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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.
21

Treatment of mitral valve regurgitation in the elderly: a decision cost-effectiveness analysis model

Proctor, Charles N., IV January 2013 (has links)
INTRODUCTION: The ever-changing landscape of the US health care system is characterized by innovation and high-level care, yet it remains in a state of crisis. With the system seemingly locked in this dire state of rising costs, it becomes increasingly important to take costs into account when deciding between multiple treatments for a particular disease by undertaking cost-effectiveness analysis (CEA) studies. In the present study, a model for mitral regurgitation (MR)—a cardiac valvular disease for which multiple treatment options exist with varying degrees of effectiveness, making it a suitable candidate for CEA —was developed to determine the cost-effectiveness of the four main treatments of medical therapy (MT), mitral valve repair (MVR), mitral valve replacement with a mechanical valve (MVPm) and mitral valve replacement with a bioprosthetic valve (MVPb). The goal of the present undertaking was to determine the most cost-effective treatment option for a reference patient given patient-specific inputs to test the functionality of the developed model. METHODS: Input values for costs, probabilities of event’s occurrences and quality-adjusted life-year (QALY) estimates for each treatment option were first obtained from databases and relevant literature. These values were then standardized to account for source variability and input into a decision tree (DT) model created specifically for the present analysis that included branches for each of the four potential interventions, from each of which were three potential outcome arms representing the potential endpoints of each treatment: death, alive with complications and alive without complications. The costs, probabilities and QALY –values of each of the four complications of interest in the study—atrial fibrillation (AFib), stroke, congestive heart failure (CHF) and reoperation—were combined and averaged to create a unified endpoint for the alive with complications branches of the DT. Following the development of the model, the relevant cost, probability and utility values were used to run a simulation to test the functionality of the model using values associated with a fictional 65-year-old Medicare-covered patient with chronic MR to act as a representative of a sizable real-life population. The model results were then used to calculate the incremental cost-effectiveness ratio (ICER)—the standard comparison used in CEA—between treatment options to determine the most cost-effective among them. Following this simulation, one-way sensitivity analyses (SA) were conducted to determine the susceptibility of the result to variations in select input values. RESULTS: The probability-weighted costs of MT, MVR, MVPm and MVPb were found to be $40,387, $60,249, $76,293 and $74,320, respectively, with respective probability-weighted QALYs of 4.298, 4.740, 4.428 and 5.119. The calculation of ICERs from these values led to the conclusion that MVPb dominated all other treatments and had an ICER of $41,370/QALY gained over MT, which was treated as the baseline treatment option. The societal willingness-to-pay (WTP) threshold used in the present study ($62,000/QALY gained) was greater than the ICER, indicating that MVPb is a cost-effective solution to society. The results of the SA indicated that variations in mortality rate within the ranges in the relevant literature have significant effect on the cost-effectiveness of the interventions, with roughly a 4.74% increase in mortality for MVPb or a 5.09% decrease in the rate of MT leading MVPb to be considered cost-ineffective. CONCLUSIONS: The simulation study concluded that for the 65-year-old reference case, MVPb was the most cost-effective option and the additional cost to society was deemed less than society’s WTP for the additional health benefit. The successful simulation of the model indicates it may hold real-world potential and be applicable to numerous other situations with varying input values. Further research into more accurate input values for a larger number of variables need to be determined in order to increase the accuracy and maximize the applicability of the present model. In addition, the model will require further complication via the inclusion of an increasing number of variables to allow for a more accurate determination of cost-effectiveness in a wider range of health scenarios. Thus, the current model described here and a further evolved future model hold great potential for use all across health care in order to help contain rising costs plaguing the current health care system in the United States.
22

Evaluation of the simultaneous indicator-dilution method for detecting mitral regurgitation in dogs /

