L’ablation par radiofréquence percutanée est un des traitements des tachycardiesventriculaires (TV). Bien que salvateur chez certains patients avec myocardiopathie (MCP),les taux de succès rapportés varient de 53 à 67% dans les centres entrainés.Le but de ce travail est d’essayer de mieux comprendre le substrat des arythmiesventriculaires et d’en améliorer le traitement. Pour cela, nous avons étudié le substrat despatients adressés pour ablation de TV (sur MCP ischémique, sur MCP dilatée à coronairessaines avec cicatrices sous épicardiques, chez les patients avec assistance ventriculairegauche et chez un patient avec syndrome de Brugada). Nous avons également évalué etproposé des outils/attitudes thérapeutiques pour essayer d’améliorer le traitement des TV.Nous avons mis en évidence des particularités électrophysiologiques pour chacun de cessubstrats qui permettent d’optimiser et d’adapter la cartographie et l’ablation chez cespatients. Par ailleurs, nous avons montré l’intérêt : (1) de nouvelles technologies pouraméliorer l’efficacité de l’ablation ; (2) des approches épicardiques ou d’alcoolisation intracoronaire, chez certains patients sélectionnés, qui permettent d’éliminer le substrat et (3)de l’imagerie cardiaque pour mieux identifier le substrat et diminuer les risques perprocédure.La connaissance du substrat spécifique à chaque pathologie, une information sur laforce du contact entre le cathéter et le tissu, l’imagerie cardiaque (scanner et IRM), uneapproche épicardique chez certains patients et l’homogénéisation de la cicatricemyocardique permettent d’être plus efficace lors de l’ablation des TV. / Radiofrequency (RF) catheter ablation is a recognized treatment for ventricular tachycardia(VT) in patients with structural heart disease. Even if it can be life saving, success rateremains around 53 to 67%.We aimed to better characterized VT substrate in patients with ischemic cardiomyopathy(CMP), non ischemic CMP with subepicardial scar, left ventricular assist device and Brugadasyndrome. We also evaluate the efficacy of new technologies (such as contact force), specificapproaches (epicardial access, intra coronary alcohol ablation), systematic use of cardiacimaging and new end-points for VT ablation.We demonstrated that each substrate had specific electrophysiological properties that helpoptimizing the mapping and the ablation in these patients. We also showed the interest of(1) new technologies to improve RF lesion formation; (2) specific approaches in selectedpatients to eradicate the VT substrate; and (3) cardiac imaging to help identifying thesubstrate and preventing complications. Finally using local abnormal ventricular potentialelimination as an end-point for VT ablation is feasible and associated with lower mortalityduring follow-up when achieved.Knowledge of substrate specificities, use of contact force, cardiac imaging, epicardial accessin selected patients and scar homogenization improve VT ablation efficacy and/or safety.

BACKGROUND: There are only limited data about peri-interventional pain during cardiac electrophysiological procedures without analgosedation. In this study, peri-interventional pain and recollection of it after the intervention were evaluated. METHODS: A total of 101 patients (43 electrophysiological/ablation procedures and 58 device surgeries) reported pain on a numerical rating scale (NRS; 0-10) before (pre), during (peri), and after (post) the intervention. Maximum pain (maxNRS) and the average of pain (meanNRS) were used for statistical analysis. Peri-interventional pain was compared with postinterventional data of the recollection of peri-interventional pain (peri-post). Patients were allocated into 2 groups (with 51 and 50 patients, respectively) to evaluate the mode of patient-staff interaction on pain recollection. Depressive, anxiety, and somatic symptom scales (Patient Health Questionnaire-15, Generalized Anxiety Disorder-7, and Patient Health Questionnaire-15) were used to analyze their influence on pain recollection. RESULTS: In total, 49.6% of patients (n = 50) complained of moderate to severe pain (maxNRS) at least once during the procedure. The comparison between peri and peri-post data revealed the following (median (range)-maxNRS, peri: 3 (0-10) versus peri-post: 4 (0-9) (ns), and meanNRS, peri: 1.4 (0-7) versus peri-post: 2.0 (0-6) (ns). The mode of patient-staff interaction had no influence on pain. No effect was found for psychosocial factor concerning pain and the recollection of pain. The results of the linear regression showed no influence of low-dose midazolam on recollection of pain. CONCLUSION: Half of the patients reported moderate to severe pain at least once during cardiac electrophysiological procedures without analgosedation. However, on average, patients reported only low pain levels. Postinterventional derived data on discomfort reflect the peri-interventional situation.:Inhaltsverzeichnis 1 Einführung in die Thematik 1.1 Hintergrund zur Thematik 1.2 Inhaltlicher Gegenstand 1.3 Fragestellung 2 Publikation 3 Zusammenfassung der Arbeit 4 Literatur I Darstellung des eigenen Beitrages II Selbstständigkeitserklärung III Lebenslauf IV Publikationen V Danksagung

No description available.

