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Functional Analysis of KLF13 in the HeartDarwich, Rami January 2016 (has links)
Congenital heart defects (CHD) are the largest class of birth defects in humans and are a major cause of infant mortality and morbidity. Deciphering the molecular and genetic etiologies central for heart development and the pathogenesis of congenital heart diseases (CHD) is a challenging puzzle. We have previously demonstrated that the zinc-finger kruppel-like transcription factor KLF13, expressed predominantly in the atria, binds evolutionarily conserved regulatory elements known as CACC-boxes and transcriptionally activates several cardiac promoters. KLF13 loss of function in Xenopus embryos was associated with cardiac developmental defects underscoring its critical role in the heart. In the current study, using in vivo and in vitro approaches, we examined KLF13’s mechanisms of action and its interaction with other cardiac regulators. To test the evolutionary conserved role in the mammalian heart, we deleted the Klf13 gene in transgenic mice using homologous recombination. Mice with homozygote deletion of Klf13 were born at reduced frequency owing to severe heart defects. We also report the existence of a novel isoform of KLF13, referred to here as KLF13b. Furthermore, we report that KLF13 interacts biochemically and genetically with the T-box transcription factor TBX5 which is a key regulator of heart development. Our data provide novel insight into the role of KLF13 in cardiac transcription and suggest that KLF13 maybe a genetic modifier of congenital heart disease. Furthering our knowledge of protein-protein interactions and gene transcription will enhance genotype-phenotype correlation and contribute to better understanding of the etiology of CHD.
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Gata6 Haploinsufficiency Leads to Aortic Valve, Conduction System and Limbs DefectsGharibeh, Lara 03 May 2018 (has links)
Cardiovascular diseases are the leading cause of morbidity and mortality worldwide. Congenital heart disease (CHD) is a risk factor for premature cardiovascular complications. Great advances have occurred in the past years leading to the identification of several genes essential for proper cardiac formation such as GATA4/5/6 mutated in some individuals with CHD. GATA6 is a zinc finger transcription factor whose presence is crucial for early embryonic development. GATA6 is expressed in many cell types of the heart including myocardial, endocardial, neural crest, and vascular smooth muscle. In human, mutations in GATA6 result in variable cardiac phenotypes. The objective of this thesis was to determine the roles that GATA6 play in the different cell types of the heart and to elucidate the molecular basis of the cardiac defects associated with Gata6 haploinsufficiency. For this, a combination of cell and molecular techniques were used in vitro and in vivo. First, we show that Gata6 heterozygozity leads to RL-type bicuspid aortic valve (BAV)- the most common CHD affecting 2% of the population. GATA6-dependent BAV is the result of disruption of valve remodeling and extracellular matrix composition in Gata6 haploinsufficient mice. Cell-specific inactivation of one Gata6 allele from Isl-1 positive cells, but not from endothelial or neural crest cells, recapitulates the phenotype of Gata6 heterozygous mice revealing an essential role for GATA6 in secondary heart field myocytes during valvulogenesis. We further uncovered a role for GATA6 as an important regulator of the cardiac conduction system and revealed that GATA6 expression regulates the activity of the cardiac pacemaker. GATA6 exerts its role via regulation of the cross-talk among the different cell types of the SAN. Lastly, some CHDs are characterized by abnormalities of both the limbs and the heart such as the Holt Oram syndrome (caused by mutation in TBX5 transcription factor). The molecular basis for limb-heart defects remain poorly understood. In the course of this work, we discovered that Gata6 haploinsufficiency resulted in a partially penetrant polysyndactyly (extra digits fused together) phenotype. Together, the data provide novel molecular and cellular insight into GATA6 role in normal and pathologic heat development. Our results also suggest that GATA6 should be added to the list of genes whose mutations are potentially associated with heart and limb abnormalities. Better knowledge of the molecular basis of CHD is a prerequisite for the development of diagnostic and therapeutic strategies to improve care of individuals with congenital heart disease.
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Cognitive, motor, and autonomic function in infants with complex congenital heart diseases, infants born preterm, and infants born full-termChen , Chao-Ying January 2014 (has links)
No description available.