Hamlin, Robert L. January 1962 (has links)
No description available.
23

HEALTH TECHNOLOGY ASSESSMENT FOR MITRACLIP SYSTEM IN PATIENTS WITH MITRAL REGURGITATION

Lian, Zhengrong 07 1900 (has links)
Approximately 2% of the population have mitral regurgitation (MR) and many may be not tolerant for mitral valve surgery. The objective of this thesis was to investigate the comparative safety, effectiveness, and cost-effectiveness of percutaneous mitral valve repair using MitraClip System for patients with severe MR. Articles in MEDLINE, Embase, CNKI, and the Cochrane Library published from 1997 to February 2017 were searched for evidence of safety and effectiveness. A systematic review was conducted to address the uncertainty in the safety and effectiveness of MitraClip system in patients with MR. A cost-effectiveness analysis and cost-utility analysis in U.S. settings was conducted to address the uncertainty in health economic evaluation for the MitraClip system. One randomized trial and seven observational studies were included in the systematic review. The pooled data show that 30-day, one-year and two-year survival are similar in MitraClip arm and surgery arm. Residual MR occurs more frequently after MitraClip therapy than surgery, especially in younger patients, functional MR patients, and patients whose LVEF<50%. The risk of 30-day major adverse event from lower odds ratio appeared to be lower in older patients and patients whose LVEF≥50%.For economic evaluation, the base case incremental costs per LY and per QALY were $ 28,217.18 and $27,344.38 US dollars, respectively. Results were most sensitive to alternative assumptions regarding time horizon and long-term survival. Therefore, low quality of evidence due to lack of conclusive RCT data suggested that MitraClip system may provide improvements in MR, patients’ quality of life and survival advantage. It is cost-effective as threshold of $50,000 U.S. dollars per QALY gained for high surgical risk patients. Future RCT designed to reduce confounding and lessen participant attrition, which have adequate sample size, consistent reporting of outcomes, and adequate length of follow-up period will better evaluate the clinical benefits of the MitraClip System. / Thesis / Master of Health Sciences (MSc) / Mitral regurgitation is an abnormal leakage of blood back into the left heart chambers. About 2% of the population who have chronic mitral regurgitation are elderly and are at high risk for surgery. For such patients, a treatment has been proposed that involves a catheter puncturing the skin of the groin and travelling all the way to the affected valve to deploy a device that clips and repairs the valve leaflets (a mitral valve clip). This thesis sought to compare the safety, effectiveness and cost-effectiveness of mitral valve clips with current standards of care in patients at high risk for surgery. To address this question, we searched, critically appraised, and collated existing research evidence. We found that this new treatment was not harmful and may provide a survival advantage. In addition, the approach may be cost-effective when compared to current stand of care in patients at high risk for surgery.
24

The longitudinal outcome of canine myxomatous mitral valve disease in dogs: The LOOK Mitral study

Franchini, Alessandra 07 June 2022 (has links)
Myxomatous mitral valve disease (MMVD) is the most common heart disease in dogs. However, prospectively acquired data describing the natural history and prognostic factors in a large population of dogs affected by this disease are sparse. Thus, the Longitudinal Outcome of canine (K9) myxomatous mitral valve disease registry (LOOKmitral) was established to prospectively collect clinical and diagnostic data from a large population of dogs affected by MMVD. A total of 6,102 dogs were enrolled in the LOOK-mitral registry from November 1st, 2015, to October 31st, 2018, in thirteen cardiology specialty practices. We first described the baseline characteristics of the dogs enrolled in the registry, which mainly confirmed previous findings. Moreover, we provided new additional results, such as the presence of systolic dysfunction in some small breed dogs and how the intensity of the murmur correlates with the severity of MMVD also in large breed dogs. Second, we described the baseline treatment characteristics at the time of enrollment. These data showed that the results of the "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly" (EPIC) trial and left atrial and left ventricular dimensions, assessed by echocardiography, influenced veterinary cardiologist's prescription of cardiovascular drugs in affected dogs. Lastly, we evaluated predictors of reoccurrence of congestive signs within 180 days after successfully treating the first episodes of heart failure in dogs enrolled in the LOOKMitral registry. While this study failed to identify accurate predictors of recurrence, dogs with larger left ventricular internal dimensions at end-diastole were more likely to present with reoccurrence of clinical signs suggesting that closer monitoring of these dogs may be recommended. / Doctor of Philosophy / Despite being the most common heart disease in dogs, data on a large group of dogs affected by myxomatous mitral valve disease (MMVD) are currently sparse in veterinary medicine. The Longitudinal Outcome Of canine (K9) Mitral valve disease (LOOK-Mitral) was established in 2015 to collect data on a large population of dogs affected by MMVD. A total of 6,102 dogs were enrolled in thirteen referral centers over three years. First, the baseline characteristics of dogs enrolled in the registry were described. These data mainly confirmed previous findings. Moreover, they provided some new insight like the possible presence of contractile dysfunction in some small breed dogs and the correlation between the intensity of the heart murmur and the severity of the disease also in large breed dogs. Second, we described the medical treatment prescribed or modified by veterinary cardiologists at the enrollment visit. These data showed that the "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly" (EPIC) trial, a clinical trial published during the enrollment period, and the heart ultrasound (echocardiography) data influence cardiologist prescription habits. Lastly, we evaluated if any clinical or echocardiographic variable could predict the reoccurrence of clinical signs of heart failure within 180 days from the first manifestation of those clinical signs in dogs enrolled in the LOOK-Mitral registry. While this study failed to accurately identify predictors of reoccurrence, dogs with larger left ventricular chamber sizes were more likely to present reoccurrence of clinical signs suggesting that closer monitoring of these dogs may be recommended.
25

Análise ecocardiográfica anatômica e funcional intraoperatória da valva mitral em pacientes com prolapso valvar submetidos à valvoplastia cirúrgica: estudo transesofágico bidimensional e tridimensional / Intraoperative anatomic and functional analyses of mitral valve in patients with valve prolapsed submitted to surgical valvuloplasty: a two-dimensional and three-dimensional transesophageal study

