OBJETIVO: Analisar as freqüências de malformações congênitas detectadas ao nascimento no Rio Grande do Sul, enfocando especialmente aquelas passíveis de Diagnóstico Pré-Natal através do Estudo Morfológico Fetal, para sugerir, ao final, uma rotina mínima de exame ultra-sonográfico fetal. MÉTODOS: Inicialmente realizou-se um estudo descritivo de base populacional dos bancos de dados oficiais do Rio Grande do Sul referentes aos defeitos congênitos no estado. Foi delimitado o período de 2001 a 2005, sendo incluídos todos recém-nascidos vivos que foram registrados ao nascimento como portadores de uma ou mais anomalias congênitas na Declaração de Nascidos Vivos. Foram incluídos também os nascidos vivos falecidos com menos de um ano, com causa mortis atribuída a um defeito congênito e os óbitos fetais cuja Declaração de Óbito registrou defeitos congênitos. Para fins deste estudo, foram analisados 25 defeitos ou grupos de defeitos, levando em conta suas prevalências relatadas na literatura, gravidade, possibilidade de diagnóstico pré-natal ou no exame do recém-nascido. A seguir foram estudadas as possibilidades de Diagnóstico Pré-Natal dos principais defeitos congênitos através da ultra-sonografia, tendo como base na literatura atual e buscando-se elaborar uma rotina mínima de exame fetal. RESULTADOS: Os 25 defeitos ou grupos de defeitos representaram 81,74% do total dos 6.236 recém nascidos com defeitos identificados no nascimento. No período de 2001-2005 nasceram no estado 765.230 bebês, com média anual de 153.046. A ocorrência geral de defeitos diagnosticados no nascimento no período foi de 0,81%, sendo relatadas as freqüências específicas daqueles 25 defeitos. Identificou-se que 787 casos de defeitos congênitos que faleceram no 1º ano de vida não foram diagnosticados ao nascimento. Calculou-se que para cada caso de cardiopatia diagnosticado no nascimento cerca de 3 casos não foram percebidos e faleceram no 1º ano de vida. Estes cálculos foram expressivos também para trissomias do 13 e 18 (3:1) e sistema nervoso central (1,28:1). CONCLUSÕES: A análise das freqüências de defeitos congênitos no Rio Grande do Sul mostrou que 25 defeitos ou grupo de defeitos representam mais de 80% do total das ocorrências no estado. Alguns defeitos congênitos registrados ao nascimento no Campo 34 da Declaração de Nascidos Vivos parecem estar subestimados, especialmente aqueles cujo diagnóstico necessita de exames especializados, como as cardiopatias congênitas. Este estudo sugere que com a avaliação ultra-sonográfica de 18 planos da anatomia fetal se pode rastrear a maioria dos defeitos congênitos do nosso meio. / OBJECTIVE: To analyze the frequency of congenital defects detected at birth in Rio Grande do Sul, focusing mainly on those that can be diagnosed prenatally by a Fetal Morphological Ultrasound Study, and finally, to suggest a minimum routine for fetal ultrasonographic examination. METHODS: Initially a population-based descriptive study was performed of the Rio Grande do Sul (RS) state official database referring to congenital defects in the state. The period from 2001 to 2005 was delimited, and all livebirths recorded in the Declaration of Livebirths as having one or more congenital anomalies were included. Babies born alive who died at less that one year of age were also included if their cause of death was attributed to a congenital defect, and the fetal deaths when the Death Declaration recorded congenital defects. For the purposes of this study, 25 defects or groups of defects were analyzed, taking into account their prevalence reported in the literature, severity, possibility of prenatal diagnosis or diagnosis during the examination of the newborn. Next the possibilities of Prenatal Diagnosis of the main congenital defects by ultrasound were studied based on the current literature and trying to create a minimum routine for a fetal examination. RESULTS: The 25 defects or groups of defects were 81.74% of the total of 6,236 newborns with defects identified at birth. During the 2001-2005 period, 765,230 babies were born in the state, with an annual mean of 153,046. The overall occurrence of defects diagnosed at birth during the period was 0.81%, and the specific frequencies of those 25 defects were reported. It was found that 787 cases with congenital defects that died in the first year of life were not diagnosed at birth. It was calculated that for each case of cardiopathy diagnosed at birth, about 3 cases were not perceived, and died during the 1st year of life. These calculations were also important for trisomies 13 and 18 (3:1) and the central nervous system (1.28:1). CONCLUSIONS: The analysis of frequencies of congenital defects or groups of defects that represents more than 80% of them. Some congenital defects recorded in the Declaration of Livebirths at field number 34 seams to be underestimates, like the congenital cardiopathies. This study suggest that with the ultrasonographic evaluation of 18 planes of fetal anatomy the majority of congenital defects can be traced.

