published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

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.

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

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.

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.

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.

No description available.

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.

Cette thèse présente les travaux réalisés en vue de l’élaboration d’un modèle cardiaque associant croissance, mouvement et circulation sanguine pour permettre ensuite la construction d’un modèle patient à partir d’un modèle de population. Le premier axe de ce travail est la simulation de la croissance bi-ventriculaire. Un modèle existant de surface unique, calculé à l’aide de méthodes statistiques, a été généralisé à un modèle bi-ventriculaire puis appliqué à la tétralogie de Fallot (ToF). Le deuxième axe concerne la modélisation du mouvement cardiaque au niveau de la population. Un modèle d’ordre réduit basé sur un modèle Polyaffine et LogDemons a été proposé. Il simule la dynamique cardiaque avec peu de paramètres. Les paramètres de transformation sont analysés par des méthodes statistiques. Un modèle de mouvement moyen a été calculé pour représenter le mouvement standard de la population. Le troisième axe s'intéresse à la simulation de l’écoulement sanguin à l’échelle de la population. La complexité des simulations spécifiques à un patient a été réduite grâce à l’utilisation de méthodes d’analyse d’image, de dynamique des fluides numérique et de réduction d’ordre de modèle. La simulation du flux sanguin dans l’artère pulmonaire pour des patients ToF a permis de mieux comprendre l’impact du sang régurgité sur la pression et la vitesse. Étant donné nos contributions sur ces trois axes, nous sommes maintenant en bonne position pour élaborer le modèle couplé des contributions interdépendantes de la croissance, du mouvement et de l'écoulement sanguin. Ce modèle pourrait être utilisé afin d'aider la planification de la thérapie chez les patients atteints de maladies cardiaques. / This thesis presents work towards a coupled model of cardiac growth, motion, and blood flow to enable predictive patient-specific models to be built from a population-based model. The first axis of this work is to simulate bi-ventricular growth through aging. A previously proposed single surface model computed using statistical methods was extended to a bi-ventricular model and applied to Tetralogy of Fallot patients to model the complex evolution of the ventricles due to the pathology. The second axis concerns the development of a model to simulate cardiac motion at a population level. A reduced-order cardiac-specific motion model was proposed to simulate the motion dynamics with a small number of parameters using a Polyaffine and LogDemons based model. From the computed transformations, the parameters were analysed using statistical methods to obtain population-based measures of normality. A mean motion model was derived to represent the normal motion for a given population. The third axis is to develop a model of population-based flow dynamics. The complexity of patient-specific simulations was reduced by combining image analysis, computational fluid dynamics and model order reduction techniques. Blood flow through the pulmonary artery in Tetralogy of Fallot patients was simulated to better understand the impact of regurgitated blood on pressure and velocity. Given our contributions on these three axes, we are now in a good position to couple the models in order to capture the interrelated contributions of growth, motion and flow. Such a model could be used to aid in therapy planning and decision making for patients with heart disease.

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.