Pardi, Mirian Magalhães 01 December 2014 (has links)
Introdução: Embora o papel da ecocardiografia transesofágica (ETE) esteja bem estabelecido na avaliação morfológica e funcional da valva mitral e na seleção dos pacientes com prolapso da valva mitral (PVM) para a cirurgia reparadora, o impacto da ETE tridimensional (3D) no resultado cirúrgico ainda não está bem demonstrado. Os objetivos deste trabalho foram avaliar o valor diagnóstico adicional da ETE 3D em comparação com a técnica bidimensional (2D) e a associação de parâmetros anatômicos tridimensionais com o resultado cirúrgico em pacientes com PVM submetidos à valvoplastia. Métodos: Para a análise comparativa da sensibilidade, especificidade e acurácia diagnóstica entre ETE 2D e 3D, foram incluídos 62 pacientes operados por PVM com insuficiência importante, sendo a inspeção cirúrgica considerada padrão-ouro. Para a análise 3D, foram estudados 54 pacientes submetidos à plástica valvar que foram divididos em 2 grupos de acordo com o grau da insuficiência mitral pós-operatória (grupo 1, insuficiência mitral ausente ou grau I; grupo 2, insuficiência mitral grau II ou III). Foram medidos pela quantificação 3D os seguintes parâmetros anatômicos: diâmetros anteroposterior e intercomissural, altura, circunferência e área do anel mitral; comprimento, área e linha de coaptação das cúspides; volume e altura do prolapso; distância dos músculos papilares à borda da cúspide; e ângulos mitroaórtico e não planar. Para a identificação de variáveis associadas aos grupos de resultados cirúrgicos, foi realizada análise univariada (teste t de Student para as variáveis contínuas e teste qui-quadrado ou o teste de Fisher para as variáveis categóricas), análise multivariada com método de regressão logística e curva ROC para a obtenção do ponto de corte. Resultados: A ETE 2D apresentou maior sensibilidade no diagnóstico de prolapso nos segmentos A2, P1 e P3 que a ETE 3D (p = 0,019, 0,023, 0,012, respectivamente) enquanto que a ETE 3D apresentou maior especificidade no segmento P1 (p = 0,006). Não houve diferença na acurácia diagnóstica ente os dois métodos. A presença de prolapso das duas cúspides (p = 0,041) e a distância do músculo papilar posteromedial à borda da cúspide (p = 0,038) foram maiores no grupo 2. Análise multivariada identificou prolapso das duas cúspides e distância do músculo papilar posteromedial à borda da cúspide maior que 30 mm como fatores associados à insuficiência mitral pós-operatória grau II ou III (p = 0,039 e 0,015, respectivamente), e com risco de 5,3 e 6,3 vezes maior de insuficiência significativa pós-operatória, respectivamente. Conclusões: A ETE 2D e 3D apresentaram acurácia equivalente no diagnóstico de PVM, com maior sensibilidade da ETE 2D no diagnóstico de prolapso nos segmentos A2, P1 e P3, e maior especificidade da ETE 3D no segmento P1. A distância do músculo papilar posteromedial à borda da cúspide obtida pela análise quantitativa 3D e a presença de prolapso das duas cúspides mostraram associação com o grau da insuficiência mitral pós-operatória grau II e III / Background: Although the transesophageal echocardiography (TEE) is well established in the morphological and functional assessment of the mitral valve and in the choice of patients with mitral valve prolapse (MVP) eligible to valvuloplasty, the impact of tridimensional (3D) TEE on surgical results has not been well demonstrated yet. The present study aimed to evaluate the additional diagnostic value of 3D TEE in comparison with bidimensional (2D) technique, as well as the correlation between 3D anatomical parameters and the surgical results in patients with MVP submitted to valvuloplasty. Methods: In order to compare the sensitivity, specificity, and accuracy between 2D and 3D TEE, 62 patients with MVP and severe mitral regurgitation were enrolled; surgical appraisal was considered as the gold-standard. Regarding 3D analysis, 54 patients submitted to valvuloplasty were divided in two groups, according to their postoperative mitral regurgitation grades (group 1, absent or grade I mitral regurgitation; and group 2, grade II or III mitral regurgitation). The following parameters were assessed quantitatively by 3D TEE: anteroposterior diameter, commissural width, height, circumference and area of the mitral ring; anterior and posterior leaflets length, leaflets surface area, coaptation length, volume and height billow; distance from the tip of the anterolateral and posteromedial papillary muscle to leaflet border; non-planar and aortic-mitral angles. Univariate analysis (Student t test for continuous variables and Chi-square or Fischer test to the categorical ones), multivariate and ROC curve analyses were performed to identify the relationship between anatomical parameters and surgical results (p < 5%). Results: 2D TEE showed higher sensitivity to diagnose MVP in A2, P1, and P3 segments, when compared with 3D TEE (p= 0.019, 0.023, and 0.012, respectively), while 3D TEE showed greater specificity to identify P1 segment (p= 0.006). No difference was observed in the accuracy between both methods. The presence of bileaflet prolapse (p= 0.041) and the distance from posteromedial papillary muscle to leaflet border (p= 0.038) were higher in group 2. Multivariate analysis showed that bileaflet prolapse and distance of more than 30 mm from posteromedial papillary muscle to leaflet border were related to grade II or III postoperative mitral regurgitation (p= 0.039 and 0.015, respectively), representing 5.3 and 6.3 more risk of significant mitral regurgitation, respectively. Conclusions: Both 2D TEE and 3D TEE presented similar accuracy in the diagnosis of MVP; 2D TEE showed higher sensitivity to diagnose the prolapse in A2, P1 and P3 segments, while the 3D TEE presented greater specificity to identify the affected P1 segment. The distance from the tip of the posteromedial papillary muscle to the leaflet border quantitatively estimated by 3D TEE and the evidence of bileaflet prolapse showed to be associated to the degree of mitral regurgitation after valvuloplasty
26