OBJETIVO: Analisar as freqüências de malformações congênitas detectadas ao nascimento no Rio Grande do Sul, enfocando especialmente aquelas passíveis de Diagnóstico Pré-Natal através do Estudo Morfológico Fetal, para sugerir, ao final, uma rotina mínima de exame ultra-sonográfico fetal. MÉTODOS: Inicialmente realizou-se um estudo descritivo de base populacional dos bancos de dados oficiais do Rio Grande do Sul referentes aos defeitos congênitos no estado. Foi delimitado o período de 2001 a 2005, sendo incluídos todos recém-nascidos vivos que foram registrados ao nascimento como portadores de uma ou mais anomalias congênitas na Declaração de Nascidos Vivos. Foram incluídos também os nascidos vivos falecidos com menos de um ano, com causa mortis atribuída a um defeito congênito e os óbitos fetais cuja Declaração de Óbito registrou defeitos congênitos. Para fins deste estudo, foram analisados 25 defeitos ou grupos de defeitos, levando em conta suas prevalências relatadas na literatura, gravidade, possibilidade de diagnóstico pré-natal ou no exame do recém-nascido. A seguir foram estudadas as possibilidades de Diagnóstico Pré-Natal dos principais defeitos congênitos através da ultra-sonografia, tendo como base na literatura atual e buscando-se elaborar uma rotina mínima de exame fetal. RESULTADOS: Os 25 defeitos ou grupos de defeitos representaram 81,74% do total dos 6.236 recém nascidos com defeitos identificados no nascimento. No período de 2001-2005 nasceram no estado 765.230 bebês, com média anual de 153.046. A ocorrência geral de defeitos diagnosticados no nascimento no período foi de 0,81%, sendo relatadas as freqüências específicas daqueles 25 defeitos. Identificou-se que 787 casos de defeitos congênitos que faleceram no 1º ano de vida não foram diagnosticados ao nascimento. Calculou-se que para cada caso de cardiopatia diagnosticado no nascimento cerca de 3 casos não foram percebidos e faleceram no 1º ano de vida. Estes cálculos foram expressivos também para trissomias do 13 e 18 (3:1) e sistema nervoso central (1,28:1). CONCLUSÕES: A análise das freqüências de defeitos congênitos no Rio Grande do Sul mostrou que 25 defeitos ou grupo de defeitos representam mais de 80% do total das ocorrências no estado. Alguns defeitos congênitos registrados ao nascimento no Campo 34 da Declaração de Nascidos Vivos parecem estar subestimados, especialmente aqueles cujo diagnóstico necessita de exames especializados, como as cardiopatias congênitas. Este estudo sugere que com a avaliação ultra-sonográfica de 18 planos da anatomia fetal se pode rastrear a maioria dos defeitos congênitos do nosso meio. / OBJECTIVE: To analyze the frequency of congenital defects detected at birth in Rio Grande do Sul, focusing mainly on those that can be diagnosed prenatally by a Fetal Morphological Ultrasound Study, and finally, to suggest a minimum routine for fetal ultrasonographic examination. METHODS: Initially a population-based descriptive study was performed of the Rio Grande do Sul (RS) state official database referring to congenital defects in the state. The period from 2001 to 2005 was delimited, and all livebirths recorded in the Declaration of Livebirths as having one or more congenital anomalies were included. Babies born alive who died at less that one year of age were also included if their cause of death was attributed to a congenital defect, and the fetal deaths when the Death Declaration recorded congenital defects. For the purposes of this study, 25 defects or groups of defects were analyzed, taking into account their prevalence reported in the literature, severity, possibility of prenatal diagnosis or diagnosis during the examination of the newborn. Next the possibilities of Prenatal Diagnosis of the main congenital defects by ultrasound were studied based on the current literature and trying to create a minimum routine for a fetal examination. RESULTS: The 25 defects or groups of defects were 81.74% of the total of 6,236 newborns with defects identified at birth. During the 2001-2005 period, 765,230 babies were born in the state, with an annual mean of 153,046. The overall occurrence of defects diagnosed at birth during the period was 0.81%, and the specific frequencies of those 25 defects were reported. It was found that 787 cases with congenital defects that died in the first year of life were not diagnosed at birth. It was calculated that for each case of cardiopathy diagnosed at birth, about 3 cases were not perceived, and died during the 1st year of life. These calculations were also important for trisomies 13 and 18 (3:1) and the central nervous system (1.28:1). CONCLUSIONS: The analysis of frequencies of congenital defects or groups of defects that represents more than 80% of them. Some congenital defects recorded in the Declaration of Livebirths at field number 34 seams to be underestimates, like the congenital cardiopathies. This study suggest that with the ultrasonographic evaluation of 18 planes of fetal anatomy the majority of congenital defects can be traced.

