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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.
161

Estudo comparativo do fluxo da artéria torácica interna utilizada \"in situ\" na revascularização miocárdica, com e sem a ligadura dos ramos proximais, utilizando a ecocardiografia Doppler / Comparative study of the internal thoracic artery flow used \"in situ\" for myocardial revascularization, with and without ligation of its proximal branches using Doppler echocardiography

Abreu, José Sebastião de 19 May 2015 (has links)
Fundamento: A artéria torácica interna (ATI) \"in situ\" apresenta predomínio de fluxo sistólico, mas após sua anastomose no sistema coronariano esquerdo torna-se um sistema híbrido com predomínio de fluxo diastólico, sendo a relevância da patência ou não dos grandes ramos proximais da ATI anastomosada controversa quanto à possibilidade de roubo de fluxo. Porém, constata-se que durante o ecocardiograma sob estresse com dobutamina (EED), o estado funcional da ATI anastomosada pode ser avaliado através da reserva coronariana, além da verificação dos distintos efeitos no fluxo sistólico (FS), diastólico (FD) e total (FT = sistólico + diastólico). Objetivo: Verificar por meio da ecocardiografia e Doppler o efeito dos ramos proximais importantes da ATI no fluxo, na reserva de velocidade (RVFC) e de fluxo (RFC) coronariano, em pacientes com fração de ejeção do ventrículo esquerdo (FEVE) preservada (> 50%). Métodos: Em ensaio clínico prospectivo controlado e randomizado, foram avaliados pacientes com (Grupo I) e sem (Grupo II), a ligadura dos ramos proximais importantes da ATI anastomosada na coronária descendente anterior. As avaliações das ATIs em nível supraclavicular e os ecocardiogramas transtorácicos foram realizados no pré-operatório, no pós-operatório precoce, seis meses após a cirurgia em condição basal e durante o EED. Neste, foi alcançada a frequência cardíaca submáxima [(220 - idade) x (0,85)] sem a ocorrência de isquemia no território subjacente à ATI anastomosada em todos os pacientes. Foram medidos o FS, o FD, o FT e o percentual de FD, nos quatro momentos do estudo. O percentual de FD resultou da divisão da integral da velocidade diastólica do fluxo pela integral da velocidade total (sistólica + diastólica) do fluxo. A reserva coronariana foi obtida através do Doppler da ATI anastomosada seis meses após a cirurgia, sendo calculada através da razão entre o valor da variável registrado no EED e em condição basal, utilizando-se para as RVFCs o pico e a média de velocidade diastólica, e para a RFC o FT. As distribuições das variáveis contínuas foram comparadas através do Teste t Student, quando as variáveis eram aproximadamente normais, ou através do Teste da Soma dos Postos de Wilcoxon (Mann-Whitney), quando as variáveis não eram aproximadamente normais. Proporções foram comparadas através do teste exato de Fisher. O valor-p < 0,05 entre os grupos foi considerado estatisticamente significativo. Resultados: O Grupo I (25 pacientes) e o Grupo II (28 pacientes) não foram diferentes quanto às características clínicas e ecocardiográficas, constatando-se a FEVE preservada em todos os casos. O FD não diferiu entre os grupos nos quatro momentos do estudo. Entretanto, verificou-se durante o EED que o FS (19,5 ± 9,3 ml/min vs. 32,7 ± 19,4 ml/min; p < 0,05) e o FT (79,1 ± 21,4 ml/min vs. 101,1 ± 47,4 ml/min; p < 0,05) foram maiores no Grupo II. Contudo, o percentual de FD foi maior no Grupo I (76,4 ± 12,7% vs. 68,9 ± 10%; p < 0,05) durante o EED, em virtude de o Grupo I apresentar menos componente sistólico. O percentual de FD < 50% ocorreu em todos os casos no pré - operatório, em cinco casos no pós - operatório precoce e em dez casos em condição basal seis meses após a cirurgia. Todavia, durante o EED, todos os casos apresentaram o percentual de FD > 50%, sendo este percentual de 100% em cinco casos (quatro no Grupo I). Os grupos não apresentaram diferença entre as RFCs (1,9 ± 0,46 vs. 2,11 ± 0,56; p = 0,143) ou as RVFCs calculadas com o pico (2,17 ± 0,64 vs.2,28 ± 0,63; p = 0,537) e com a média (2,27 ± 0,54 vs.2,50 ± 0,79; p= 0,232) da velocidade diastólica. Conclusão: Concluímos que o adequado estado funcional da ATI anastomosada independe da presença ou ausência dos importantes ramos proximais. Assim, a ligadura dos ramos não determina aumento do fluxo sistólico, diastólico ou total através deste enxerto, e o predomínio diastólico é mais evidente sob a condição estresse. O aumento dos fluxos sistólico e total indicam para a adaptação do fluxo através desta artéria para suprir a ambas, circulação coronariana e não coronariana, nos pacientes que não têm esses ramos ligados durante a cirurgia. Estes achados apontam para o entendimento de que a hipótese do roubo de fluxo pelos ramos não ligados é improvável / Background: The internal thoracic artery (ITA) \"in situ\" has systolic flow predominance, but when grafted to the left coronary artery system, the ITA becomes a hybrid system with diastolic flow predominance. The relevance of the patency or not-patency of the large proximal branches of the ITA graft is controversial in regards to the possibility of flow steal. During dobutamine stress echocardiography (DSE), the functional status of the ITA graft can be assessed by the coronary reserve in addition to assessment of the distinct effects of DSE on systolic (SF), diastolic (DF), and total flow (TF = systolic + diastolic). Objective: To assess, by Doppler echocardiography, the effects of the significant proximal branches of ITA graft in the flow, coronary flow velocity reserve (CFVR) and coronary flow reserve (CFR), in patients with preserved (> 50%) left ventricular ejection fraction (LVEF). Methods: In a prospective randomized controlled clinical trial we evaluate patients with (Group I) and without (Group II) ligation of important proximal branches of the ITA grafted to the anterior descending coronary artery. Supraclavicular assessment of the ITAs and transthoracic echocardiograms were performed, at rest and during DSE, on pre-operative, early and six months post-operative. In all patients, the submaximal heart rate [(220 - age) x (0.85)] was achieved during DSE with no ischemia to the area matching the ITA graft. The SF, DF, TF and percentage of DF were measured in the four moments of this study. The percentage of DF was calculated by the ratio of the integral of the diastolic flow velocity by the integral of the total flow velocity (systolic + diastolic). The coronary reserve was assessed at six months post-operative, and it was calculated by the ratio of the variable during DSE and at rest, using the maximum and the mean of the diastolic flow velocity to calculate the CFVR; and the TF to calculate the CFR. Student\'s t-tests or Wilcoxon\'s rank sum test (Mann-Whitney) were used to examine differences between the groups in normally distributed or not-normally-distributed continuous variables, respectively. Fisher exact test was used to examine the difference in proportions. A p value < 0.05 was considered statistically significant. Results: Group I (25 patients) and Group II (28 patients) were not different regarding to clinical and echocardiographic characteristics, with preservation of the LVEF in all cases. The DF was not different between the groups in the four moments of this study. However, during the DSE, the SF (19.5 ± 9.3 ml/min vs. 32.7 ± 19.4 ml/min, p < 0.05) and TF (79.1 ± 21.4 ml/min vs. 101 1 ± 47.4 ml/min; p < 0.05) were higher in Group II. On the other hand, during the DSE, the percentage of DF was higher in Group I (76.4 ± 12.7% vs. 68.9 ± 10%; p < 0.05), due to its lower systolic component. The percentage of DF < 50% occurred in all cases in the pre-operative, in five cases in the early post-operative and in ten cases, at rest, six months postoperatively. However, during the DSE, all cases showed the percentage of DF > 50%, furthermore five cases (four in Group I) had the percentage of DF of 100%. There was no difference between the groups in regards to CFR (1.9 ± 0.46 vs. 2.11 ± 0.56; p = 0.143), or CFVR calculated using the maximum (2.17 ± 0.64 vs. 2.28 ± 0.63; p = 0.537) and the mean (2.27 ± 0.54 vs. 2.50 ± 0.79; p = 0.232) of the diastolic velocity. Conclusion: The appropriate functional status of the ITA graft does not depend on the ligation or preservation of important proximal ITA branches. Thus, ligation of ITA branches does not determine increase in systolic, diastolic or total flow through the ITA graft, and its diastolic predominance is more evident under stress. The increase in the systolic and total flow indicates an adaptation of the flow through the ITA graft to supply both coronary and non-coronary systems, in those patients that don\'t have the branches ligated during surgery. These findings point towards the hypothesis that the flow steal by unligated branches is unlikely.
162