Análise ecocardiográfica anatômica e funcional intraoperatória da valva mitral em pacientes com prolapso valvar submetidos à valvoplastia cirúrgica: estudo transesofágico bidimensional e tridimensional / Intraoperative anatomic and functional analyses of mitral valve in patients with valve prolapsed submitted to surgical valvuloplasty: a two-dimensional and three-dimensional transesophageal study

Mirian Magalhães Pardi 01 December 2014 (has links)
Introdução: Embora o papel da ecocardiografia transesofágica (ETE) esteja bem estabelecido na avaliação morfológica e funcional da valva mitral e na seleção dos pacientes com prolapso da valva mitral (PVM) para a cirurgia reparadora, o impacto da ETE tridimensional (3D) no resultado cirúrgico ainda não está bem demonstrado. Os objetivos deste trabalho foram avaliar o valor diagnóstico adicional da ETE 3D em comparação com a técnica bidimensional (2D) e a associação de parâmetros anatômicos tridimensionais com o resultado cirúrgico em pacientes com PVM submetidos à valvoplastia. Métodos: Para a análise comparativa da sensibilidade, especificidade e acurácia diagnóstica entre ETE 2D e 3D, foram incluídos 62 pacientes operados por PVM com insuficiência importante, sendo a inspeção cirúrgica considerada padrão-ouro. Para a análise 3D, foram estudados 54 pacientes submetidos à plástica valvar que foram divididos em 2 grupos de acordo com o grau da insuficiência mitral pós-operatória (grupo 1, insuficiência mitral ausente ou grau I; grupo 2, insuficiência mitral grau II ou III). Foram medidos pela quantificação 3D os seguintes parâmetros anatômicos: diâmetros anteroposterior e intercomissural, altura, circunferência e área do anel mitral; comprimento, área e linha de coaptação das cúspides; volume e altura do prolapso; distância dos músculos papilares à borda da cúspide; e ângulos mitroaórtico e não planar. Para a identificação de variáveis associadas aos grupos de resultados cirúrgicos, foi realizada análise univariada (teste t de Student para as variáveis contínuas e teste qui-quadrado ou o teste de Fisher para as variáveis categóricas), análise multivariada com método de regressão logística e curva ROC para a obtenção do ponto de corte. Resultados: A ETE 2D apresentou maior sensibilidade no diagnóstico de prolapso nos segmentos A2, P1 e P3 que a ETE 3D (p = 0,019, 0,023, 0,012, respectivamente) enquanto que a ETE 3D apresentou maior especificidade no segmento P1 (p = 0,006). Não houve diferença na acurácia diagnóstica ente os dois métodos. A presença de prolapso das duas cúspides (p = 0,041) e a distância do músculo papilar posteromedial à borda da cúspide (p = 0,038) foram maiores no grupo 2. Análise multivariada identificou prolapso das duas cúspides e distância do músculo papilar posteromedial à borda da cúspide maior que 30 mm como fatores associados à insuficiência mitral pós-operatória grau II ou III (p = 0,039 e 0,015, respectivamente), e com risco de 5,3 e 6,3 vezes maior de insuficiência significativa pós-operatória, respectivamente. Conclusões: A ETE 2D e 3D apresentaram acurácia equivalente no diagnóstico de PVM, com maior sensibilidade da ETE 2D no diagnóstico de prolapso nos segmentos A2, P1 e P3, e maior especificidade da ETE 3D no segmento P1. A distância do músculo papilar posteromedial à borda da cúspide obtida pela análise quantitativa 3D e a presença de prolapso das duas cúspides mostraram associação com o grau da insuficiência mitral pós-operatória grau II e III / Background: Although the transesophageal echocardiography (TEE) is well established in the morphological and functional assessment of the mitral valve and in the choice of patients with mitral valve prolapse (MVP) eligible to valvuloplasty, the impact of tridimensional (3D) TEE on surgical results has not been well demonstrated yet. The present study aimed to evaluate the additional diagnostic value of 3D TEE in comparison with bidimensional (2D) technique, as well as the correlation between 3D anatomical parameters and the surgical results in patients with MVP submitted to valvuloplasty. Methods: In order to compare the sensitivity, specificity, and accuracy between 2D and 3D TEE, 62 patients with MVP and severe mitral regurgitation were enrolled; surgical appraisal was considered as the gold-standard. Regarding 3D analysis, 54 patients submitted to valvuloplasty were divided in two groups, according to their postoperative mitral regurgitation grades (group 1, absent or grade I mitral regurgitation; and group 2, grade II or III mitral regurgitation). The following parameters were assessed quantitatively by 3D TEE: anteroposterior diameter, commissural width, height, circumference and area of the mitral ring; anterior and posterior leaflets length, leaflets surface area, coaptation length, volume and height billow; distance from the tip of the anterolateral and posteromedial papillary muscle to leaflet border; non-planar and aortic-mitral angles. Univariate analysis (Student t test for continuous variables and Chi-square or Fischer test to the categorical ones), multivariate and ROC curve analyses were performed to identify the relationship between anatomical parameters and surgical results (p < 5%). Results: 2D TEE showed higher sensitivity to diagnose MVP in A2, P1, and P3 segments, when compared with 3D TEE (p= 0.019, 0.023, and 0.012, respectively), while 3D TEE showed greater specificity to identify P1 segment (p= 0.006). No difference was observed in the accuracy between both methods. The presence of bileaflet prolapse (p= 0.041) and the distance from posteromedial papillary muscle to leaflet border (p= 0.038) were higher in group 2. Multivariate analysis showed that bileaflet prolapse and distance of more than 30 mm from posteromedial papillary muscle to leaflet border were related to grade II or III postoperative mitral regurgitation (p= 0.039 and 0.015, respectively), representing 5.3 and 6.3 more risk of significant mitral regurgitation, respectively. Conclusions: Both 2D TEE and 3D TEE presented similar accuracy in the diagnosis of MVP; 2D TEE showed higher sensitivity to diagnose the prolapse in A2, P1 and P3 segments, while the 3D TEE presented greater specificity to identify the affected P1 segment. The distance from the tip of the posteromedial papillary muscle to the leaflet border quantitatively estimated by 3D TEE and the evidence of bileaflet prolapse showed to be associated to the degree of mitral regurgitation after valvuloplasty
27

