimento clínico. A creatino-fosfoquinase-MB ainda é muito utilizada para diagnóstico do infarto agudo do miocárdio com supra-de-ST. A intervenção coronária percutânea é o principal método terapêutico, onde a trombéctomia por aspiração manual é uma possibilidade de tratamento adjuvante. Objetivos: avaliar a sistemática na cadeia de atendimento do infarto do miocárdio, os níveis da CK-MB dos casos tratados com angioplastia e aspiração de trombo coronário e a sobrevida no seguimento de 6 meses. Avaliar também a associação da CK-MB com o Blush, resolução de ST e a correlação concomitante com o delta-T e morte. Métodos: foram analisados 835 pacientes com infarto do miocárdio com supra de ST atendidos de março de 2012 a junho de 2014 em dois centros de referência em Goiânia-GO. Apenas os que chegaram com delta de até 12h foram submetidos ao tratamento invasivo, onde CK-MB e ECG seriados foram obtidos e analisados durante a internação. No seguimento de seis meses foram observados os desfechos morte e reinfarto neste grupo. Para análises associativas e de correlação foram utilizados teste de Mann-Whitney, Kruskall-Wallis e Spearman. Para análise das variáveis categóricas, realizou-se o teste do qui-quadrado ou de Fisher, e considerados significativos p<0,05. Resultados: dos 835 pacientes, somente 51 (6%) apresentaram delta T menor que 12h e foram tratados invasivamente logo na admissão, sendo que 507 (61%) tinham delta T maior que 24h. A Curva da CK-MB mostrou pico próximo de 12h. Daqueles tratados invasivamente na admissão, foram observados 6 óbitos (11,7%) e 1 reinfarto (2%), sendo que todos ocorreram no primeiro mês de seguimento. Blush baixo e resolução de ST menor que 50% no ECG associaram-se significativamente aos valores mais elevados de CK-MB. Valores elevados de CK-MB estiveram significativamente correlacionados com maior delta T e maior mortalidade. Conclusão: contrariamente ao que recomenda as diretrizes, poucos foram os pacientes que chegaram aos centros especializados com delta T menor que 12h, impactando negativamente no prognóstico. A curva de CK-MB em pacientes com infarto tratados invasivamente na admissão teve pico precoce. Os níveis mais elevados foram constatados nos casos com baixo Blush, resolução de ST menor que 50% no ECG e maior delta-T, estando relacionados aos piores prognósticos.
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