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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

Familial Inheritance in Congenital Heart Disease: A Focus on Tetralogy of Fallot

Swaby, Jodi-Ann 20 December 2011 (has links)
Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease (CHD). The understanding of the genetics and inheritance of TOF is limited. Although about 15% of cases are associated with a 22q11.2 deletion, the majority have no known aetiology. Even in 22q11.2 Deletion Syndrome (22q11DS), factors that increase the likelihood of CHD expression are poorly understood. We aimed to determine the prevalence and phenotypes of CHD in relatives of adults with TOF. We also investigated the prevalence of CHD in relatives without a 22q11.2 deletion of individuals with 22q11DS. Offspring of patients with TOF had the greatest prevalence of CHD. Diverse cardiac phenotypes, including left heart obstructive lesions, were found in families. We also found that unaffected relatives of individuals with 22q11DS had a greater prevalence of complex CHD over population expectations, suggesting that modifier genetic factors may be involved in expression of CHD in 22q11DS.
22

The quantitative analysis of the flow in pulmonary artery of Tetralogy of Fallot patients

Chen, Shin-Jhih 18 July 2012 (has links)
Magnetic Resonance Imaging (MRI) provides noninvasive method in clinical application. For the patients of Tetralogy of Fallot underwent surgical correction,regurgitation and turbulence in blood flow may still present in pulmonary arteries.In this study,Phase Contrast MR Imaging will be used to quantitate,and to observe blood flow in after repair Tetralogy of Fallot (TOF) patients.We use 3 parameters,which are Coefficient of Variance (CV),Regurgitant Fraction (RF) and Net Flow analysis to analyze two situations of blood flow in patients¡¦ left pulmonary artery ¡Bright pulmonary artery and main pulmonary artery.We also compare normal subjects to patients in this experiment. The pulmonary circulation is the action of blood flow from right ventricular to main pulmonary artery then to left pulmonary artery and right pulmonary artery. We use three additional parameters: rPA / lPA flow ratio¡BPeak Velocities and Total Flow to observe the pulmonary blood flow. We use rPA / lPA flow ratio to identify the tendency of blood flow, with Peak Velocities to find out Peak Velocity in normal difference between patient.Meanwhile, the measurement of Total Flow is applied to observe the flow from main pulmonary artery to left and right pulmonary artery. We hope to use these parameters that can help doctors on clinical diagnosis.
23

The quantitative analysis of in-plane flow speed in branch pulmonary arteries after repair of tetralogy of Fallot: A phase-contrast MR imaging study.

Niu, Sheng-chun 17 July 2006 (has links)
Recently magnetic resonance imaging has become more and more popular in clinical applications. In clinical studies, the heart of the TOF patient has some congenital defects. These defects lead to insufficient blood flowing into the pulmonary arteries, rendering the necessary of repair for TOF patients. However, even after repair, the blood in pulmonary arteries still cannot flow in the same way with those of normal people. For this reason, studies on the flow behavior of pulmonary arteries in TOF patients would be valuable in clinical applications. In this study, we focus on the quantitative analysis of in-plane flow in branch pulmonary arteries (left and right pulmonary arteries) after repair of tetralogy of Fallot (TOF) by means of phase-contrast MR imaging. The regurgitation and turbulence were evaluated by coefficient of variance (CV) and regurgitant fraction. Vector map of in-plane flow was also included in order to facilitate the observation of flow patterns. Our result shows a positive correlation of CV and regurgitant fraction in terms of turbulence and regurgitation. Therefore, we conclude that CV and regurgitant fraction as well as vector maps may be helpful to quantitate in-plane flow for after repair of TOF patients, providing a more accurate analysis in clinical diagnosis.
24

Vortical flow pattern analysis in pulmonary arteries after repair of tetralogy of Fallot using phase-contrast MR imaging

Yang, Tsung-Yu 18 July 2008 (has links)
Magnetic resonance imaging (MRI) is an useful technique that provides a noninvasive method in clinical applications. For the patient of tetralogy of Fallot (TOF) after repaired, turbulence and regurgitation in blood flow may appear in pulmonary arteries. In this study, phase contrast MR imaging was applied and vortical flow patterns in the pulmonary arteries of patients after repair of TOF has been investigated. There are two major part of this study. Firstly we simulated vortical flow patterns of star, focus, and saddle which are most frequently appeared in blood flow. Quadrant index has been proposed for pattern analysis. In the second part we applied these parameters to in vivo data of repaired TOF patients, and compared with other parameters such as vorticity, coefficient of variance (CV), and regurgitant fraction (RF). Our result shows that the linear correlation between the mean of CV of velocity and mean of CV of vorticity in right pulmonary artery (RPA) as well as pulmonary trunk (PT) is larger than that in left pulmonary artery (LPA). This study shows that vorticity may provide some useful information of flow patterns and therefore helps doctors in clinical diagnosis
25