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Perioperative Antibiotikaprophylaxe bei angeborenen HerzfehlernBoschnakow, Anett 19 April 2002 (has links)
In den letzten Jahren haben sich die Empfehlungen für eine Antibiotikaprophylaxe in der Herzchirurgie bezüglich Antibiotikawahl und Applikationsdauer verändert und gehen nicht speziell auf die Kinderherzchirurgie ein. Im Deutschen Herzzentrum Berlin wurde seit 1988 bei Operationen aufgrund angeborener Herzfehler die Kombinationsprophylaxe mit Piperacillin und Cefotaxim angewandt. Neue internationale Empfehlungen schlagen jedoch ein Cephalosporin der I. oder II. Generation vor. Fragestellung dieser prospektiven Beobachtungsstudie ist deshalb, ob eine Umstellung der im DHZB üblichen Kombinationsprophylaxe auf eine Monoprophylaxe mit Cefotiam gerechtfertigt ist. Vom 1.3. - 31.8. 1995 wurden 180 Patienten mit Operationen am offenen Herzen in die Studie eingeschlossen. 99 Patienten erhielten die bisher im DHZB etablierte Kombinationsprophylaxe mit Cefotaxim und Piperacillin (Cx/P-Gruppe). 81 Patienten bekamen eine Monoprophylaxe mit Cefotiam (Ct-Gruppe). Die postoperative Infektionsrate betrug in der Ct-Gruppe 14,8 % und in der Cx/P-Gruppe 17,2 %. Die Prophylaxe erfolgte für beide Gruppen durchschnittlich 103 Stunden bzw. 110 Stunden. Die Studie konnte aufgrund geringer Patientenanzahl aus statistischer Sicht keinen Beweis für einen Unterschied erbringen. Dafür zeigte die Metaanalyse, daß auch bei einer großen Patientenanzahl (n=4177) kein statistischer Unterschied zwischen einer Schmalspektrum- und einer Breitspektrumprophylaxe besteht. Es wurde ferner gezeigt, daß Cefotiam den Anforderungen einer effektiven Prophylaxe gerecht wird und Vorteile gegenüber der Kombinationsprophylaxe aufweist. Die Studie hat dazu beigetragen, daß seit 1996 in der Kinderherzchirurgie im DHZB eine Monoprophylaxe mit einem Cephalosporin der I. Generation - Cefazolin - durchgeführt wird und hat weiterhin eine Verkürzung der Prophylaxedauer bewirkt. / Perioperative antibiotic prophylaxis for patients with congenital heart diseases Recommendations for antimicrobial prophylaxis regarding the choice of antibiotics and the application time have changed and do not include cardiac surgery for infants. A combination of piperacillin and cefotaxim has been used since 1988 in the German Heart Institute of Berlin. Updated recommendation now propose the use of a I. or II. generation cephalosporin. The purpose of this prospective study was to evaluate whether a change from the so long used combined prophylaxis towards a monoprophylaxis with cefotiam is justified. From 1st of March until 31st of August 1995 a total number of 180 patients with an open heart surgery were included into the study. 99 patients received a combination with cefotaxim and piperacillin (cx/p-group), which was the standard combination in the German Heart Institute of Berlin. 81 patients received a monoprophylaxis with cefotiam (ct-group). The postoperative rate of infections was 14,8 % in the ct-group and 17,2 % in the cx/p-group. For both groups the duration of prophylaxis was on average 103 respectively 110 hours. Due to a relatively small number of patients the study could not show a statistically significant difference between both prophylactic regimes. The performed meta-analysis comparing the postoperative infections in small spectrum and broad spectrum prophylaxis in the open heart surgery did not find a significant difference in a large group of patients (n=4177). Our study supports the fact, that cefotiam meets the criteria of an effective antibiotic prophylaxis and has additional benefits compared to the combined prophylaxis scheme. The results of this study have led to a replacement of the old perioperative prophylaxis regime by cefotiam for open heart surgery for infants in the German Heart Institute of Berlin since 1996 and have led to a reduction of the application time during the prophylaxis.