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.

Dans cette thèse nous traitons de la simulation numérique des écoulements sanguins dans le contexte des maladies cardiaques congénitales. Nous nous concentrons d'une part sur l'intégration de données cliniques, et d'autre part sur les aspects de couplages multi-échelles. Dans l'introduction, nous présentons les pathologies structurelles du cœur et les traitements chirurgicaux nécessaires dans certaines cardiopathies sévères. Puis, nous consacrons un chapitre aux challenges liés à la simulation numérique des écoulements sanguins. Dans les deux chapitres suivants nous présentons une méthodologie permettant d'estimer des paramètres de modèles réduits modélisant l'arbre artériel pulmonaire, en y intégrant des mesures cliniques prises pour chaque patient à différents endroits avant intervention chirurgicale. Cette méthode est appliquée sur neuf patients et permet de représenter l'hémodynamique dans les artères pulmonaires pour chacun des patients. Le chapitre suivant est consacré au couplage des équations de Navier-Stokes 3D avec un modèle réduit, qui soulève des problèmes d'instabilités numériques dans nombre d'applications. Nous présentons d'abord un état de l'art des couplages 3D-0D communément utilisés pour ce type de problème. Nous présentons de plus une étude de stabilité pour montrer quels sont les avantages et inconvénients de chacun d'eux. Ensuite, nous présentons une nouvelle méthode de couplage 3D-3D qui est similaire, d'un point de vue énergétique, au couplage avec un modèle réduit. Nous comparons enfin les méthodes existantes à ce couplage 3D-3D sur trois cas de patients, côtés systémique et pulmonaire. Dans le dernier chapitre de cette thèse, nous nous intéressons à la propagation des incertitudes des données cliniques sur la simulation de l’hémodynamique dansle cadre de chirurgie virtuelle. / In this thesis, we deal with numerical simulation of blood flow in the context of congenital heart diseases. We focus on clinical data integration into reduced models, and from a numerical point view on the coupling of blood flow (3D Navier-Stokes equations) and reduced models. In the introduction, we present congenital heart diseases and the surgical palliations needed for severe pathologies. We then present a chapter on challenges in numerical simulations of blood flow. In the next chapters, we present a methodology to estimate parameters of reduced models taking into account the effect of the pulmonary vasculature and the clinical measurements performed at different locations prior to surgical intervention of each patient. This method is applied to nine patient-specific cases and provides a representation of the hemodynamics in pulmonary arteries at different palliation stages. The next part of this thesis is devoted to numerical coupling between 3D blood flow and reduced models, which leads to numerical instability in a number of applications. We first present the state of the art for the different coupling methods, and perform a stability analysis of each coupling approach, highlighting the pros and cons. Moreover we present the new 3D-3D coupling method which presents the same energy balance as the 3D-reduced model. We compare all these methods on three systemic or pulmonary patient-specific cases to assess the robustness and accuracy of each one. In the last part of this manuscript we present a framework to investigate the effect of uncertainty of clinical measurements on our methodology to estimate reduced models for surgery planning: we focus on the impact of clinical data uncertainty to estimate blood flow distribution and pressure loss due to a stenosis to assess if it should be removed or not.

