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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.
51

A theoretical and experimental analysis of mitral regurgitation and its interactions with pulmonary venous inflow

Grimes, Randall Young 08 1900 (has links)
No description available.
52

Quantification of mitral regurgitation using corrected doppler measurements

Wilkerson, Patrick Wayne 12 1900 (has links)
No description available.
53

Multimodal treatment of women with mitral valve prolapse syndrome

Nevin, Doris Eileen Jacobs January 1997 (has links)
Mitral valve prolapse is the most commonly occurring cardiac condition. It is a benign condition which affects as many as 10% of the population. Some patients have symptomatic mitral valve prolapse. This condition is referred to as mitral valve prolapse syndrome. Symptoms include: chest pain, tachycardia, palpitations, fatigue, dizziness, shortness of breath, headaches, low exercise tolerance, feelings of anxiety, panic attacks, and mood swings. These symptoms adversely effect the patient's quality of life.The purpose of this study was to investigate the response of patients with mitral valve prolapse syndrome to treatment that includes the accepted treatment for panic disorder, and to determine the roles of self-efficacy and of level of spousal support in enhancing the ability of identified patients to cope with mitral valve prolapse syndrome.Thirty-one subjects initially agreed to participate in this study. Of these subjects, fifteen left the study. The leading causes of dropout were lack of spousal support and multiple role stress. The remaining sixteen subjects completed the study. Subjects were randomly divided into three treatment conditions, individual multimodal therapy, couples multimodal therapy, and a waiting list/control group. Treatment consisted of attending a five session psychoeducational program and completing prescribed exercises at home between sessions. The first two sessions examined self-care lifestyle changes that patients could make to alleviate symptoms. The remaining three sessions focused on the over reactiveness of the autonomic nervous system for these patients and the efficacy of learned relaxation procedures. Dependent measures included a Symptom Checklist, Anxiety Sensitivity, Strength and Magnitude of Self-Efficacy and Strength and Magnitude of Interactive Efficacy.Data was analyzed in a two-step process. First, it was analyzed using a multiple single case design format. This was followed by a quantitative analysis of grouped data. In general, the multiple single case design complemented the quantitative analysis. Individual findings in the multiple single case design indicated issues for future research.Participation in treatment was found to aid in decreasing global physical symptoms, decreasing anxiety sensitivity symptoms, and increasing the subject's confidence in her ability to manage her symptoms. The increased level of self-confidence was related significantly to decreasing global physical symptoms. There was a weak, non-statistically significant correlation between increased confidence of self-efficacy and decreased anxiety sensitivity symptoms. Participation in couples multimodal treatment or any treatment was not significantly linked to increased interactive efficacy. Increased interactive efficacy was correlated with increased self-efficacy and decreased global physical symptoms. / Department of Counseling Psychology and Guidance Services
54

The material properties of the chordae tendineae of the mitral valve an in vitro investigation /

Ritchie, Jennifer Lynn. January 2004 (has links) (PDF)
Thesis (M.S.)--Biomedical Engineering, Georgia Institute of Technology, 2005. / Sacks, Michael, Committee Member ; Vito, Raymond, Committee Member ; Guldberg, Robert, Committee Member ; Yoganathan, Ajit, Committee Chair. Includes bibliographical references.
55

The loading and function of the mitral valve under normal, pathological and repair conditions : an in vitro study /

Jimenez-Mejia, Jorge Hernan. January 2006 (has links)
Thesis (Ph. D.)--Biomedical Engineering, Georgia Institute of Technology, 2007. / Ajit Yoganathan, Committee Chair ; Thomas Vassiliades, Committee Member ; Joseph Gorman, Committee Member ; Marc Levenston, Committee Member ; John N. Oshinski, Committee Member.
56

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
57

Avaliação de fatores associados à reoperação em pacientes reumáticos submetidos a cirurgia conservadora da valva mitral / Evaluation of factors associated with reoperation in rheumatic patients undergoing valve repair prior