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Avaliação dos motivos de referenciamento ao ambulatório de cardiologia pediátrica da Policlínica Municipal de Sorocaba pela atenção primária: criação de proposta de interação educacional em serviçoGuevara, Virna Maria 29 October 2014 (has links)
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Previous issue date: 2014-10-29 / Introduction- The prevalence of congenital cardiovascular disease is of 7 to 10
children in every 1000 live births. The reasons that lead to the referral of a child by
primary care physicians are very varied, with cardiac heart murmur being the most
common. Amongst other reasons one can find precordial pain, arrhythmia, fatigue,
dyspnea, cyanosis, abnormal chest x-ray, abnormal electrocardiogram, medical
examination for physical exercise. The present challenge for pediatricians, family
physicians and pediatric cardiologists is to develop accurate diagnosis strategies in a
cost-effective manner, with the aim of improving the treatment and save resources.
Objectives- The objective is to strengthen the network of health care in its primary
and secondary levels using cases of Pediatric Cardiology as the strategic condition
and develop an interdisciplinary work proposal with the support of a matrix, which
optimize the referral system. Material and methods- It is about the exploratory study
with descriptive documental analysis from 433 referral letters of patients seen at the
Pediatric Cardiology Ambulatory of Policlinic of Sorocaba from January to June 2012,
along with the study of the patients medical records. The data collected is quantified
using descriptive statistics when relevant. Results- One hundred and sixty-six
patients (38,3%) were discharged, 93 with feedback letter of referral (56,0%). Ninetysix
(22,2%) missing follow up, 9 of which had confirmed cardiovascular disease, 29
with absence of cardiovascular disease and 58 without a definitive diagnosis of
cardiovascular disease. One hundred and seventy-one patients (39,5%) attend
follow-ups. Conclusion- With the aim of strengthening the network of health care
using recent medical advances, such as telemedicine and the concept of matrix
support, as means of exchange, improvement and to save resources and knowledge / Introdução - A prevalência das cardiopatias congênitas está entre sete a dez
crianças por 1000 nascidas vivas. Os motivos que levam o médico da atenção
primária a encaminhar uma criança ao cardiologista pediátrico são bastante
variados, sendo o sopro cardíaco a causa mais frequente. Dentre outros motivos
frequentes encontram-se dor precordial, arritmias, cansaço, dispneia, cianose,
radiografia de tórax anormal, eletrocardiograma alterado, avaliação para atividade
física. O desafio atual dos pediatras, médicos de família e cardiopediatras é
desenvolver estratégias de diagnósticos precisos e financeiramente adequados, com
o intuito de melhorar o tratamento e racionalizar os recursos. Objetivos - O objetivo
é fortalecer a rede de atenção à saúde em seus níveis primário e secundário,
utilizando-se dos casos de Cardiologia Pediátrica como condição estratégica e
desenvolver uma proposta de trabalho interdisciplinar e de interação com apoio
matricial, otimizando o sistema de referência e contrarreferência. Material e método
- Trata-se de estudo exploratório com análise documental descritiva das 433 guias
de referenciamento de pacientes atendidos no ambulatório de Cardiologia Pediátrica
da Policlínica Municipal de Sorocaba, no período de janeiro a junho de 2012,
acompanhado do estudo dos prontuários. Os dados obtidos foram quantificados e
utilizada a estatística descritiva quando pertinente. Resultados - Cento e sessenta e
seis pacientes (38,3%) tiveram alta, 93 com contrarreferência (56,0%) preenchida.