Relation between plasma brain natriuretic peptide, right ventricular function and exercise capacity in patients after surgical repair ofTetralogy of Fallot

Cheung, Wai-yin, Eddie, 張蔚賢. January 2005 (has links)
published_or_final_version / Medical Sciences / Master / Master of Medical Sciences
26

Untersuchung des Connexin 43 und N-Cadherin bei Patienten mit Fallot’scher Tetralogie und Double Outlet Right Ventricle vom Fallot-Typ

Haunschild, Josephina 04 January 2016 (has links) (PDF)
In der vorliegenden Arbeit wurden Myokardproben des rechtsventrikulären Ausflusstraktes von Patienten mit Fallot’scher Tetralogie sowie Double Outlet Right Ventricle vom Fallot - Typ untersucht. Hintergrund der Studie waren Untersuchungen anderer Autoren an Cx43 - knock - out Mäusen, die dort Veränderungen des kardialen Phänotyps beschrieben, die sie als Fallot - artig interpretierten. Daraus wurde die Hypothese entwickelt, dass Änderungen auf der Ebene des Connexin 43 ursächlich mit der Fallot’schen Tetralogie verbunden sein könnten. Es erfolgte eine histologische Analyse von 25 Patientenproben im Hinblick auf die Lokalisation von Connexin 43 sowie N - Cadherin. Es zeigte sich eine altersabhängige Verteilung von Connexin 43 und N - Cadherin. Insbesondere Patienten der Gruppe 1 (jünger als zwei Jahre) zeigten eine Verteilung sowohl an der lateralen Zellseite, als auch am Pol der Kardiomyozyten. Mit zunehmendem Alter beschränkten sich sowohl Connexin 43 als auch N - Cadherin auf die Disci intercalares zwischen den Kardiomyozyten und befanden sich dort in enger Nachbarschaft zueinander. Des Weiteren erfolgte eine Analyse der codierenden Region des Connexin 43 Gens mittels High Resolution Melting - PCR und sich daran anschließender Sequenzierung. Es zeigten sich sowohl bei den Kontrollen als auch den Patienten bereits bekannte Single Nucleotide Polymorphismen sowie bis dato unbekannte Sequenzvariationen. Allerdings wurden keine homozygoten Veränderungen der DNA festgestellt. Auch fand sich keine der heterozygoten Veränderungen in allen untersuchten Patienten. Somit ist es unwahrscheinlich, dass ein einzelner Basenaustausch zum komplexen Krankheitsbild der Fallot’schen Tetralogie beziehungsweise zum Double Outlet Right Ventricle vom Fallot - Typ führt.
27

Parâmetros ecocardiográficos e peptídeo natriurético cerebral em pacientes no pósoperatório tardio de tetralogia de Fallot / Echocardiographic parameters and brain natriuretic peptide in patients after surgical repair of tetralogy of Fallot