Assessment of left ventricular remodeling with Doppler echocardiography in patients after acute myocardial infarction compared with cardiovascular magnetic resonance imaging. / CUHK electronic theses & dissertations collection

January 2005 (has links)
Cardiac remodeling after acute myocardial infarction (MI) is an important process that leads to progressive ventricular enlargement and heart failure. Several variables have been identified to predict an increase in left ventricular (LV) volume and a decrease of LV ejection fraction (LVEF) after an acute MI including infarct size, anterior location, cardiac enzyme level, transmurality of the infarct, patency of the infarct-related artery, end systolic volume (ESV) and mitral deceleration time, etc. / Regional disturbances of LV wall motion have long been recognized to occur in patients with cardiac diseases, such as hypertrophic cardiomyopathy, unstable angina, acute ischemia, and MI. Tissue Doppler imaging (TDI) is recently established for detecting regional contractile abnormalities and asynchrony, and can predict reverse remodeling and improved synchronicity after biventricular pacing therapy in heart failure patients. However, it is unclear whether LV asynchrony plays an important role in the evolutionary changes of LV remodeling after an acute infarction and whether it can predict the changes independently. / The identification of transmural extent of myocardial necrosis and degree of non-viability after acute MI is clinically important. TDI-derived strain rate imaging (SRI) quantifies local rate of myocardial deformation and has the potential to differentiate viable from infarcted myocardium. / Therefore, in this study we aimed to investigate: (1) Whether SRI may differentiate transmural from non-transmural MI as assessed by ce-MRI in routine patients post acute infarction, and establish practical cutoff values for identifying transmural scar tissue from non-transmural or subendocardial infarction with viable myocardium. (2) Whether LV systolic and diastolic asynchrony measured by TDI occurs early after acute MI even in the absence of widening of QRS complexes, and determine if this is explained by the site and extent of the infarction measured by ce-MRI. (3) The relationships between serial measurements of infarct size on ce-MRI and LV remodeling process after an acute infarction, and determine whether early assessment of infarct size predicts progressive ventricular enlargement and cardiac dysfunction, and whether it differs with infarct location. (4) The relationships between LV asynchrony, infarct size and LV remodeling, and determine whether early assessment of LV asynchrony by TDI compared with standard clinical correlates of LV remodeling and infarct size predicts progressive ventricular enlargement and cardiac dysfunction. (Abstract shortened by UMI.) / Zhang Yan. / "April 2005." / Adviser: John E. Sanderson. / Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0175. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 161-192). / 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, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.
163

Parâmetros ultrassonográficos bi e tridimensionais em gestações únicas com colo uterino curto / Two and three-dimensional ultrasound parameters in single pregnancies with short cervix