Severino, Elaine Soraya Barbosa de Oliveira, 1976- 18 August 2018 (has links)
Orientador: Orlando Petrucci Junior / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-18T18:24:11Z (GMT). No. of bitstreams: 1 Severino_ElaineSorayaBarbosadeOliveira_D.pdf: 8406293 bytes, checksum: bc2a25ec83eb02498875fd5f899eb087 (MD5) Previous issue date: 2011 / Resumo: Introdução: A doença cardíaca reumática é a principal causa de doença valvar mitral no Brasil. A superioridade da plastia mitral na regurgitação mitral de etiologia degenerativa já tem sido demonstrada por vários estudos, mas ainda há poucos avaliando os resultados da plastia mitral na doença reumática. Objetivo: O objetivo foi avaliar fatores preditivos de risco para reoperação e mortalidade tardia em população de pacientes reumáticos submetidos à plastia da valva mitral. Material e Método: Este é um estudo retrospectivo. Variáveis clínicas, ecocardiográficas e técnicas cirúrgicas foram anotadas. Foram avaliados apenas pacientes submetidos a reparo da valva mitral exclusivamente, ou em conjunto com plastia da valva tricuspide. Para a análise de reoperação e sobrevida foram utilizadas curvas de Kaplan-Meier. Para a análise univariada das variáveis contínuas foi utilizado o teste t de Student ou Mann-Whitney dependendo do tipo de distribuição da amostra. Para as variáveis discretas foi utilizado o teste do Qui-quadrado. Resultados: Um total de 116 pacientes foram incluídos. O tempo de seguimento médio foi de 58,02 ± 45,33 meses. A idade média dos pacientes foi de 31,19 ± 12,72 anos. No pré-operatório 54,8% dos pacientes estavam em classe funcional I, 24,7% em classe II, 17,2% III e 3,2% em classe funcional IV. Não houve reoperação por sangramento na primeira cirurgia. A taxa de reoperação tardia foi de 12,9% (15 pacientes). A mortalidade cardíaca foi de 5,2% e a geral de 7,8% durante o seguimento tardio. A hipertensão pulmonar no pós-operatório esteve associada ao óbito (P<0,01). Na análise univariada os fatores preditivos de reoperação no pré-operatório foram: medida do átrio esquerdo (P=0,03) e o diâmetro diastólico do ventrículo esquerdo (P=0,01). Durante o seguimento os fatores preditivos de reoperação foram: medida do átrio esquerdo (P<0,01), diâmetro diastólico do ventrículo esquerdo (P<0,01) e a pressão sistólica da artéria pulmonar (P=0,02). Na análise de Kaplan-Meier a variável pré-operatório preditiva de reoperação foi o diâmetro diastólico do ventrículo esquerdo (P=0,01). No seguimento as variáveis preditivas de reoperação foram: a presença de hipertensão pulmonar (P=0,02), presença de insuficiência cardíaca (P<0,01) e a insuficiência mitral (P<0,01). Quanto às técnicas de plastia utilizadas a anuloplastia mitral exclusiva e a anuloplastia tricuspide mostraram maior ocorrência de reoperação (P<0,01 para ambas). A ocorrência de reoperação não esteve associada a menor probabilidade de sobrevida. Conclusão: Os pacientes submetidos a reparo da valva mitral tem fatores preditivos de reoperação no pré e no pós-operatório. Estes pacientes devem ser seguidos de forma mais cautelosa. O reparo da valva mitral e seguro em pacientes reumáticos e com boa sobrevida a longo prazo / Abstract: Introduction: Rheumatic heart valve disease is the most frequent cause of mitral valve disease in Brazil. The advantage of mitral valve repair over mitral valve replacement in degenerative mitral regurgitation has already been demonstrated by several studies, but there are few studies evaluating the early and late outcomes of in rheumatic mitral valve repair . Objective: Our aim was to assess predictive risk factors for mitral reoperation and late mortality in a population of rheumatic patients who underwent mitral valve repair. Methods: This is a retrospective study. Clinical, echocardiographic and surgical techniques were noted. For the analysis of reoperation and survival rates were used Kaplan-Meier curve. For the univariate analysis of continuous variables the Student t test or Mann-Whitney test were used where appropriated. For discrete variables the chisquare test was used. Results: One hundred and sixteen patients were included. The average follow-up was 58.02 ± 45.33 months. The mean age was 31.19 ± 12.72 years. At the preoperative time 54.8% of patients were in functional class I, 24.7% in class II, 17.2% class III, and 3.2% in class IV. There were no reoperations due to bleeding in the early postoperative time. The reoperation rate was 12.9% (15 patients) due to mitral valve degeneration after initial repair within the late follow-up. Cardiac mortality was 5.2% and all causes of death was 7.8% during the same period. The presence of pulmonary hypertension at the late follow-up was associated with death (P<0,01). In the univariate analysis, the risk factors for reoperation in the preoperative time were: left atrium dimension (P = 0.03) and left ventricular end diastolic diameter (P = 0.01). During the late follow-up period, predictive factors for reoperation were: left atrium dimension (P <0.01), left ventricular diastolic diameter (P <0.01) and pulmonary artery systolic pressure (P = 0.02). Kaplan-Meier curve analysis showed the left ventricular diastolic diameter (P = 0.01) associated with reoperation. During the late follow-up, the predictors for reoperation were: the presence of pulmonary hypertension (P = 0.02), congestive heart failure (P <0.01) and mitral regurgitation (P <0.01). Analyzing the techniques used in the initial mitral valve repair annuloplasty exclusively and tricuspid annuloplasty showed a higher incidence of reoperation (P <0.01 in both situations). The reoperation event did not decrease the probability of survival within the follow up period. Conclusion: There are predictors of reoperation in the pre- and postoperative time in patients who underwent rheumatic mitral valve repair. These patients should be followed more cautiously. The rheumatic mitral valve repair is safe and shows good long-term survival / Doutorado / Fisiopatologia Cirúrgica / Doutor em Ciências
58