Noventa e seis pacientes (22,2%) perderam o seguimento, sendo nove com doença
cardiovascular presente, 29 com doença cardiovascular ausente e 58 sem
diagnóstico definitivo de doença cardiovascular. Cento e setenta e um pacientes
(39,5%) pacientes mantêm seguimento. Conclusão A fim de se fortalecer a rede
de atenção à saúde, a utilização de recentes avanços, como a telemedicina e o
conceito de apoio matricial se colocam como meios de troca, otimização e
racionalização do conhecimento e dos recursos
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Devenir neuropsychologique et psychosocial d’adultes ayant été opérés d’une cardiopathie congénitale cyanogène en période néonatale / Neuropsychological and psychosocial outcomes in adults after neonatal surgery for cyanotic congenital heart diseaseKasmi, Leila 10 November 2016 (has links)
Les cardiopathies congénitales cyanogènes (CCC) sont des malformations cardiaques qui entraînent une désaturation en oxygène à la naissance. Des progrès majeurs réalisés ces vingt dernières années dans la prise en charge médico-chirurgicale des nouveau-nés atteints de CCC ont permis de considérablement améliorer la survie et le pronostic cardiaque à long terme de cette population. Cependant, ces enfants sont exposés à un risque accru d’accidents neurologiques dû au caractère cyanogène de la cardiopathie et à certaines techniques de chirurgie à cœur ouvert. En conséquence, les troubles neurocognitifs font partie des principales morbidités résiduelles. Malgré l’augmentation exponentielle du nombre de patients qui atteignent dorénavant l’âge adulte, à ce jour très peu d’études ont investigué le devenir neuropsychologique des adultes opérés de CCC. Cette thèse a pour objectif principal d’évaluer le devenir neuropsychologique et psychosocial d’adultes ayant été opérés à cœur ouvert en période néonatale pour corriger une CCC. L’évaluation, qui repose sur des outils validés, est menée auprès de 67 patients âgés de 18 à 31 ans. Les résultats mettent en évidence qu’une proportion substantielle de patients présente des troubles cognitifs et émotionnels susceptibles de réduire leur qualité de vie et d’entraver leur réussite scolaire et leur insertion professionnelle. Ce travail offre des résultats pionniers concernant le devenir à long terme de cette population. D'autres études sont nécessaires pour mieux comprendre la trajectoire développementale des adultes opérés de CCC afin de mettre en place des stratégies préventives et thérapeutiques adaptées aux besoins de cette population. / Cyanotic congenital heart diseases (CHD) are heart defects which cause oxygen desaturation at birth. In the last twenty years, the major progress in the medical and surgical care of newborns with cyanotic CHD has resulted in a considerable improvement of the survival and the long-term cardiac prognosis of this population. However, these children are at an increased risk of neurological injuries due not only to the cyanotic nature of their CHD but also to certain open-heart surgery techniques. Consequently, neurocognitive disorders are among the major remaining morbidities in this population. Despite the exponential increase in the number of patients who can now reach adulthood, to date very few studies have investigated the neuropsychological outcomes of adults with cyanotic CHD. The main objective of the present thesis is to evaluate the neuropsychological and psychosocial outcomes of adults who had undergone an open-heart surgery during the neonatal period in order to correct a cyanotic CHD. The assessment, based on validated tools, is conducted among 67 patients aged from 18 to 31 years. The results show that a substantial proportion of patients with TGA presents a number of cognitive deficits and emotional impairments which may reduce their quality of life and hinder their academic success and their professional integration. This thesis offers original results on the long-term neuropsychological and psychosocial outcomes of this population. Further studies are needed so as to better understand the developmental trajectory of adults with cyanotic CHD in order to develop preventive and therapeutic strategies adapted to the specific needs of this population.
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Qualité de vie en cardiologie pédiatrique et congénitale / Quality of life in pediatric and congenital cardiologyAmedro, Pascal 12 May 2016 (has links)
Les cardiopathies congénitales (CC) représentent la première cause d’anomalie malformative à la naissance. Les progrès considérables des années 80 (CEC néonatale, diagnostic prénatal) en ont modifié l’épidémiologie, avec un transfert de la mortalité de la pédiatrie à l’âge adulte. Dans ce contexte, l’évaluation de la qualité de vie liée à la santé (QdV) des enfants et adultes porteurs de CC devient un critère de jugement important, en recherche clinique comme dans les soins. Nous avons mené 4 études prospectives de QdV chez des patients avec CC: une étude chez 282 enfants de 8 à 18 ans avec CC comparés à 180 enfants contrôles; une étude sur 202 enfants avec CC corrélant QdV et VO2; une étude de QdV sur 208 adolescents et adultes porteurs d'HTAP sur CC; et une étude sur l’évolution de la QdV de 111 enfants sous AVK participant à un programme d’éducation thérapeutique. Les patients avec CC simple ont manifesté une QdV similaire à celle de la population générale. Ceux avec une cardiopathie complexe ont été préférentiellement impactés sur leur bien-être physique mais ont développé aussi des mécanismes de coping. En pédiatrie, l’évaluation de la QdV par les parents était plus péjorative mais parfois plus pertinente que celle des enfants. Nous avons