L’objectif général de cette thèse est d’explorer le développement des fonctions exécutives (FE) et des théories de l’esprit (TdE) chez l’enfant ayant une cardiopathie congénitale cyanogène (CCC) et ceci à une période clé dans la construction de ces capacités de « haut niveau » et dans leurs relations fonctionnelles réciproques. L’étude des enfants ayant une CCC et présentant un risque d’hypoxie circonscrit à la période néonatale permet d’explorer la vulnérabilité précoce des capacités neurocognitives à maturation tardive comme les FE et les TdE. En adoptant une approche longitudinale et transversale, nos objectifs visent à (1) déterminer la trajectoire développementale des FE (inhibition, mémoire de travail et flexibilité cognitive) et spécifier la nature et le degré de leurs dysfonctionnements (2) caractériser le développement des capacités méta-représentationnelles et évaluer le rôle prédictif des différentes composantes exécutives dans les TdE de premier et deuxième ordre, (3) explorer la généralisation des dysfonctionnements aux TdE avec un contenu mental affectif, (4) déterminer les facteurs de risque neurologique néonataux associés aux déficits exécutifs et en TdE, (5) évaluer la contribution des dysfonctionnements exécutifs, des variables médicales et démographiques sur la prévalence de prise en charge de ces enfants. Une cohorte de 45 enfants nés avec une CCC opérés à coeur ouvert en période néonatale et un groupe d’enfants sains ont été évalués à un âge moyen de 5 ans (T1) puis ont été à nouveau testés pendant deux années consécutives (T2 et T3). Nos résultats ont mis en évidence un profil de dysfonctionnement hétérogène selon l’âge et le domaine cognitif. Ainsi, naitre avec une CCC altère la progression développementale des FE et des TdE avec toutefois une normalisation pour les composantes ayant une émergence plus précoce. Les liens prédictifs observés entre les niveaux initiaux des FE et le développement ultérieur des TdE reflètent des mécanismes de construction typiques mais néanmoins décalés dans le temps. Enfin, le diagnostic prénatal de la CCC, qui a un rôle neuroprotecteur face au risque de cyanose néonatale, est également associé à un meilleur pronostic des FE et des TdE. Ce travail de thèse offre des résultats pionniers dans la compréhension de l’impact des vulnérabilités neurologiques néonatales sur la dynamique développementale de fonctions neurocognitives complexes. / The general aim of this doctoral dissertation is to explore the development of executive functions (EF) and theory of mind (ToM) in school-aged children with a cyanotic congenital heart disease (CHD) at a key developmental period of progression and functional interactions between these “higher order functions”. The study of children born with a cyanotic CHD and exposed to a hypoxic risk limited to the neonatal period allows to explore the early vulnerability of late developing neurocognitive functions such as EF and ToM. We used a longitudinal and cross-sectional approach in order to: (1) determine the developmental trajectory of EF (inhibition, working memory and cognitive flexibility) and specify their nature and degree of impairment, (2) characterize the development of meta-representational abilities as well as EFs predictive roles in first- and second-order ToM, (3) evaluate the potential generalization of dysfunction to ToM with an affective component, (4) determine neonatal neurological risk factors associated to EF and ToM impairments, (5) evaluate the impact of executive impairments and medical and demographic variables on the early use of remediation services in these children. A cohort of 45 children born with a cyanotic CHD who underwent neonatal open-heart surgery and a group of comparison children were evaluated at a mean age of 5 years (T1) and then followed-up for two consecutive years (T2 and T3). Our results showed a heterogeneous pattern of dysfunction depending on age and specific domains. Cyanotic CHD affects the dynamics of development for these functions even though the earliest developing abilities tend to normalize. Predictive relations observed between early EF and later ToM suggest typical developmental mechanisms though chronologically delayed. Finally, prenatal diagnosis of the cyanotic CHD, known to play a neuroprotective role for cyanosis management is also associated to a better prognosis for EF and ToM outcomes. This work offers pioneer results on the comprehension of the impact of neonatal neurological vulnerabilities on the developmental dynamics of complex neurocognitive abilities.

A partir de données en population, nous avons: 1) évalué le risque de cardiopathies congénitales (CC) chez les fœtus conçus par assistance médicale à la procréation (AMP); et 2) déterminé les effets de l’AMP sur la prise en charge prénatale et le devenir périnatal des fœtus porteurs de CC. Nous avons observé que l'AMP était associée à une augmentation de 40% du risque de CC sans anomalies chromosomiques associées (OR ajusté = 1,4 IC95% 1,1-1,7). Nous avons également retrouvé qu'il existait des associations variables selon la catégorie de CC et la méthode d'AMP considérées. Nous avons observé que l'AMP était associée à une multiplication par 2,4 du risque de tétralogie de Fallot (OR ajusté = 2,4 IC95% 1,5-3,7), alors que nous n’avons pas retrouvé d’association statistiquement significative pour les trois autres CC spécifiques étudiées. Dans notre population, l'exposition à l'AMP ne semblait pas modifier le recours au diagnostic prénatal et à l'interruption médicale de grossesse chez les fœtus porteurs de CC comparés