Análise morfofuncional cardíaca com o uso da ecocardiografia tridimensional em tempo real em indivíduos submetidos à plastia valvar mitral pela técnica de duplo teflon / Cardiac morphologic and functional analysis using real time tridimensional echocardiography in individuals submitted to mitral valve repair by double teflon technique

Guedes, Marco Antonio Vieira 17 August 2010 (has links)
INTRODUÇÃO: A plastia valvar mitral é o tratamento de escolha para a correção da insuficiência mitral mixomatosa. Estudos ecocardiográficos tridimensionais demonstram que a plastia mitral com implante de anéis protéticos altera a morfologia e a função do anel valvar mitral, porém a literatura é escassa em relação ao comportamento do anel mitral após a plastia mitral sem utilização de anéis protéticos. OBJETIVO: Analisar a morfologia e a função cardíaca de indivíduos submetidos à plastia valvar mitral pela técnica de Duplo Teflon, através da ecocardiografia tridimensional em tempo real. CASUÍSTICA: Foram incluídos 14 pacientes portadores de insuficiência mitral secundária a degeneração mixomatosa, que foram submetidos à plastia valvar mitral pela técnica de Duplo Teflon. Destes, 10 pacientes eram do sexo masculino e a idade média foi de 61,3 ± 11,2 anos. Em relação à classe funcional, 13 pacientes encontravam-se em classe III ou IV no período pré-operatório. Na análise ecocardiográfica pré-operatória, o valor médio do volume diastólico final do ventrículo esquerdo foi 156,57 ± 46,61ml, e a fração de ejeção do ventrículo esquerdo variou de 38 a 68%, com média de 57,93 ± 6,67%. O valor médio do anel mitral posterior foi 6,97 ± 0,13 cm. MÉTODOS: Os pacientes foram avaliados nos períodos pré-operatório, pós-operatório imediato (POI), 6 meses e 1 ano após a plastia mitral. A ecocardiografia tridimensional avaliou a morfologia do anel mitral através das medidas do anel anterior e posterior, dos diâmetros transversos e da área valvar. A função anular foi avaliada pela relação entre as áreas valvares internas durante a sístole e diástole. Foram avaliados os volumes e a função do átrio e do ventrículo esquerdos. Foi utilizado teste de análise de variância de medidas repetidas para o estudo estatístico, sendo considerado estatisticamente significante p < 0,05. RESULTADOS: O anel mitral posterior demonstrou uma redução significativa (p<0,001) no POI, que manteve-se estável durante o estudo. Não houve variação significativa na área valvar durante o estudo. Houve uma redução significativa nos diâmetros ântero-posterior e médio-lateral no POI (p<0,001), porém houve um aumento significativo no diâmetro médio-lateral entre POI e 1 ano. A fração de variação do anel mitral durante o ciclo cardíaco, ao longo do estudo, variou entre 30,92 e 35,75%, não havendo diferença estatisticamente significante. A análise dos volumes sistólicos, atrial e ventricular, demonstrou uma redução volumétrica significativa entre POI e 1 ano (p=0,028 e p=0,020, respectivamente). Entre o pré-operatório e 1 ano, houve uma redução média de 19,9% e 15,4% nos volumes atrial e ventricular, respectivamente. Os volumes diastólicos atrial e ventricular apresentaram uma redução significativa no POI (p<0,001 e p=0,024, respectivamente), permanecendo estáveis ao longo do estudo. Houve aumento na fração de ejeção do átrio esquerdo após 6 meses (p<0,001), porém não houve variação na função ventricular esquerda. CONCLUSÕES: A plastia mitral com a anuloplastia segmentar pela técnica do Duplo Teflon reduziu o anel posterior da valva mitral, que permaneceu estável no período de um ano. A variação da área anular mitral durante o ciclo cardíaco permaneceu estável durante o estudo. Além disso, houve um remodelamento reverso atrial e ventricular esquerdo, associado à melhora na função do átrio esquerdo / INTRODUCTION: Mitral valve repair is the treatment of choice to correct mixomatous mitral insufficiency. Tridimensional echocardiography studies demonstrate that mitral repair using prosthetic ring implant modifies mitral valve annulus morphology and function, although the literature related to mitral valve annulus behavior after mitral repair without use of prosthetic rings is scarce. OBJECTIVE: Analyze cardiac morphology and function using real time tridimensional echocardiography in individuals submitted to mitral valve repair with Double Teflon technique. CASUISTIC: Were included 14 patients with mitral valve insufficiency secondary to mixomatous degeneration that were submitted to mitral valve repair with the Double Teflon technique. Of them, 10 patients were male and the mean age was 61.3 ± 11.2 years. According to preoperatively functional class, 13 patients were in class III or IV. In preoperative echocardiographic analysis, the mean value of left ventricle end diastolic volume was 156.57 ± 46.61ml, and the left ventricle ejection fraction ranged between 38 and 68%, with average of 57.93 ± 6.67%. The mean value of the posterior annulus was 6.97 ± 0.13 cm. METHODS: Patients were evaluated in preoperative period, immediate postoperative period, 6 months and 1 year after mitral repair. Tridimensional echocardiography evaluated mitral annulus morphology by anterior and posterior measurements, transverse diameters and valve area. The annular function was evaluated through the ratio between internal valve areas during systole and diastole. Were evaluated left atrial and ventricle volumes and function. Statistic analysis was made by repeated measures ANOVA test and was considered statistically significant p < 0.05. RESULTS: Posterior mitral annulus demonstrated a significant reduction in immediate postoperative period (p<0.001), remaining stable during the study. There was no significant variation in valve area during the study. There was a significant reduction in anteroposterior and mediolateral diameters in the immediate postoperative period (p<0.001), although there was a significant increase in mediolateral diameter between immediate postoperative period and 1 year. Annular area variation over the cardiac cycle during the study ranged between 30.92 and 35.75%, without statistic significance. The analysis of systolic volumes, atrial and ventricular, demonstrated a significant volumetric reduction between immediate postoperative period and 1 year (p=0.028 and p=0.020, respectively). Between preoperative period and 1 year, there was a mean reduction in atrial and ventricle volumes of 19.9% and 15.4%, respectively. Atrial and ventricle diastolic volumes presented a significant reduction in immediate postoperative period (p<0.001 and p=0.024, respectively), remaining stable during the study. There was an increase in left atrial ejection fraction after 6 months (p<0.001), although there was no significant variation in left ventricle ejection fraction. CONCLUSIONS: Mitral valve repair with segmentar annuloplasty with the Double Teflon technique reduced the posterior mitral annulus, which remained stable in 1 year period. The variation in mitral annulus area during cardiac cycle remained stable during the study. Furthermore, there was a left atrial and ventricle reverse remodeling, associated with an improvement in left atrial function
28