mis en évidence le lien entre QdV et VO2 chez l’enfant cardiaque. Les résultats de nos travaux devraient permettre d’aider les cardiologues, cardiopédiatres et chirurgiens cardiaques dans leurs annonces diagnostiques, en particulier lors des moments cruciaux de notre sur-spécialité médico-chirurgicale: diagnostic prénatal, réanimation, transition vers l’âge adulte, prise en charge palliative d’une cardiopathie sévère. / Congenital heart diseases (CHD) are the leading cause of birth malformations. The tremendous progress since the 80’s (neonatal bypass, prenatal diagnosis) have changed the epidemiology, transferring mortality from pediatrics to adulthood. Therefore assessing the health-related quality of life (QoL) of children and adults suffering from CHD has become an important issue, in both clinical research and patients’ follow-up. We carried out 4 prospective QoL studies in patients with CHD: a study in 282 CHD children aged 8 to 18 compared with 180 controls; a study among 202 CHD children correlating their QoL scores to VO2; a QoL study among 208 adolescents and adults with PAH-CHD; and a study among 111 children in a therapeutic anticoagulation education program aiming to measure the evolution of their QoL. Patients with simple CHD showed a similar QoL to that of the control population. Those with complex heart diseases were preferentially affected in their physical well-being but also developed mechanisms of coping in other dimensions. In pediatrics, the evaluation of the QoL by parents is essential, sometimes more accurate than that of children themselves. As in previous studies in adults with heart failure, we found a significant relationship between QoL and physical performance during exercise in CHD children. The results of our work should help cardiologists, cardiac surgeons and pediatric cardiologists in their diagnostic announcement, especially during crucial moments of this medical and surgical subspecialty: prenatal diagnosis, intensive care, transition of care from adolescence to adulthood, palliative treatment of a complex CHD.
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Etude du rôle des gènes HOX dans le développement du cœur chez la souris / Study of the role of Hox genes during heart development in the mouseRoux, Marine 16 December 2013 (has links)
Les gènes Hox sont essentiels à la mise en place de l’identité des cellules le long de l’axe antéropostérieur des embryons et pourraient agir en aval de l’acide rétinoïque pendant la formation du cœur. Nous montrons que les gènes Hoxb1, Hoxa1 et Hoxa3 définissent des sous-domaines du second champ cardiaque. L’analyse de lignage génétique révèle que les progéniteurs cardiaques Hoxb1+ contribuent aux oreillettes et à la partie inférieure de la voie efférente, futur myocarde sous-pulmonaire. Les progéniteurs Hoxa1+ contribuent à la partie distale de la voie efférente, suggérant un rôle de ces gènes Hox antérieurs dans sa régionalisation proximo-distale. Alors qu’aucune anomalie cardiaque n’avait été décrite chez les mutants Hoxb1, notre étude détaillée des fœtus Hoxb1-/- révèle des défauts d’alignement des gros vaisseaux ainsi que des communications interventriculaires. L’utilisation d’un marqueur du myocarde sous-pulmonaire, montre une contribution anormale des cellules du second champ cardiaque à cette région chez les mutants. Nous montrons que ces défauts sont la conséquence de la dérégulation des voies de signalisation présentes dans le second champ cardiaque. En accord avec ces observations, les embryons ont une voie efférente plus courte. L’étude des mutants Hoxa1 révèle des malformations des arcs pharyngés puis des anomalies de la crosse aortique chez les fœtus. L’analyse des doubles mutants, montre une augmentation de la pénétrance et de la sévérité de ces défauts, suggérant une interaction synergique entre Hoxa1 et Hoxb1 lors de la formation des gros vaisseaux. Ces résultats révèlent un rôle crucial des gènes Hox antérieurs dans le développement du cœur. / Hox genes are known to be involved in the establishment of cell position and identity along the anterior-posterior axis in embryos and could act as key downstream effectors of retinoic acid during heart development. In situ hybridization experiments show that Hoxb1, Hoxa1 and Hoxa3 define sub-domains within the second heart field (SHF). Our genetic lineage analysis reveals the contribution of Hoxb1+ cardiac progenitors to the atria and to the inferior wall of the outflow tract (OFT), which then gives rise to the myocardium at the base of the pulmonary trunk. Interestingly, Hoxa1+ progenitors contribute to the distal part of the OFT suggesting that these anterior Hox genes could play a role in its proximo-distal patterning. No cardiac anomalies had been reported so far in Hoxb1 mutant mice. However, our detailed study shows that mutant fetuses exhibit OFT misalignment and ventricular septal defects associated or not with ventricular wall and epicardium anomalies. Using a marker of the sub-pulmonary myocardium, we observe an abnormal contribution of SHF cells in Hoxb1-/- hearts. This defect is the consequence of the dysregulation of the signaling pathways controlling SHF regulation. Accordingly, those embryos exhibit a shorter OFT. The study of Hoxa1 mutant embryos reveals pharyngeal arch arteries patterning defects causing anomalies of the aortic arch and right subclavian artery at fetal stages. Using compound mutants, we show an increase in the penetrance and severity of these defects, suggesting a synergistic interaction between Hoxa1 and Hoxb1 during aortic arch patterning. Together, these data support a crucial role for anterior Hox genes in cardiac development.