Tatani, Solange Bernardes [UNIFESP] 30 September 2009 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:50:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-09-30. Added 1 bitstream(s) on 2015-08-11T03:25:31Z : No. of bitstreams: 1 Publico-00388.pdf: 783398 bytes, checksum: 5ad5aa9fa9c1b1087f37cc5d3c15b281 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Introdução e objetivos: as disfunções sistólica e diastólica do ventrículo direito, secundárias às lesões residuais após a correção cirúrgica da tetralogia de Fallot, contribuem para a morbidade e mortalidade no pós-operatório tardio. Embora estas lesões residuais possam ser avaliadas pela ecocardiografia Doppler, a relação entre os parâmetros ecocardiográficos e os níveis de proBNP (fragmento N-terminal do pró- BNP), um potencial biomarcador de sobrecarga ventricular direita, ainda não está bem estabelecida. Os objetivos do estudo foram analisar, em pacientes no pós-operatório de tetralogia de Fallot, a relação dos níveis plasmáticos de proBNP com parâmetros ecocardiográficos das dimensões das cavidades cardíacas direitas e da gravidade das lesões residuais, e os possíveis marcadores ecocardiográficos de níveis elevados de proBNP. Métodos: os níveis séricos de proBNP e os parâmetros ecocardiográficos foram obtidos no mesmo dia em 49 pacientes no pós-operatório tardio de tetralogia de Fallot (idade média de 14,7 anos, 51% do sexo feminino, com tempo médio de pós-operatório de 9,5 anos). Os parâmetros Doppler ecocardiográficos analisados foram: dimensões do átrio e ventrículo direitos, funções sistólica e diastólica ventricular direita e lesões pulmonares residuais. A relação entre estas variáveis e os níveis de proBNP foi analisada com testes de correlação de Pearson e análises uni e multivariada. Os valores de corte dos parâmetros ecocardiográficos preditores de níveis elevados de proBNP foram analisados pela curva ROC. Resultados: os níveis de proBNP estavam elevados em 53% dos pacientes e correlacionaram-se com o diâmetro diastólico do ventrículo direito (r= 0,41; p=0,003), com diâmetros longitudinal (r= 0,52; p=0,0001) e transversal (r= 0,47; p=0,001) do átrio direito, com o tempo de me0,41; p=0,005) e com o índice do refluxo pulmonar (r= -0,60; p<0,001). Pela análise multivariada o índice do refluxo pulmonar (R= -597; p=0,001; IC: -913,2 a -280,8) e o diâmetro longitudinal do átrio direito (R= 7,74, p<0,001; IC: 4,18 a 11,31) foram preditores independentes de proBNP elevado. Tempo de meia-pressão menor que 64 ms e índice do refluxo pulmonar menor que 0,65 apresentaram a melhor acurácia para indicar proBNP elevado. Conclusões: os níveis de proBNP podem estar elevados no pós-operatório tardio de tetralogia de Fallot e correlacionaram-se com as dimensões das câmaras direitas e com a gravidade do refluxo pulmonar. Valores de corte das dimensões das câmaras direitas e dos índices de gravidade do refluxo pulmonar podem se constituir em parâmetros úteis no seguimento dos pacientes no pós-operatório tardio de tetralogia de Fallot com lesão residual.ia-pressão da curva de velocidade do refluxo pulmonar (r= - / Background: Although the residual lesions after surgical correction of tetralogy of Fallot (TOF) can be evaluated by Doppler echocardiography (DE), the relation of DE parameters with the proBNP level, a potential biomarker of right ventricle overload, is not well known. The objective this study was to evaluate the DE parameters and their relation to proBNP levels. Methods: proBNP plasma level and Doppler echocardiography parameters were obtained in the same day in 49 patients later after repair of TOF (mean age of 14.7 years, 51% female, mean PO time of 9.5 years). The DE parameters studied were the dimensions of the right atrium (RA) and ventricle (RV), RV diastolic and systolic function and residual pulmonary lesions. The relation between them and proBNP levels were analyzed and the cutoff values of DE parameters for elevated proBNP determined. Results: proBNP was elevated in 53% and correlated with RV diastolic diameter (r=0.41; p=0.003), RA longitudinal (r=0.52; p=0.0001) and transversal (r=0.47; p=0.001) diameters, pressure half time of pulmonary regurgitation (PR) velocity (PHT) (r= -0.42; p=0.005) and the PR index (r=-0.60; p<0.001). By multivariate analysis the PR index (r=-597; p=0,001; CI: -913.2 to –280.8) and RA longitudinal (r=7.74; p<0,001; CI 4.18 to 11.31) were independent predictors of elevated proBNP. PHT lower than 64 ms (0.76) and PRi lower than 0.65 (0.81) had the best accuracy for elevated proBNP. Conclusion: proBNP may be increased in patients after surgical repair of TOF, correlated with the size of right cardiac chambers and the severity of PR. / TEDE / BV UNIFESP: Teses e dissertações
28

Mécanismes arythmogènes dans le ventricule droit sain et dans la dysfonction ventriculaire droite / Arrhythmic mechanisms in the healthy right ventricle and in RV dysfunction