Investigation into mechanisms of functional mitral regurgitation by advanced echocardiographic technologies--dyssynchrony and beyond. / CUHK electronic theses & dissertations collection

January 2010 (has links)
Cardiac resynchronization therapy (CRT) is an established therapy for patients with advanced congestive heart failure and prolonged QRS duration, aiming at correcting dyssynchrony in the left ventricle (LV). Apart from the beneficial effects on cardiac function and LV reverse remodeling, reduction in functional MR has been observed by Doppler echocardiography after CRT. On the other hand, functional mitral regurgitation (MR) in fact varies over the cardiac cycle that a biphasic pattern has been reported, i.e. early- and late-systolic peaks with a mid-systolic decrease in regurgitant flow. Nevertheless, it remains to be explored whether (1) the improvement of MR leads to a greater extent of LV reverse remodeling; (2) the different components (i.e. early- and late-systolic) of MR improve and their predictors if any. / Despite comparable ejection fraction, higher degree of functional MR was associated with further impairment in short-axis myocardial deformation (circumferential and radial), but not with long-axis myocardial deformation. The degree of LV basal rotation was also lower in the MR patient group. Furthermore, the decrease in myocardial deformation was associated with greater extent of LV remodeling. / In conclusion, LV global mechanical dyssynchrony play a role in determining the severity of functional MR in addition to mitral leaflet tenting in patients with LV systolic dysfunction. Functional MR is associated with further impairment of myocardial deformation, but with differential change in individual component of myocardial deformation. CRT reduces functional MR in both early- and late-systolic phases, by way of improvement in LV remodeling, LV dyssynchrony and mitral leaflet tenting. Meanwhile, the improvement of MR contributes to LV reverse remodeling after CRT. (Abstract shortened by UMI.) / The improvement of functional MR was an independent predictor of LV reverse remodeling after CRT. The extent of LV reverse remodeling (reduction of LV end-systolic volume) was greatest in patients with improvement of MR, followed by those with "mild or no" MR at baseline, and was least in those without improvement of MR. CRT reduced functional MR by reducing both its early- and late-systolic components in heart failure patients. The reductions in LV end-systolic volume and dyssynchrony were related to the improvement of early-systolic MR, while the improvement of late-systolic MR was attributable to the reductions in mitral leaflet tenting and LV dyssynchrony. / The main findings were as follows: LV global systolic dyssynchrony served as an independent predictor for the presence of significant functional MR in patients with LV systolic dysfunction. Although mitral valvular tenting area was the most powerful predictor, LV global systolic dyssynchrony added incremental value to mitral valve tenting area in predicting the presence of significant functional MR. / We performed echocardiography with TDI and 2DSTE in 147 patients of both ischemic and non-ischemic etiologies with LV systolic dysfunction (defined as LV ejection fraction &lt;50%) and 45 normal controls. MR severity, displacement of papillary muscle, mitral annular dilation and dysfunction, mitral leaflet tenting, LV remodeling and function were assessed by 2D and Doppler echocardiography. LV mechanical dyssynchrony indices were derived from TDI velocity. Myocardial strain (i.e. amount of deformation) in longitudinal, circumferential and radial directions and torsion (opposite rotational movement between apex and base of the heart) were measured by 2DTSE. / Liang, Yujia. / "October 2009." / Adviser: Cheuk man Yu. / Source: Dissertation Abstracts International, Volume: 72-01, Section: B, page: . / Thesis (Ph.D)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 169-193). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
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Teste de estresse com Dobutamina em cães com Doença Degenerativa Valvar Mitral /