aux fœtus porteurs de CC conçus spontanément. Nous avons par ailleurs observé que le risque de prématurité des fœtus porteurs de CC conçus par AMP était environ 5 fois plus élevé que celui des fœtus porteurs de CC conçus spontanément (OR ajusté = 5,0 IC95% 2,9-8,6). En nous basant sur une méthodologie d'analyses de cheminement, nous avons retrouvé que les grossesses multiples contribuaient pour environ 20% au risque plus élevé de tétralogie de Fallot associé à l'AMP que nous avons observé. Enfin, les grossesses multiples contribuaient pour environ 2/3 du risque de prématurité associé à l'AMP chez les fœtus porteurs de CC. / Using population-Based data, we: 1) assessed the risk of congenital heart defects (CHD) in assisted reproductive techniques (ART) conceived fetuses; and 2) evaluated the effects of ART on prenatal management and perinatal outcomes of fetuses with CHD. We observed that ART were associated with a 40% increased risk of CHD without associated chromosomal anomalies (adjusted OR = 1.4 95%CI 1.1-1.7). We also found varying associations between the different methods of ART and categories of CHD. We observed that ART were associated with 2.4-Higher odds of tetralogy of Fallot (adjusted OR = 2.4 95%CI 1.5-3.7), whereas no statistically significant association was found for the three other specific CHD included. In our population, ART exposure did not seem to modify prenatal diagnosis and termination of pregnancy for fetal anomaly in fetuses with CHD compared to fetuses with CHD conceived spontaneously. The risk for premature birth in fetuses with CHD conceived following ART was 5-Fold higher as compared to fetuses with CHD conceived spontaneously (adjusted OR = 5.0 95%CI 2.9-8.6). Using a path-Analysis method, we found that multiple pregnancies contributed for about 20% to the higher risk of tetralogy of Fallot associated with ART that we had found. Finally, multiple pregnancies contributed for the 2/3 of the risk of premature birth associated with ART in fetuses with CHD.

Le nombre d'adultes porteurs de cardiopathies congénitales, de plus en plus sévères est constante progression. A moyen voire long terme certain d’entre eux posent des problèmes d’insuffisance cardiaque et de troubles du rythme parfois létaux. La physiologie de ces complications est multi factorielle et s’écarte souvent des schémas habituels. L’asynchronisme ventriculaire présentent chez un nombre important d’entre eux est connu pour favoriser un remodelage ventriculaire conduisant à l’insuffisance cardiaque sur cœur sain.Dans ce travail en couplant données expérimentales animales et études cliniques, nous avons étudié : 1) l’impact aigu puis chronique de la resynchronisation biventriculaire sur un modèle animal d’insuffisance cardiaque droite mimant la tétralogie de Fallot et sur une population de patients ; 2) le rôle et la conséquence d’une stimulation conventionnelle sur une physiologie de ventricule droit systémique ; 3) l’effet délétère de la stimulation VD prolongée sur un modèle de cœur animal en cours de développement.Nous avons appris que 1) la resynchronisation biventriculaire permet un bénéfice hémodynamique significatif chez l’animal mais aussi sur une population de Fallot implantées ; 2) que l’asynchronisme généré par la stimulation conventionnelle est délétère pour la fonction du ventricule systémique mais aussi pour le cœur de l’enfant en cours développement. La resynchronisation est un traitement prometteur pour traiter l’insuffisance cardiaque mais pourrait aussi l’être pour en prévenir sa survenue. De nouvelles techniques d’implantation nous permettent aujourd’hui d’implanter des patients qui présentent beaucoup d’obstacles anatomiques et d’éviter nombre de complications grave de la stimulation. / The number of adults with severe congenital heart disease is constantly growing. At medium to long-term follow up, these patients may present with heart failure or conduction disorders, which may lead to death. The pathophysiology and clinical course of these complications is multi-factorial and may be different from that in patients without congenital heart disease. In normal hearts, electromechanical dyssynchrony is known to induce ventricular remodeling and heart failure. Ventricular asynchrony is also present in a substantial number of adults with congenital heart disease. In this study, we combined animal experiments and clinical studies to investigate: 1) the acute and chronic effect of biventricular resynchronization therapy on cardiac function in an animal model mimicking right ventricular heart failure in Tetralogy of Fallot, as well as in patients with Tetralogy of Fallot; 2) the consequences of conventional ventricular pacing in patients with ‘systemic right ventricle physiology’; 3) the effects of chronic right ventricular pacing in an animal model of the developing heart.We found that: 1) biventricular resynchronization induces significant hemodynamic benefit in the animal model of Tetralogy of Fallot as well as in Fallot patients; 2) ventricular asynchrony induced by conventional ventricular pacing is deleterious to the function of the systemic right ventricle; 3) chronic right ventricular pacing is harmful to the developing (pediatric) heart with normal biventricular anatomy. Cardiac resynchronization therapy is promising as a treatment for heart failure, but may also prevent heart failure. Nowadays, new implantation techniques allow us to implant pacing devices in patients with limited anatomical access due to prior surgery and help to avoid numerous severe complications of conventional pacing therapy