Dubes, Virginie 29 April 2016 (has links)
Le ventricule droit (VD) possède une embryogénèse, une géométrie et despropriétés biomécaniques différentes du ventricule gauche (VG). L’infundibulum pulmonaire(RVOT) est une origine fréquente d’arythmies dans le VD sain ou pathologique. La tétralogiede Fallot (TOF) est la cardiopathie congénitale cyanogène la plus fréquente et est associée àune dysfonction du VD. Si la correction chirurgicale a augmenté l’espérance de vie despatients TOF, à l’âge adulte les séquelles chirurgicales du VD et RVOT conduisent souvent àune insuffisance cardiaque, des arythmies voire la mort subite cardiaque. Les objectifs decette thèse sont de : (i) définir les propriétés électrophysiologiques et structurelles du VDsain chez le cochon et (ii) caractériser le remodelage arythmogène des ventricules dans unmodèle porcin de réparation de TOF (rTOF). Nous avons démontré la présence d’unehétérogénéité de repolarisation et de conduction dans le VD sain en lien avec un profild’expression spécifique des canaux ioniques dans le RVOT sub-épicardique. Une approchehistologique a également permis de mettre en évidence une structure tissulaire spécifique auRVOT contribuant au ralentissement de l’activation de cette région. Les coeurs des cochonsrTOF témoignent d’un remodelage électrophysiologique et structurel pro-arythmique du VDcaractérisé par une dispersion de la repolarisation, et un ralentissement de la conductioncorrélé à un remodelage moléculaire et structurel. Nous décrivons également la présenced’un remodelage arythmogène distinct dans le VG rTOF sur le plan électrique et structurelsans modification des propriétés hémodynamiques. En conclusion, ces travaux révèlent laprésence de substrats arythmogènes du VD sain et un profond remodelage pro-arythmiquedans les ventricules rTOF. / The right ventricle (RV) has different embryologic history, geometry andbiomechanics properties compared to the left ventricle (LV). The right ventricular outflow tract(RVOT) is a common arrhythmia origin in the healthy or pathological RV. Tetralogy of Fallot(TOF) is the most frequent cyanotic congenital heart disease and is associated with RVdysfunction. Surgical correction has significantly increased patient’s life expectancy butsurgical lesions often lead to heart failure, arrhythmias even sudden cardiac death inadulthood. The aims of this work are to: (i) define RVOT electrophysiological and structuralproperties in the healthy pig and (ii) characterize a potential arrhythmogenic remodeling inboth ventricles in a porcine model mimicking repaired TOF (rTOF). We showed the presenceof repolarization and conduction heterogeneities in the healthy RV in relation to a specific ionchannel expression profile in the RVOT epicardium. Moreover, an histological approachhighlighted the presence of a specific tissue structure likely to contribute to the slowconduction observed in this region. A pro-arrhythmic electrophysiological and structuralremodeling was found in the RV of rTOF pigs. This remodeling was characterized by anincreased dispersion of repolarization and slower conduction properties which were linked toa molecular and structural remodeling. Interestingly, we also described a distinct electricaland structural arrhythmogenic remodeling in the rTOF LV in the absence of hemodynamicalteration. To conclude, this work revealed the presence of an arrhythmogenic substratewithin the healthy RV and a profound arrhythmogenic remodeling of both ventricles in rTOF.
29

Novel insights into arrhythmogenesis from the right ventricular outflow tract and tetralogy of Fallot

Schneider, Heiko January 2015 (has links)
Background: The right ventricular outflow tract (RVOT) is known to be the origin of potentially dangerous ventricular tachycardias (VT). Arrhythmias can occur in what are otherwise assume to be structurally normal hearts as well as in arrhythmia syndromes like Brugada syndrome, catecholaminergic polymorphic VT and arrhythmogenic right ventricular dysplasia. In adults with surgically corrected tetralogy of Fallot (ToF), VT often originates in the RVOT. Methods: To investigate potential arrhythmia substrates in the structurally normal heart, the RVOT of adult rats was investigated and compared to the right ventricle (RV). In the human, the right atrium (RA), RV and the RVOT were examined in patients free of electrical and structural disease at the time of clinically indicated surgery on the left heart. The same tissue samples were collected from adults with surgically corrected ToF at the time of pulmonary valve replacement. Real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to explore changes on the mRNA level. Antibody based techniques (immunohistochemistry and Western blot) and mass spectrometry were used to identify changes on the protein level. In the rat RVOT, fine microelectrodes were employed to investigate electrophysiological characteristics. Results: A reduction in the Na+ channel Nav1.5 was found in the structurally normal RVOT in the rat and human. In the rat, RVOT-nodal like myocytes were identified. Unlike ventricular myocytes, the myocytes did not express the gap junction channel Cx43 and the K+ channel Kir2.1, but they did express the pacemaker Ca2+ channel Cav3.2 and the transcription factor Tbx3. Ectopic pacemaker and nodal-like action potentials with phase 4 depolarization were recorded from the region of the pulmonary valve. In the RA of ToF patients, SERCA2A was found to be downregulated (mRNA and protein) as seen in heart failure and atrial fibrillation. Further widespread remodelling was found in the RA, the RV and RVOT identifying multiple changes as seen in heart failure with downregulation of K+ channels and β-receptors and an increase in inflammatory markers and extracellular matrix molecules. Multiple molecules involved in the mitochondrial respiration chain were found to be downregulated in the RVOT of ToF patients. Conclusion: This is the first study that demonstrates reduction in Nav1.5 in the RVOT of structurally normal human hearts. The changes found in the rat RVOT could explain why arrhythmias originate in the RVOT. The widespread remodelling in ToF, especially in the ECM, could form a substrate for reentry arrhythmias. Mitochondrial dysfunction could point towards potential treatment targets for heart failure in this patient group.
30