Juliana Valente Codato Marinelli 19 September 2018 (has links)
INTRODUÇÃO: Pouco se sabe sobre parâmetros ultrassonográficos transvaginais possíveis de serem avaliados durante a gestação além do comprimento do colo uterino. A escassa literatura sugere que o volume calculado através da ultrassonografia tridimensional, a quantificação de sinal power Doppler em todo o órgão e o Doppler das artérias uterinas possam sofrer alterações de acordo com o comprimento cervical, e até mesmo anteceder seu encurtamento no processo que leva ao parto. OBJETIVOS: agregar novos parâmetros bi e tridimensionais ultrassonográficos à avaliação do colo uterino em gestações únicas. MÉTODO: Estudo transversal desenvolvido com dados de 2014 a janeiro de 2018 do projeto PROPE, no qual foi realizada ultrassonografia transvaginal em pacientes entre 20 e 23 semanas e 6 dias de gestação. Foram compilados e submetidos à análise secundária os dados de 162 gestantes com comprimento do colo uterino >= 25 mm (grupo Controle), 68 gestantes com comprimento do colo >= 15 mm e < 25 mm (grupo Colo Curto) e 18 gestantes com comprimento do colo < 15 mm (grupo Colo Muito Curto). Foram analisadas as características demográficas e antecedentes obstétricos das gestantes, e foram comparados entre os grupos os parâmetros cervicais de comprimento, volume e vascularização, além do Doppler de artérias uterinas bilateralmente. RESULTADOS: O comprimento médio (± DP) dos colos uterinos de cada grupo foi 35,28 ± 5,12 mm para o grupo Controle, 20,51 ± 2,47 mm para o grupo Colo Curto, e 10,72 ± 2,51 mm para o grupo Colo Muito Curto. Houve diferença entre os grupos quanto à idade materna, cor (etnia) e idade gestacional de inclusão. Quanto aos antecedentes obstétricos, houve associação somente entre a presença de colo curto na gestação atual e pelo menos um parto prematuro anterior em gestantes não nulíparas (p = 0,021). Em relação aos parâmetros ultrassonográficos, verificou-se correlação linear positiva moderada entre volume e comprimento do colo (coeficiente de Pearson=0.587, valor p < 0.0001). Os grupos Controle, Colo Curto e Colo Muito Curto foram estatisticamente diferentes em relação às médias (± DP) de volume (46,38 ± 13,60 cm vs. 32,15 ± 13,14 cm vs. 22,08 ± 11,10 cm, respectivamente)(p <= 0,001), e em relação às médias (± DP) de índice de fluxo (IF) (39,81 ± 6,42 cm vs. 38,73 ± 4,99 cm vs. 36,02 ± 5,34 cm, respectivamente) (p = 0,027), em que a diferença estatística ocorre entre os grupos Controle e Colo Muito Curto. Porém, na presença da informação do volume, após regressão linear, a associação entre os grupos e IF deixa de ser significativa. Também não houve relação entre os grupos estudados e o Doppler de artérias uterinas. CONCLUSÃO: Existe correlação linear positiva entre o volume e o comprimento do colo uterino. Na ausência de informações sobre o volume, comprimento cervical e índices de vascularização não se correlacionam. O comprimento cervical também não está relacionado a alterações no Doppler de artérias uterinas. Apesar das limitações de uma amostra pequena e escassez de dados comparativos na literatura, este estudo foi realizado com uma amostra homogênea da população e abre caminho para maiores pesquisas sobre o assunto / INTRODUCTION: Little is known about transvaginal ultrasound parameters other than cervical length that can be assessed during gestation. The literature suggests that changes in volume on three-dimensional ultrasound, quantification of power Doppler signal in the entire organ, and Doppler sonography of uterine arteries may be related to cervical length, and even precede its shortening during spontaneous delivery. OBJECTIVES: To include new two- and three-dimensional ultrasonographic parameters for evaluation of the uterine cervix in single pregnancies. METHODS: A crosssectional study of data from Project PROPE on transvaginal ultrasonography performed in patients between 20 and 23 weeks and 6 days of gestation from May 2014 to January 2018 was conducted. Secondary analysis of data from 162 pregnant women with uterine cervical length >= 25 mm (Control group), 68 pregnant women with cervical length >= 15 mm and < 25 mm (Short Cervix group), and 18 pregnant women with cervical length < 15 mm (Very Short Cervix group) was performed. The demographic characteristics and obstetric history of the pregnant women were analyzed, and the cervical length, volume, and vascularization were compared between the groups. In addition, Doppler velocimetry of the uterine arteries was performed bilaterally. RESULTS: The mean cervical length (± SD) was 35.28 ± 5.12 mm for the Control group, 20.51 ± 2.47 mm for the Short Cervix group, and 10.72 ± 2, 51 mm for the Very Short Cervix group. The groups differed in maternal age, ethnicity, and gestational age. When analyzing the obstetric history of only non-nulliparous patients we observed a significant association between the presence of a short cervix in the current pregnancy and at least one previous preterm birth (p = 0.021). With regard to the ultrasonographic parameters, we observed a moderate positive linear correlation between the volume and length of the cervix (Pearson coefficient = 0.587, p < 0.0001). The Control, Short Cervix, and Very Short Cervix groups showed differences in the mean (± SD) volume (46.38 ± 13.60 cm vs. 32.15 ± 13.14 cm vs. 22.08 ± 11.10 cm, respectively) (p <= 0.001) and mean (± SD) flow index (FI) parameter of cervical vascularization (39.81 ± 6.42 cm vs. 38.73 ± 4.99 cm vs. 36.02 ± 5.34 cm, respectively) (p = 0.027), and the difference between the Control and Very Short Cervix groups was statistically significant. However, after linear regression, in the presence of volume information, we found no association between the groups and FI. CONCLUSION: Cervical length and volume are positively correlated. When information about the volume is not provided, there\'s no association between cervical length and vascularization. Uterine artery Doppler is not related to cervical length. Despite the limitations of a small sample size and less comparative data in the literature, this study was performed with a homogeneous sample population and paves the way toward further research on the subject
164

Estudo comparativo do fluxo da artéria torácica interna utilizada \"in situ\" na revascularização miocárdica, com e sem a ligadura dos ramos proximais, utilizando a ecocardiografia Doppler / Comparative study of the internal thoracic artery flow used \"in situ\" for myocardial revascularization, with and without ligation of its proximal branches using Doppler echocardiography