Rodrigues, Bruno Cristian. January 2018 (has links)
Orientador: Aparecido Antonio Camacho / Coorientador: Evandro Zacché Pereira / Banca: Marlos Gonçalves Sousa / Banca: Rosângela de Oliveira Alves Carvalho / Resumo: A degeneração mixomatosa da válvula mitral (DMVM) é a enfermidade mais comum na clínica de pequenos animais no âmbito das cardiopatias, cuja evolução pode resultar em alterações hemodinâmicas importantes decorrentes dos mecanismos neuro-hormonais compensatórios. Embora seu diagnóstico seja relativamente simples, as alterações intrínsecas podem ser subestimadas pelos exames convencionais, a exemplo da disfunção sistólica e reserva miocárdica que podem passar despercebidas à ecocardiografia. Desta forma, o objetivo do presente estudo foi avaliar a ocorrência de disfunção sistólica em cães com DMVM por meio do teste de estresse farmacológico com dobutamina. Para tanto, foram utilizados três grupos de cães: G1 (n=8) grupo controle, G2 (n=7) animais com DMVM e diâmetro interno do ventrículo esquerdo em diástole indexado à aorta (DIVEd/Ao) < 2,37 e G3 (n=6) animais com DMVM e DIVEd/Ao ≥ 2,37 em um total de 21 animais. O ecocardiograma foi realizado antes (T0) e após (T1) infusão contínua com dobutamina, que foi realizada da seguinte forma: 5μg/kg/minuto por cinco minutos e 10μg/kg/minuto durante 10 minutos (T1). Os resultados foram avaliados pelo teste de Tukey com nível de significância de 5% quanto às variáveis fração de ejeção (FEJ%) (variação percentual média (VPM) de FEJ% antes e após a infusão de dobutamina), VPM de fração de encurtamento (FEC%) e diâmetros internos do ventrículo esquerdo em sístole e diástole indexados pelo diâmetro da aorta (DIVEs/Ao e DIVEd/Ao). Os resulta... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Myxomatous mitral valve disease (MMVD) is the most common cardiopathy in small animals, which evolution may result in important hemodynamic changes due to compensatory neurohormonal mechanisms. Although its diagnosis is relatively simple, intrinsic changes may be underestimated by conventional exams, as systolic dysfunction and myocardial reserve that may go unnoticed by echocardiograph. Therefore, the objective of the present study was to evaluate the occurrence of systolic dysfunction in dogs with MMVD through pharmacological stress test with dobutamine. The dogs were distributed in three groups: G1 (n = 8) control group, G2 (n = 7) animals with MMVD and left ventricular diastolic diameter indexed to the aorta (LVIDd:Ao) < 2.37 and G3 (n = 6) animals with MMVD and LVIDd:Ao ≥ 2.37. The echocardiograph was performed before (T0) and after (T1) continuous infusion of dobutamine, as follows: 5μg/kg/minute for five minutes and 10μg/kg/minute for 10 minutes (T1). The results were evaluated by Tukey test with significance level of 5% for the following variables: ejection fraction (EF%) (mean percentage variation (MPV) of EF% before and after dobutamine infusion), MPV of shortening fraction FS% and internal diameters of left ventricle in systole and in diastole indexed by aortic diameter (LVIDs:Ao and LVIDd:Ao). The results about the MPV FS% and the MPV EF% showed that there was statistical difference between the G1 and G3 groups, as well as between G2 and G3, while the G1 and G3 di... (Complete abstract click electronic access below) / Mestre
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Preditores de desfecho desfavor??vel em crian??as e adolescentes submetidos ?? valvoplastia mitral cir??rgica secund??ria ?? cardiopatia reum??tica cr??nica