Monitoramento do propranolol em crianças submetidas a correção cirúrgica da Tetralogia de Fallot através de cromatografia líquida de alta eficiência: fluorescência / Therapeutical propranolol monitoring in childrens with Fallot tetralogy during cirurgical correction by high performance liquid chromatography fluorescence

Sanches, Cristina 09 April 2007 (has links)
O objetivo do presente trabalho foi validar micrométodo simples e sensível para a quantificação do propranolol em plasma utilizando CLAE-F com a finalidade de aplicação no monitoramento das concentrações de propranolol durante o washout. Necessitou-se apenas de 200&#181;L de plasma. Os tempos de retenção para o fármaco e o padrão interno (verapamil) foram 8,4 e 17,5min, respectivamente, utilizando coluna de fase reversa C18, (150 x 6mm, 5micra) e fase móvel consistindo de tampão acetato 0,1M, pH5,0 e acetonitrila (60:40, v/v), 0,7 mL/min, detecção 290nm (Ex) e 358nm (Em) em sistema isocrático de eluição. A validação deste método analítico avaliada através dos limites de confiança apresentou sensibilidade de 0,02 ng/mL (LD), linearidade na faixa compreendida entre 0,05 -1000ng/mL e 4,7% e 8,6% para precisão intra- e inter-dias, respectivamente. Observou-se, também, boa exatidão e alta seletividade para este método. Concluindo, o método analítico apresentado para a quantificação do propranolol mostrou elevada sensibilidade para quantificação do propranolol. Após a última dose pré-operatória, as concentrações plasmáticas do propranolol normalizadas com o hematócrito de seis pacientes pediátricos, expressas através das medianas, foram: 7,09 ng/mL no início da cirurgia, 2,69 ng/mL no inicio da CEC, 1,14 ng/mL intra- CEC, 2,79 ng/mL no pós-CEC, e 2,70 ng/mL no final da cirurgia. No pós-operatório tardio, registraram-se as medianas 0,63 ng/mL no primeiro PO e 0,03 ng/mL no segundo PO. Registrou-se declinio de 7,09 para 2,70 (p<0,05) da concentração de propranolol (normalizada) do início da cirurgia comparado ao inicio da CEC. Apesar do prolongado tempo de residência média (MRT) de 35,8 h as concentrações do propranolol mostraram redução significativa do primeiro PO para o segundo PO, indicando que restaurada a redistribuição, a eliminação foi completa. / The objective of the present study was to develop a simple and sensitive micromethod for the quantification of propranolol in plasma using HPLC-fluorescence for drug plasma concentration monitoring during the washout. Only 200&#181;L of biological sample was necessary. The retention times of the drug and its internal standard (verapamil) were 8.4 and 17.5 min, respectively, using a C18 reverse-phase column and a mobile phase consisting of 0.1 M acetate buffer, pH 5.0, and acetonitrile (60:40, v;/v), with detection at &#955;ex 290 nm and &#955;em 358 nm in an isocratic elution system. Validation of this analytical method showed that it was highly sensitive, with a detection limit of 0.02 ng/ml, linearity in the range of 0.05 to 1000 ng/mL, and intra- and inter-day precision of 4.7 and 8.6%, respectively. In addition, the method showed good accuracy and high selectivity. Analytical method validated showed high sensitivity for the quantification of propranolol; then this method was applied to quantify propranolol in plasma of children during the surgery for correction of tetralogy of Fallot including a followup at the first and second days of the intervention. The plasma propranolol concentrations, hematocrit normalized, after the last preoperative dose, expressed as medians, were: 7.09 ng/mL at the beginning of surgery, 2.69 ng/mL at the beginning of cardiopulmonary bypass (CPB), 1,14 ng/mL during CPB, 2,79 ng/mL after CPB, and 2.70 ng/mL at the end of surgery. Median of late postoperative propranolol concentrations were 0,63 ng/mL on postoperative day 1 and 0.03 ng/mL on day 2. A significant decline on the normalized propranolol concentration was observed between the beginning of surgery and the beginning of CPB. In addition, in spite of the prolonged mean residence time of 35.8 hours, the propranolol concentrations decreased significantly at the postoperative period on day 1 up to day 2, indicating that, once the redistribution is restored, the washout of drug was completed.

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