José Sebastião de Abreu 19 May 2015 (has links)
Fundamento: A artéria torácica interna (ATI) \"in situ\" apresenta predomínio de fluxo sistólico, mas após sua anastomose no sistema coronariano esquerdo torna-se um sistema híbrido com predomínio de fluxo diastólico, sendo a relevância da patência ou não dos grandes ramos proximais da ATI anastomosada controversa quanto à possibilidade de roubo de fluxo. Porém, constata-se que durante o ecocardiograma sob estresse com dobutamina (EED), o estado funcional da ATI anastomosada pode ser avaliado através da reserva coronariana, além da verificação dos distintos efeitos no fluxo sistólico (FS), diastólico (FD) e total (FT = sistólico + diastólico). Objetivo: Verificar por meio da ecocardiografia e Doppler o efeito dos ramos proximais importantes da ATI no fluxo, na reserva de velocidade (RVFC) e de fluxo (RFC) coronariano, em pacientes com fração de ejeção do ventrículo esquerdo (FEVE) preservada (&gt; 50%). Métodos: Em ensaio clínico prospectivo controlado e randomizado, foram avaliados pacientes com (Grupo I) e sem (Grupo II), a ligadura dos ramos proximais importantes da ATI anastomosada na coronária descendente anterior. As avaliações das ATIs em nível supraclavicular e os ecocardiogramas transtorácicos foram realizados no pré-operatório, no pós-operatório precoce, seis meses após a cirurgia em condição basal e durante o EED. Neste, foi alcançada a frequência cardíaca submáxima [(220 - idade) x (0,85)] sem a ocorrência de isquemia no território subjacente à ATI anastomosada em todos os pacientes. Foram medidos o FS, o FD, o FT e o percentual de FD, nos quatro momentos do estudo. O percentual de FD resultou da divisão da integral da velocidade diastólica do fluxo pela integral da velocidade total (sistólica + diastólica) do fluxo. A reserva coronariana foi obtida através do Doppler da ATI anastomosada seis meses após a cirurgia, sendo calculada através da razão entre o valor da variável registrado no EED e em condição basal, utilizando-se para as RVFCs o pico e a média de velocidade diastólica, e para a RFC o FT. As distribuições das variáveis contínuas foram comparadas através do Teste t Student, quando as variáveis eram aproximadamente normais, ou através do Teste da Soma dos Postos de Wilcoxon (Mann-Whitney), quando as variáveis não eram aproximadamente normais. Proporções foram comparadas através do teste exato de Fisher. O valor-p &lt; 0,05 entre os grupos foi considerado estatisticamente significativo. Resultados: O Grupo I (25 pacientes) e o Grupo II (28 pacientes) não foram diferentes quanto às características clínicas e ecocardiográficas, constatando-se a FEVE preservada em todos os casos. O FD não diferiu entre os grupos nos quatro momentos do estudo. Entretanto, verificou-se durante o EED que o FS (19,5 ± 9,3 ml/min vs. 32,7 ± 19,4 ml/min; p &lt; 0,05) e o FT (79,1 ± 21,4 ml/min vs. 101,1 ± 47,4 ml/min; p &lt; 0,05) foram maiores no Grupo II. Contudo, o percentual de FD foi maior no Grupo I (76,4 ± 12,7% vs. 68,9 ± 10%; p &lt; 0,05) durante o EED, em virtude de o Grupo I apresentar menos componente sistólico. O percentual de FD &lt; 50% ocorreu em todos os casos no pré - operatório, em cinco casos no pós - operatório precoce e em dez casos em condição basal seis meses após a cirurgia. Todavia, durante o EED, todos os casos apresentaram o percentual de FD &gt; 50%, sendo este percentual de 100% em cinco casos (quatro no Grupo I). Os grupos não apresentaram diferença entre as RFCs (1,9 ± 0,46 vs. 2,11 ± 0,56; p = 0,143) ou as RVFCs calculadas com o pico (2,17 ± 0,64 vs.2,28 ± 0,63; p = 0,537) e com a média (2,27 ± 0,54 vs.2,50 ± 0,79; p= 0,232) da velocidade diastólica. Conclusão: Concluímos que o adequado estado funcional da ATI anastomosada independe da presença ou ausência dos importantes ramos proximais. Assim, a ligadura dos ramos não determina aumento do fluxo sistólico, diastólico ou total através deste enxerto, e o predomínio diastólico é mais evidente sob a condição estresse. O aumento dos fluxos sistólico e total indicam para a adaptação do fluxo através desta artéria para suprir a ambas, circulação coronariana e não coronariana, nos pacientes que não têm esses ramos ligados durante a cirurgia. Estes achados apontam para o entendimento de que a hipótese do roubo de fluxo pelos ramos não ligados é improvável / Background: The internal thoracic artery (ITA) \"in situ\" has systolic flow predominance, but when grafted to the left coronary artery system, the ITA becomes a hybrid system with diastolic flow predominance. The relevance of the patency or not-patency of the large proximal branches of the ITA graft is controversial in regards to the possibility of flow steal. During dobutamine stress echocardiography (DSE), the functional status of the ITA graft can be assessed by the coronary reserve in addition to assessment of the distinct effects of DSE on systolic (SF), diastolic (DF), and total flow (TF = systolic + diastolic). Objective: To assess, by Doppler echocardiography, the effects of the significant proximal branches of ITA graft in the flow, coronary flow velocity reserve (CFVR) and coronary flow reserve (CFR), in patients with preserved (&gt; 50%) left ventricular ejection fraction (LVEF). Methods: In a prospective randomized controlled clinical trial we evaluate patients with (Group I) and without (Group II) ligation of important proximal branches of the ITA grafted to the anterior descending coronary artery. Supraclavicular assessment of the ITAs and transthoracic echocardiograms were performed, at rest and during DSE, on pre-operative, early and six months post-operative. In all patients, the submaximal heart rate [(220 - age) x (0.85)] was achieved during DSE with no ischemia to the area matching the ITA graft. The SF, DF, TF and percentage of DF were measured in the four moments of this study. The percentage of DF was calculated by the ratio of the integral of the diastolic flow velocity by the integral of the total flow velocity (systolic + diastolic). The coronary reserve was assessed at six months post-operative, and it was calculated by the ratio of the variable during DSE and at rest, using the maximum and the mean of the diastolic flow velocity to calculate the CFVR; and the TF to calculate the CFR. Student\'s t-tests or Wilcoxon\'s rank sum test (Mann-Whitney) were used to examine differences between the groups in normally distributed or not-normally-distributed continuous variables, respectively. Fisher exact test was used to examine the difference in proportions. A p value &lt; 0.05 was considered statistically significant. Results: Group I (25 patients) and Group II (28 patients) were not different regarding to clinical and echocardiographic characteristics, with preservation of the LVEF in all cases. The DF was not different between the groups in the four moments of this study. However, during the DSE, the SF (19.5 ± 9.3 ml/min vs. 32.7 ± 19.4 ml/min, p &lt; 0.05) and TF (79.1 ± 21.4 ml/min vs. 101 1 ± 47.4 ml/min; p &lt; 0.05) were higher in Group II. On the other hand, during the DSE, the percentage of DF was higher in Group I (76.4 ± 12.7% vs. 68.9 ± 10%; p &lt; 0.05), due to its lower systolic component. The percentage of DF &lt; 50% occurred in all cases in the pre-operative, in five cases in the early post-operative and in ten cases, at rest, six months postoperatively. However, during the DSE, all cases showed the percentage of DF &gt; 50%, furthermore five cases (four in Group I) had the percentage of DF of 100%. There was no difference between the groups in regards to CFR (1.9 ± 0.46 vs. 2.11 ± 0.56; p = 0.143), or CFVR calculated using the maximum (2.17 ± 0.64 vs. 2.28 ± 0.63; p = 0.537) and the mean (2.27 ± 0.54 vs. 2.50 ± 0.79; p = 0.232) of the diastolic velocity. Conclusion: The appropriate functional status of the ITA graft does not depend on the ligation or preservation of important proximal ITA branches. Thus, ligation of ITA branches does not determine increase in systolic, diastolic or total flow through the ITA graft, and its diastolic predominance is more evident under stress. The increase in the systolic and total flow indicates an adaptation of the flow through the ITA graft to supply both coronary and non-coronary systems, in those patients that don\'t have the branches ligated during surgery. These findings point towards the hypothesis that the flow steal by unligated branches is unlikely.
165