Atrial fibrillation is the most prevalent arrhythmia worldwide and remains one of the major causes of morbidity and mortality. Atrial fibrillation is an arrhythmia that has a various etiology and takes number of clinical forms. Due to the heterogenity of atrial fibrillation, it is necessary to individualize the optimal treatment strategy, ie conservative pharmacological therapy or interventional therapy as catheter ablation. Inncorrect indication of catheter ablation of atrial fibrillation leads to low success rate of the procedure and increases the risk of the procedure. The success rate of catheter ablation of atrial fibrillation depends on many clinical parameters, including the size and volume of the left atrium and the presence of pathological tissue in the atrial myocardium. In everyday practice, echocardiography (2D-echocardiography) is the most dominant method in estimation of the left atrial parameters, for it's simplicity, non- invasiveness, financial costs and the absence of ionizing radiation. Different methods for assesment of left atrial parameters are cardiac CT, cardiac magnetic resonance imaging and methods of 3-D echocardiography or 3-D angiography. The results of the present studies show that in patients with non-valvular atrial fibrillation who are indicated for catheter...

- Réalisé au centre de recherche de l'hospital du Sacré-Coeur de Montréal. - Programme conjoint entre Université de Montréal et École Polytechnique de Montréal. / La fibrillation auriculaire (FA) est la forme d’arythmie la plus fréquente chez les êtres humains. Les mécanismes qui gouvernent l’initiation et les manifestations de cette maladie sont complexes, de nature dynamique, incluant des interactions à travers multiples échelles temporelles et spatiales dans les oreillettes. Ceci conduit très souvent à des manifestations imprévisibles et à des phénomènes qui émergent à l’échelle de l’organe, et qui se reflètent à l’échelle de tout le torse. Pour remédier à ce problème, on peut effectuer une ablation par cathéter, qui consiste à créer sur le tissu auriculaire des lésions linéaires qui bloquent et contraignent la propagation électrique. Parfois, ces lignes se reconnectent quelque temps après l’intervention, ce qui mène à des récidives, nécessitant ainsi une nouvelle intervention. Le but de ce projet est de modéliser un suivi de l’onde P post-opératoire pour détecter de manière non-invasive la reconnexion des lignes d’ablation et ainsi prédire les récidives de fibrillation auriculaire. À l’aide d’un modèle mathématique des oreillettes et du thorax, les ondes P sont simulées avant et après ablation, ainsi qu’après reconnexion de certaines lignes d’ablation. Les résultats montrent que la morphologie et les caractéristiques de l’onde P, ainsi que la carte d’activation sont affectées significativement par l’ablation et les reconnexions subséquentes. Ces différences sont plus facilement détectables lorsque les reconnexions naissent sur la veine pulmonaire inférieure gauche. Les changements sont plus importants pour les électrodes placées sur certaines zones du torse, notamment dans le dos. Ces nouvelles données aident actuellement à la conception d’une étude clinique pour valider l’approche. / Atrial fibrillation (AF) is the most common form of arrhythmia in humans. The mechanisms governing the initiation and manifestations of that disease are complex, dynamic in nature, including interactions across multiple spatial and temporal scales in the atria. This often leads to unpredictable manifestations and phenomena that arise at the level of the organ, and are reflected across the entire torso. To remedy that problem, catheter ablation can be carried out, which consists in creating linear lesions which block and force the electrical propagation in the atrial tissue. Sometimes these lines reconnect after the procedure, which leads to atrial fibrillation recurrence, thus requiring a new intervention. The purpose of this work is to model the monitoring of the postoperative P wave to detect non-invasively the reconnection of ablation lines and to predict atrial fibrillation recurrences. Using a mathematical model of the atria and thorax, the P waves are simulated before and after ablation, as well as after reconnection of some ablation lines. The results show that the morphology and the characteristics of the P wave as well as the activation map are significantly affected by the ablation lines and the subsequent reconnections. These differences are more easily detected when reconnections arise on the left inferior pulmonary vein. The changes are most important in electrodes placed in certain areas of the torso, notably in the back. These new data are helping to plan a clinical study to validate the approach.