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Vliv dávkování genu Nkx2.5 na vývoj a elektrofyziologii srdce u myši / Role of Nkx2.5 on development and electrophysiology of the mouse heartHámor, Peter January 2015 (has links)
Role of Nkx2.5 on development and electrophysiology of the mouse heart Prague 2015 Bc. Peter Hámor ABSTRACT The objective of this thesis is to investigate the role of Nkx2.5 gene dosage on electrophysiology of the mouse heart in prenatal stage of its development, in which the physiological functions of the heart fail to function properly. The main goal of this work is to search for differences in conduction of electric impulses through the embryonic mouse heart according to their genotype. Special method of capturing the conduction of electric impulse through myocardium was used for this purpose, called optical mapping. Thanks to this method I was able to construct images and videos capturing transition of the impulse with marked beginning of the activation and its direction in the heart. These outputs, or optical maps, help to define anomalies and defects compared with a normal functioning heart. The thesis focuses on the expression of the transcription factor Nkx2.5 and regulatory components related with the correct formation and physiology of the heart until 9.5 days post coitum. Individuals in this developmental stage were optically mapped and compared according to their genotypes - homozygous non-mutant, heterozygote and homozygous mutant mouse embryos exhibited some degree of similarity, while other...
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Μοντελοποίηση της ροής του αίματος σε στένωση προκαλούμενη από περίδεση της πνευμονικής αρτηρίας / Blood flow modeling in the stenosis induced by the pulmonary artery bandingΜπάκα, Πανωρέα 07 July 2010 (has links)
Οι καρδιαγγειακές παθήσεις αποτελούν την κύρια αιτία θανάτου στις αναπτυγμένες χώρες. Η στένωση σε μία αρτηρία, είτε αυτή προκαλείται από μία πάθηση όπως το ανεύρυσμα, είτε προκαλείται από μία περίδεση, όπως στις περιπτώσεις των συγγενών καρδιοπαθειών, μπορεί να μεταβάλλει σε σημαντικό βαθμό τα χαρακτηριστικά της ροής του αίματος. Η μελέτη της φυσιολογικής παλλόμενης ροής μέσα από στένωση είναι ιδιαίτερα σημαντική για τη διάγνωση και αντιμετώπιση των αγγειακών νόσων.
Το ιατρικό πρόβλημα το οποίο εξετάζουμε στην παρούσα εργασία, είναι η στένωση της πνευμονικής αρτηρίας από περίδεση. Η περίδεση γίνεται προφανώς για να μειωθεί η υψηλή αρτηριακή πίεση και τελικά η ροή του αίματος προς τους πνεύμονες. Πρόκειται για μία χειρουργική μέθοδο αντιμετώπισης συγγενών καρδιοπαθειών.