Valor da ecocardiografia tridimensional em tempo real em portadores de cardiomiopatia hipertrófica. Comparação com a ecocardiografia bidimensional e a ressonância magnética cardiovascular / Value of real-time three-dimensional echocardiography in patients with hypertrophic cardiomyopathy. Comparison with twodimensional echocardiography and magnetic resonance imaging

Leticia Santos Bicudo 30 November 2007 (has links)
INTRODUÇÃO: A ecocardiografia tridimensional em tempo real (E3DTR) vem provando sua acurácia para quantificar os volumes do ventrículo esquerdo (VE), fração de ejeção (FEVE) e massa em pacientes com cardiomiopatia. Na cardiomiopatia hipertrófica (CMH), onde a morfologia ventricular pode estar muito alterada, a análise das estruturas cardíacas é fundamental para indicação da terapêutica ideal. A ressonância magnética cardiovascular (RMC) é um método superior na análise segmentar do VE em comparação a ecocardiografia bidimensional (E2D), mas com alta complexidade e existente em poucos centros diagnósticos, com contraindicações e limitações para a sua realização. MÉTODOS: Estudo transversal, comparativo, duplo cego, em 20 portadores de CMH, com E2D, E3DTR e RMC realizados com intervalo máximo de 06 meses e armazenados em formato digital. A espessura das paredes, volumes, função sistólica e massa ventricular esquerda foram analisados pelos métodos ecocardiográficos e pela RMC, assim como o movimento anterior sistólico da valva mitral, o índice geométrico do VE e o índice sistólico de dissincronia do VE. ANÁLISE ESTATÍSTICA: Análise estatística pelo coeficiente de concordância de Lin, correlação linear de Pearson e modelo de Bland-Altman. RESULTADOS: Foi obtida exeqüibilidade elevada acima de 94%, dependente do parâmetro avaliado. Concordância satisfatória e forte correlação linear evidenciada para a análise segmentar (Rc>0.84 e r>0.85; p<0.0001) observada para os métodos ecocardiográficos comparados à RMC, com concordância excelente entre os métodos ecocardiográficos (Rc=0,92 e r=0,92, p<0,0001). Concordância satisfatória e forte correlação linear para a fração de ejeção do VE (Rc=0.83 e r=0.93; p<0.0001) pela E3DTR comparada à RMC. Concordância excelente e forte correlação linear para o VDFVE e VSFVE pela E3DTR comparada à RMC e pela E2D comparada à E3DTR (Rc>0.90 and r>0.95; p<0.0001), assim como para a massa do VE, para os métodos E3DTR e RMC (Rc=0.96 e r=0.97; p<0.0001). Evidenciada maior exeqüibilidade da análise do MAS pela E3DTR. O índice geométrico do VE foi >0,15mmxm²xml-1 para todos os métodos. Observada correlação negativa entre o índice de dissincronia do VE e o percentual de fibrose miocárdica, sem significância estatística. CONCLUSÕES: A E3DTR é precisa e superior à E2D na avaliação da distribuição da hipertrofia miocárdica, quantificação dos volumes, função e massa ventricular esquerda em pacientes com CMH quando comparada à RMC, e parece ser superior na análise do MAS, pela melhor visão espacial da valva mitral.Todas as medidas do índice geométrico do ventrículo esquerdo estavam acima de 0,15mmxm²xml-1, compatível com CMH. Não foi identificada correlação entre o índice sistólico de dissincronia ventricular esquerda e a fibrose miocárdica. / INTRODUCTION: Real-time three-dimensional echocardiography (RT3D) has been demonstrated an accurate technique for the quantification of left ventricular (LV) volumes, ejection fraction (LVEF), and mass. In patients with hypertrophic cardiomyopathy (HCM), in which alterations of ventricular morphology are common, cardiac structural analysis is of utmost importance for guiding adequate therapy. Although magnetic resonance imaging (MRI) seems to have better definition for segmental analysis than two-dimensional echocardiography, (2D-E), it is considered a complex test with low availability and some limitations for use. METHODS: Comparative and double-blinded study in 20 patients with HCM. All patients underwent 2DE, RT3D and MRI within maximal interval of 6 months. Parameters analyzed by echocardiography and MRI included: wall thickness, LV volumes, systolic function, LV mass, systolic anterior motion of mitral valve, LV geometric index and LV dyssynchrony index. Statistical analysis was performed by Lin agreement coefficient, Pearson linear correlation and Bland-Altman model. RESULTS: Feasibility for measurements by MRI and echocardiography was 94%. There was good agreement and linear correlation between segmental analysis by echocardiography and MRI (Rc>0.84 and r>0.85; p<0.0001) and excellent correlation between 2DE and RT3DE (Rc=0.92 and r=0.92; p<0.0001). We also observed good agreement and linear correlation between RT3DE and MRI for ejection fraction (Rc=0.83 and r=0.93; p<0.0001) and excellent agreement and linear correlation between RT3DE and MRI for LV end diastolic volume and LV end systolic volume determinations (Rc>0.90 and r>0.95; p<0.0001) and mass (Rc=0.96 and r=0.97; p<0.0001). The feasibility for systolic anterior motion of mitral valve was higher by RT3DE (91%) than 2DE (64%). LV geometric index was >0.15 mmxm²xml-1 for all techniques. There was no correlation between LV dyssynchrony index and the percentage of myocardial fibrosis. CONCLUSIONS: RT3D is an accurate technique with superior performance than 2DE for the evaluation of myocardial hypertrophy localization, LV volume and functional determination as well as for LV mass assessment in patients with HCM in comparison with MRI. In addition, it seems to be superior for the analysis of systolic anterior motion due to its better spatial view of mitral valve. All measurements of LV geometric index were above the value of 0.15 mmxm²xml-1, and such findings are compatible with HCM. No correlation between LV dyssynchrony index by RT3D and the percentage of myocardial fibrosis determined by MRI was identified.
166