Cruz, Renata Cristina Castro 08 June 2018 (has links)
Submitted by JOELMA MAIA (ebmsp-bibliotecacp2@bahiana.edu.br) on 2018-11-09T19:33:56Z No. of bitstreams: 1 RENATA CRISTINA CASTRO CRUZ.pdf: 5406333 bytes, checksum: 70232db974aa49d776c94d3bfe67f800 (MD5) / Approved for entry into archive by JOELMA MAIA (ebmsp-bibliotecacp2@bahiana.edu.br) on 2018-11-09T19:34:51Z (GMT) No. of bitstreams: 1 RENATA CRISTINA CASTRO CRUZ.pdf: 5406333 bytes, checksum: 70232db974aa49d776c94d3bfe67f800 (MD5) / Made available in DSpace on 2018-11-09T19:34:51Z (GMT). No. of bitstreams: 1 RENATA CRISTINA CASTRO CRUZ.pdf: 5406333 bytes, checksum: 70232db974aa49d776c94d3bfe67f800 (MD5) Previous issue date: 2018-06-08 / A cardiopatia reum??tica cr??nica ?? uma doen??a que acomete principalmente crian??as e adolescentes de pa??ses em desenvolvimento, sendo a les??o na valva mitral a mais comum. A plastia da valva mitral ?? superior ?? troca valvar e vem sendo utilizada com bons resultados. Objetivo: Identificar vari??veis preditoras de desfecho desfavor??vel em crian??as e adolescentes submetidas ?? valvoplastia mitral cir??rgica secund??ria ?? cardiopatia reum??tica. M??todos: Estudo retrospectivo em 54 pacientes menores de 16 anos, operados em um hospital pedi??trico terci??rio entre mar??o de 2011 e janeiro de 2017 em Salvador, Bahia, Brasil. As vari??veis preditoras de risco para desfecho desfavor??vel foram: idade, fra????o de eje????o, tipo de les??o valvar, grau de insufici??ncia mitral, dilata????o de c??maras esquerdas, classe funcional no pr??-operat??rio pela New York Heart Association (NYHA), t??cnica cir??rgica utilizada, dura????o da circula????o extracorp??rea (CEC), tempo de an??xia, presen??a de fibrila????o atrial, grau de hipertens??o pulmonar e presen??a de insufici??ncia tric??spide. A compara????o entre as vari??veis foi com os poss??veis desfechos: morte, ICC, choque cardiog??nico, reopera????o, insufici??ncia mitral residual, estenose mitral residual, sepse, acidente vascular cerebral (AVC), sangramento e troca valvar. A presen??a de qualquer desses desfechos de forma isolada ou combinada caracterizou desfecho desfavor??vel como vari??vel dependente ??nica. Resultados: Dos pacientes avaliados, 29 (53,7%) eram do sexo feminino, com m??dia de idade de 10,5 ?? 3,2 anos. 34 (64,2%) eram procedentes do interior da Bahia, 5 (9,4%) eram da regi??o metropolitana e 14 (26,4%) de Salvador. A m??dia de IMC encontrada foi 15,7 ?? 3,5 kg/m2. O tempo de doen??a at?? a realiza????o da cirurgia teve uma mediana de 8 meses (intervalo interquartil 5 ??? 36). A classe funcional de 44 (81,48%) pacientes foi entre NYHA 2 a 4, sendo 13 (25%) NYHA 4. N??o houve morte na amostra estudada. Nenhum paciente apresentou fibrila????o atrial ou precisou ser submetido ?? cirurgia em car??ter de emerg??ncia. Ocorreram eventos durante a cirurgia em 24 (44,4%) dos casos, sendo eles sangramento intenso (2), parada cardiorrespirat??ria (PCR) (6), uso de droga vasoativa (DVA) (8) ou outros (8). O tempo m??dio de circula????o extracorp??rea (CEC) foi 62,7??17,8 min e de an??xia 50 ??15,7 min. O tempo de uso de DVA no p??s-operat??rio imediato teve mediana de 1 dia (intervalo interquartil 1-2 dias). O modelo de regress??o log??stica foi utilizado para avaliar as vari??veis preditoras para o desfecho desfavor??vel. O tempo de uso de DVA foi o ??nico preditor independente para os desfechos estudados (p=0,007). Quanto as vari??veis do ecocardiograma no p??s-operat??rio imediato e tardio, identifica-se associa????o entre insufici??ncia mitral residual e reopera????o (p=0,044), enquanto a insufici??ncia tric??spide (p=0,012) e hipertens??o pulmonar (p=0,012) se associaram ?? presen??a de desfechos desfavor??veis. Conclus??o: O tempo de uso de DVA ?? um preditor independente para desfechos defavor??veis no p??s-operat??rio imediato e tardio, enquanto insufici??ncia mitral residual se associou a reopera????o e tanto a insufici??ncia tric??spide quanto a hipertens??o pulmonar foram associados a desfechos desfavor??veis.

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