Patient-Specific Finite Element Modeling of the Mitral Valve

Andison, Christopher January 2015 (has links)
As the most commonly diseased heart valve, the mitral valve (MV) has been the subject of extensive research for many years. Unfortunately, the only treatment options currently available are surgical repair and replacement. Although repair is almost always preferable to replacement, it is often underperformed due to the complexity of MV repair surgeries. Consequently, there is significant interest in generating patient-specific finite element models of the MV for the purpose of simulating mitral repairs. For practical purposes transesophageal echocardiographic (TEE) images are most commonly used to reconstruct the mitral apparatus. However, limitations in ultrasound technology have prevented the detection of leaflet thicknesses. In the current study, a method was developed to accurately model variations in leaflet thicknesses using TEE datasets. Nine healthy datasets were modeled and the leaflet thicknesses were found to closely match previously reported results. As anticipated, normal valve function was also observed over the entire cardiac cycle.
59

Mitral Valve Prolapse, 1st Revision

Holt, Jim 01 January 2013 (has links)
No description available.
60

Mitral Valve Prolapse: Cardiac Arrest With Long-Term Survival

Boudoulas, Harisios, Schaal, Stephen F., Stang, John M., Fontana, Mary E., Kolibash, Albert J., Wooley, Charles F. 01 January 1990 (has links)
Cardiac arrest has been reported in patients with mitral valve prolapse; however, clinical characteristics and survival information are limited since most of the cases reported include autopsy data. Nine patients (2 male, 7 female) with mitral valve prolapse were identified who had cardiac arrest; ventricular fibrillation was documented in 8 patients; resuscitation was unsuccessful in 2. Eight had a history of palpitations (months to 15 years duration) and ventricular arrhythmias, 3 had a history (5-15 years) of recurrent syncope, and 1 was totally asymptomatic. Cardiac catheterization-angiographic studies in 8 patients demonstrated normal coronary artery anatomy and mitral valve prolapse. All 9 patients had auscultatory and echocardiographic evidence of mitral valve prolapse. Seven survivors (6 still alive) were followed from 3 to 14 years after cardiac arrest. A subset of patients with mitral valve prolapse and cardiac arrest is described in whom past medical history is compatible with cardiac arrhythmias or syncope, and whose long-term prognosis appears better than patients with other causes of cardiac arrest.

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