Avaliação prospectiva da função cardíaca sistólica e diastólica em pacientes com artrite idiopática juvenil pré e pós terapia anti-TNF / Prospective evaluation of systolic and diastolic heart function in juvenil idiopathic arthritis under anti-TNF

Alessandro Cavalcanti Lianza 04 December 2014 (has links)
INTRODUÇÃO: A artrite idiopática juvenil (AIJ) pode acometer o sistema cardiovascular em até 45% dos pacientes, principalmente nas formas mais graves. A insuficiência cardíaca congestiva ocorre em 3,9% dos adultos com artrite reumatoide (AR), havendo relatos em literatura da piora da função cardíaca em pacientes com AR em uso de terapia anti-TNF. Entretanto, não há dados em literatura sobre a segurança cardiovascular desta terapia em crianças. OBJETIVOS: Avaliação global da função cardíaca em pacientes com AIJ sob terapia anti-TNF. MÉTODOS: 25 pacientes com AIJ de curso poliarticular ativo e 22 indivíduos saudáveis foram submetidos a avaliação clínica e ecocardiográfica com Doppler convencional e tecidual e mensuração dos níveis dos biomarcadores cardíacos [própeptídeo natriurético N-terminal (NT-proBNP) e troponina T] no tempo basal (BL - préterapia anti-TNF). Os pacientes com AIJ foram avaliados a cada 3 meses por um período de 24 meses. RESULTADOS: Pacientes com AIJ e controles foram equivalentes em relação a idade (p=0,898) e gênero feminino (p=0,38). No BL, o tempo de relaxamento isovolumétrico (p=0,03), a velocidade da onda e\' no septo (p=0,014) e da onda S\' septal (p=0,03) foram significantemente reduzidos em pacientes com AIJ comparados a controles. As frequências dos níveis elevados de NT-proBNP e troponina T foram similares nesses dois grupos (p=0,297 e p=0,756), permanecendo dentro da normalidade durante toda a avaliação prospectiva, exceto por um paciente com elevação discreta da troponina T. Durante a terapêutica anti-TNF, nenhum dos 21 pacientes apresentou falência cardíaca, alteração da fração de ejeção e de outros parâmetros do Doppler. Só um paciente apresentou hipertensão pulmonar discreta. Avaliação adicional demonstrou que os pacientes com AIJ que apresentaram níveis elevados de NT-proBNP no BL tinham mais articulações ativas (p=0,025), VHS mais elevado (p=0,034) e maiores pontuações do JADAS-27 (p=0,014). CONCLUSÃO: Há segurança cardiovascular a longo prazo em pacientes com AIJ submetidos a terapia anti-TNF. Níveis elevados de NT-proBNP foi associado com atividade inflamatória na AIJ, reforçando uma interpretação mais cuidadosa deste biomarcador em pacientes com doença ativa / INTRODUCTION: Juvenile idiopathic arthritis (JIA) may cause heart damage in up to 45% of patients. Congestive cardiac failure may occur in 3,9% of adults with rheumatoid arthritis. It is described in literature, that some patients may presente with heart failure due to anti- TNF therapy. There is no data regarding cardiovascular safety in JIA patients. OBJECTIVE: To perform global assessment of long-term cardiac function in juvenile idiopathic arthritis (JIA) patients under TNF blockage therapy. METHODS: 25 polyarticular-course JIA patients pre-anti-TNF and 22 healthy controls underwent conventional/tissue Doppler echocardiography and cardiac biomarkers measurements [N-terminal pro-brain natriuretic peptide (NT-pro-BNP) and troponin T] at baseline (BL). Twenty-one JIA patients completed six evaluations during two consecutive years. Clinical/laboratorial evaluations were assessed before and during TNF blockage therapy. RESULTS: JIA patients and controls were comparable regarding current age (p=0.898) and female gender (p=0.38). At BL isovolumetric relaxation time of left ventricle (p=0.03), ventricular septum velocity (VS), E\' wave (p=0.014) and VS S wave (p=0.03) were significantly reduced in JIA patients compared to controls. Frequencies of elevated NT-pro-BNP and troponin T levels were similar in JIA and controls (p=0.297 and p=0.756) and levels remained within normal range throughout the study, except for one patient with mild troponin T elevation. During TNF blockage therapy, none of the 21 participants had heart failure, ejection fraction or other parameters alterations in conventional and tissue Doppler. Only one had mild pulmonary hypertension. Further analysis revealed that JIA patients with elevated levels of NT-pro-BNP at BL had significantly more active joints (p=0.025), higher ESR (p=0.034) and higher JADAS-27 (p=0.014). CONCLUSIONS: Long-term TNF blockage safety was demonstrated in JIA patients in spite of the observed subclinical diastolic involvement. Elevated cardiac biomarker in these patients was associated with inflammatory parameters reinforcing the need for a careful interpretation of this finding in patients with active disease
167