Η περίδεση της πνευμονικής αρτηρίας (pulmonary artery banding - PAB) είτε με συμβατικό τρόπο, ή με την πλέον σύγχρονη μέθοδο μέσω της συσκευής FloWatchTM προκαλεί τη στένωσή της. Με τον συμβατικό τρόπο η στένωση μπορεί να θεωρηθεί αξονικά συμμετρική, ωστόσο με τη χρήση του FloWatchTM είναι μη αξονικά συμμετρική. Έχει αποδειχθεί ότι τόσο η αξονικά συμμετρική, όσο και η μη συμμετρική περίδεση δημιουργεί διαφόρου βαθμού ίνωση του τοιχώματος της πνευμονικής αρτηρίας. Η αναδόμηση της πνευμονικής αρτηρίας είναι πολύ ηπιότερη στην περίπτωση της περίδεσης με το FloWatchTM. Η διαφοροποίηση αυτή έγκειται κυρίως στο ότι η συμβατική περίδεση προκαλεί για συγκεκριμένη μείωση της διατομής ισχυρότερη μείωση της περιμέτρου της διατομής από εκείνης της περίδεσης με το FloWatchTM.
Στην παρούσα εργασία γίνεται αναφορά και ανάλυση των διαφόρων περιπτώσεων ροής σε στενώσεις αρτηριών, των συγγενών καρδιοπαθειών και των τεχνικών περίδεσης της πνευμονικής αρτηρίας. Επιπρόσθετα, μελετήθηκαν και υπολογίστηκαν η μόνιμη και η παλλόμενη ροή σε αξονικά συμμετρική 25% στένωση προκαλούμενη από συμβατική περίδεση, καθώς και η μόνιμη και παλλόμενη ροή σε μη συμμετρική 25% στένωση της πνευμονικής αρτηρίας όπως προκαλείται από το FloWatchTM, μέσω των πακέτων Fluent και Gambit.
Η υπολογιστική μελέτη του πεδίου ροής περιλαμβάνει την κατανομή ταχυτήτων, τον προσδιορισμό των περιοχών ανακυκλοφορίας, την κατανομή των πιέσεων και την σύγκριση των παραπάνω μεγεθών με τα αντίστοιχα αποτελέσματα της βιβλιογραφίας. Τέλος, με βάση τα αποτελέσματα γίνεται η σύγκριση των δύο μελετούμενων μεθόδων περίδεσης.
Αριθμητικά ρεαλιστικά δεδομένα ελήφθησαν από την καρδιοχειρουργική κλινική του νοσοκομείου Παίδων «Αγία Σοφία». / Cardiovascular diseases are the leading cause of death in developed countries. A stenosis in an artery , caused either by a disease such as an aneurism or by a banding (such as in congenital diseases) can change the characteristics of the blood flow very seriously. The study of the physiological pulsatile flow through a stenosis is very important for the diagnosis and treatment of the arterial diseases.
The medical problem which is examined in this study is pulmonary artery stenosis caused by a banding. The banding takes place to reduce the high arterial pressure and finally the blood flow from the heart to the lungs. It is a surgical method used for treatment of congenital heart diseases.
The pulmonary artery banding either with the use of the conventional method or the most modern with the use of the FloWatchTM technology causes stenosis of the artery. With the conventional method, stenosis can be considered axially symmetrical while with the use of FloWatchTM it is asymmetrical. It has been proven that both the axially symmetrical and asymmetrical banding cause fibrosis of the pulmonary artery walls of different degrees. The reconstruction of the pulmonary artery is milder where there is banding with FloWatchTM. This differentiation is based mainly on the fact that the conventional banding causes, for a specific decrease of the cross-section, a decrease in the perimeter of the cross-section higher than that of banding with FloWatchTM.
In this assignment there is a report of different cases of flow in arterial stenosis, in congenital heart diseases and pulmonary banding techniques. In addition what was studied and appreciated was the steady and pulsatile flow in axially symmetrical 25% stenosis caused by the conventional banding, as well as the steady and pulsatile flow in asymmetrical 25% stenosis of pulmonary artery caused by FloWatchTM with the use of Fluent and Gambit.
The numerical study of flow distribution includes velocity distribution, designation of back flow area, distribution of pressure and comparison of these quantities with the results in bibliography. Finally, based on the results, there is a comparison of the two banding methods under study.
The numerical realistic data were received from the cardio-surgical clinic of children’s hospital “Aghia Sophia”.
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