Contribution à l'étude de la circulation pulmonaire et de la fonction ventriculaire droite dans l'hypertension pulmonaire: apports de l'échocardiographie et de l'imagerie par Doppler tissulaire

Huez, Sandrine 31 January 2008 (has links)
Chapitre 1. Introduction<p><p>\ / Doctorat en sciences médicales / info:eu-repo/semantics/nonPublished
168

The diagnosis of Patent Foramen Ovale, its importance in migraine, and an insight into its genetic basis

Velupandian, Uma Maheshwari January 2012 (has links)
Background: Patent Foramen Ovale (PFO), a remnant of the foetal circulation, is emerging as a new cause of disease. It has been found to be associated with cryptogenic stroke in young adults, peripheral arterial embolism and neurological decompression sickness in divers. The detection of PFO remains a diagnostic challenge; transoesophageal echocardiogram being currently considered the ‘gold standard’. The development of a non-invasive technique is crucial for the identification of a venous-to-arterial shunt (v-aCS) which may permit paradoxical embolism. Little is known about the genetic basis of PFO and our limited knowledge is based on animal studies and gene mutations detected in patients with other cardiac septal defects. Methods: Study 1: PFO Detection and Evaluation: This study was designed to evaluate transcranial Doppler (TCD), transthoracic echocardiogram (TTE) and transoesophageal echocardiogram (TOE) with administration of contrast via arm and femoral veins. We then developed a standardized protocol for PFO detection and quantification using TCD. Study 2: PFO and Migraine: The PFO detection protocol developed from the first study formed the diagnostic technique to detect v-aCS in an adequately powered matched case control study to explore the association between PFO and migraine. Study 3: The Genetic basis of PFO: This study was designed to explore the genetic basis of a PFO using a candidate gene approach. Results: Study 1 - PFO Detection Study: When compared with TOE with femoral vein contrast injection as the ‘gold standard’, TCD with arm vein contrast was 100% sensitive and 97.4% specific for detecting a PFO. We defined a PFO positive (+ve) study on TCD as > 15 microbubbles entering the cerebral circulation, on TCD following arm vein injection and >16 microbubbles with a femoral contrast injection. A ‘major’ PFO+ve v-aCS was defined as >35 microbubbles with arm vein injection or >90 microbubbles with femoral vein injection. We then developed a new diagnostic pathway for PFO detection in clinical practice. Study 2 - PFO Migraine study: A significant difference in prevalence of v-aCS between migraine with aura M+A) and their matched controls was demonstrated with adjusted OR=3.72 (1.48-9.38) p=0.005 for a PFO+ve v-aCS, and a highly significant difference between M+A and controls for a ‘major’ PFO+ve v-aCS with adjusted OR = 6.38 (1.89 – 21.48) p = 0.003. There was significant association with APC resistance and migraine on thrombophilia screen. Study 3 - The PFO Genetics Study: This study detected mutations of GATA4 and NKX2-5 in both PFO+ve cases and PFO-ve controls. Two novel non synonymous mutations of GATA4, c.461T>A and c.994G>A were found only in PFO positive individuals and may be associated with a PFO. All the PFO+ve cases with a GATA4 gene mutation had a major PFO+ve v-aCSConclusion:TCD detects PFO with a sensitivity of 100% and specificity of 92.3% and is the most reliable non-invasive technique for PFO detection. When arm vein injections are used both cough and valsalva provocation is essential. There was a highly significant association between PFO+ve v- aCS and M+A, especially with a ‘major’ PFO+ve v-aCS. GATA 4 mutations though infrequent were found PFO+ve cases and all had major v-aCS.
169

Efeitos da adição de sinvastatina ao enalapril em indivíduos hipertensos com níveis de colesterol limítrofe e disfunção diastólica: um estudo aleatorizado, controlado, duplo-cego, com ecocardiograma e Doppler tecidual de repouso e estresse / Effect of the addition of simvastatin to enalapril in hypertensive individuals with average cholesterol levels and diastolic dysfunction: a randomized, placebo-controlled, double-blind trial, with ecochardiography and tissue Doppler of rest and stres

Adenalva Lima de Souza Beck 07 May 2010 (has links)
Introdução: Disfunção diastólica (DD) e diminuição da reserva contrátil do ventrículo esquerdo aumentam o risco cardiovascular de pacientes com hipertensão arterial sistêmica. As estatinas, pelos seus benefícios sobre a fibrose miocárdica, podem melhorar a função diastólica ou reserva contrátil de forma mais eficaz que inibidores da enzima de conversão da angiotensina (I-ECA) nesses pacientes. Objetivos: Investigar o efeito aditivo da estatina ao I-ECA na função diastólica e reserva contrátil de hipertensos com níveis de colesterol limítrofe. Métodos: Pacientes hipertensos com DD e LDL-colesterol < 160mg/dl submeteram-se a uma fase experimental para atingir pressão arterial sistólica (PAS) < 135mmHg e pressão arterial diastólica (PAD) < 85mmHg com enalapril ou enalapril e hidroclorotiazida. Quatro semanas após atingir o objetivo terapêutico, 55 pacientes foram aleatorizados para receber 80mg de sinvastatina (n = 27) ou placebo (n = 28) por um período de 20 semanas. Ecocardiograma de repouso e de estresse com dobutamina foram realizados antes e após o tratamento. O volume máximo do átrio esquerdo (VAE) foi medido pelo método biplanar de Simpson. Foram obtidas as velocidades de Doppler convencional e tecidual (DT) na diástole precoce (E, e) e diástole tardia (A, a) em repouso e durante estresse. As velocidades de DT foram a média dos 4 anéis mitrais basais. A reserva contrátil e a reserva diastólica do VE foram calculadas. A PA foi aferida mensalmente em consultório e o perfil lipídico foi dosado a cada 2 meses. Resultados: Após 20 semanas, a sinvastatina reduziu significativamente a PAS (-4±2mmHg; p=0,02), os níveis de colesterol total (-47±6 para estatina versus 6,2±5mg/dl para placebo; p<0,0001), LDL-colesterol (-41±5 para estatina versus 9,6±4mg/dl para placebo; p<0,0001) e triglicérides (-22,8±11,1 para estatina versus 15,3±8,3mg/dl para placebo; p<0,01). A razão E/A aumentou significativamente no grupo estatina (1,00±0,05 para 1,18±0,06 para estatina versus 1,06±0,05 para 1,06±0,04 para placebo; p=0,03), ao mesmo tempo em que o VAE reduziu significativamente neste grupo quando comparado ao placebo (24,5±0,9 para 21,1±0,8ml/m² para estatina versus 23,5±1,0 para 23,2±1,1ml/m² para placebo; p=0,048). A velocidade de e aumentou marginalmente no grupo estatina (9,6±0,6 para 10,2±0,5cm/s; p=0,05), mas sem diferença entre os grupos. A reserva contrátil aumentou significativamente em ambos os grupos (0,53±0,03 para 0,66± 0,05, p=0,009 para placebo versus 0,58±0,05 para 0,70±0,05, p=0,02 para estatina). Não houve correlação entre razão E/A, VAE e mudanças na pressão arterial ou níveis de colesterol. Houve uma moderada correlação positiva entre pressão arterial e LDL-colesterol (r=0,54; p=0,004). Conclusões: 1) A adição da sinvastatina ao enalapril melhora parâmetros de função diastólica em pacientes hipertensos com níveis de colesterol limítrofe, sendo este efeito independente da redução da pressão arterial ou do colesterol. 2) A PAS reduz com a sinvastatina, sendo esta redução correlacionada à redução do LDL-colesterol. 3) A reserva contrátil melhora com o tratamento com enalapril independente do uso da sinvastatina / Background: Diastolic dysfunction (DD) and decreased contractile reserve associated with hypertension are a surrogate for increased cardiovascular risk. Statins have experimental benefits on myocardial fibrosis, and could improve diastolic function or contractile reserve to a greater extend than ACE-inhibitors in hypertension. Objectives: Test in a double-blinded, placebo-controlled randomized study the effects of simvastatin added to enalapril treatment on DD and contractile reserve in hypertensive patients with average cholesterol levels. Methods: Hypertensive patients with DD and LDL-cholesterol < 160mg/dl underwent a run-in phase to achieve a systolic blood pressure (SBP) < 135mmHg and diastolic blood pressure (DBP) < 85mmHg with enalapril. Hydrochlorothiazide was added when need to achieve SBP or DBP control. Four weeks after reaching the optimum anti-hypertensive regimen, 55 patients were randomized to receive 80mg simvastatin (n = 27) or placebo (n = 28) for a period of 20 weeks. Transthoracic echocardiograms at rest and with dobutamine stress were performed before and after treatment. Left atrial volume (LAV) was measured by biplane modified Simpsons rule. Conventional mitral Doppler velocities were obtained at early diastole (E), late diastole (A) and E/A ratio was calculated, also Tissue Doppler velocities from mitral annulus (average from 4 basal walls) were measured at early diastole (e), late diastole (a) and systole (s); both at rest and during stress. The contractile and diastolic reserves were calculated at low dose of dobutamine stress. Blood pressure was measured monthly and lipid profile was analyzed every two months. Results: After 20 weeks, statin group showed a significant decrease in SBP (-4±2mmHg; p=0.02), total cholesterol (-47±6 for statin and 6.2±5mg/dl for placebo; p<0,0001), LDL-cholesterol (-41±5 for statin and 9.6±4mg/dl for placebo; p<0,0001) and tryglicerides levels (-22.8±11 for statin and 15.3±8mg/dl for placebo; p<0,01). E/A ratio increased significantly in statin group (1±0.05 to 1.18±0.06 for statin and 1,06±0,05 to 1,06±0,04 for placebo; p=0.03) at the same time that left atrial volume decreased (24.5±0.9 to 21.1±0.8ml/m² for statin and 23.5±1.0 to 23.2±1.1ml/m² for placebo; p=0.048). Moreover, e velocity had a trend to increase in statin (9.6±0.6 to 10.2±0.5cm/s; p=0.05) but there was no difference from placebo. Contractile reserve increased equally in both groups at lower dose of dobutamine (0.53±0.03 to 0.66±0.05, p=0.009 for placebo; 0.58±0.05 to 0.70±0.05, p=0.02 for statin). There was no correlation between E/A ratio, LAV and changes in blood pressure or cholesterol levels. There was a positive moderate correlation of blood pressure and LDL-cholesterol changes (r=0.54; p=0.004). Conclusions: 1) Simvastatin added to enalapril treatment in hypertensive patients with average cholesterol levels improves parameters of diastolic function independent of blood pressure or cholesterol changes. 2) Simvastatin decrease in SBP is correlated with LDL-cholesterol decrease. 3) Contractile reserve improves with hypertensive treatment irrespective to treatment with simvastatin
170

Sledování pohybu srdečního svalstva v ultrazvukovém záznamu / Speckle Tracking Echocardiography

Strecha, Juraj January 2015 (has links)
he thesis deals with proposal of an algorithm and implementation of a program that tracks a motion of the heart muscle in the captured ultrasound video of the heart. The point position estimation is calculated by optical flow method. The Active Shape Model method is used to confirm the accuracy of point's position tracking. The user annotates desired structure of the heart arch first and the application displays new points which represent a new deformed heart shape.

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