Fundamentos O acesso percutâneo ao espaço pericárdico pela via transatrial poderia ser uma alternativa ao acesso subxifóide para o mapeamento e ablação de fibras miocárdicas subepicárdicas. O objetivo deste estudo foi avaliar a viabilidade de alcançar o espaço pericárdico normal através do apêndice auricular direito (AAD) por acesso transvenoso. Métodos e Resultados - Um sistema Mullins (8F), originalmente desenvolvido para alcançar o átrio esquerdo (AE) por punção transeptal foi utilizado neste estudo para transfixar o AAD (16) ou AE (1) em 17 suínos, com uma média de 26,9 ± 2,6 kg, e alcançar o espaço pericárdico normal. Um cateter 7F quadripolar com eletrodo distal com 4 ou 8 mm foi introduzido no espaço pericárdico para aplicações de radiofrequência. Em 15 (88%) animais o procedimento foi realizado sem instabilidade hemodinâmica (PA média inicial = 80,4 ± 11.7 mmHg; PA média final = 86,8 ± 9.7 mmHg, p = 0,11). Foi identificado e aspirado derrame pericárdico discreto (28,9 ± 27.6 ml/animal) durante o procedimento. O espaço pericárdico foi acidentalmente acessado por punção do ventrículo direito (VD) em um animal e por punção do anel da valva tricúspide em outro. Ambos apresentaram sangramento xii pericárdico importante e tamponamento cardíaco. Um dispositivo para oclusão do orifício de perfuração foi testado com sucesso em três porcos, dois no AD e um no VD, sem ocorrência de derrame pericárdico significativo. Conclusões O acesso transatrial ao espaço pericárdico pode ser potencialmente útil para mapeamento e ablação de arritmias cardíacas, bem como para drenagem imediata de um tamponamento cardíaco agudo / Background A transvenous access to the pericardial space could provide a convenient route to map and ablate subepicardial myocardial fibers. The aim of this study was to evaluate the feasibility of reaching the normal pericardial space through the right atrial appendage (RAA) by transvenous access. Methods and Results An 8F Mullins system was used to transfix the right atrium (16) and left atrium (1) in 17 pigs with a mean of 26.9 ± 2.6 kg. A 7F quadripolar catheter with 4 or 8 mm distal tip electrode was introduced into the pericardial space to perform epicardial radiofrequency lesions. The pericardial space was successfully reached in 15 (88%) animals without hemodynamic instability (initial mean BP 80.4 ± 11.7 mmHg; final 86.8 ± 9.7 mmHg, p= 0,11). However, a mild pericardial serohemorrhagic effusion was identified and aspirated in all the animals (28.9 ± 27.6 ml/pig) during the procedure. The pericardial space was accidentally accessed through the right ventricle (RV) in one animal and through the tricuspid annulus in another, which presented important pericardial bleeding and cardiac tamponade. The hypothesis that an occlusion device could be useful to close the created atrial xiv orifice was tested successfully in thee pigs (two at RAA and one at RV) and without significant pericardial bleeding. Conclusions The right atrial appendage route might be potentially useful to access the normal pericardial space for mapping and ablating cardiac arrhythmias as well as to drain promptly an acute tamponade

No description available.

Fundamentos O acesso percutâneo ao espaço pericárdico pela via transatrial poderia ser uma alternativa ao acesso subxifóide para o mapeamento e ablação de fibras miocárdicas subepicárdicas. O objetivo deste estudo foi avaliar a viabilidade de alcançar o espaço pericárdico normal através do apêndice auricular direito (AAD) por acesso transvenoso. Métodos e Resultados - Um sistema Mullins (8F), originalmente desenvolvido para alcançar o átrio esquerdo (AE) por punção transeptal foi utilizado neste estudo para transfixar o AAD (16) ou AE (1) em 17 suínos, com uma média de 26,9 ± 2,6 kg, e alcançar o espaço pericárdico normal. Um cateter 7F quadripolar com eletrodo distal com 4 ou 8 mm foi introduzido no espaço pericárdico para aplicações de radiofrequência. Em 15 (88%) animais o procedimento foi realizado sem instabilidade hemodinâmica (PA média inicial = 80,4 ± 11.7 mmHg; PA média final = 86,8 ± 9.7 mmHg, p = 0,11). Foi identificado e aspirado derrame pericárdico discreto (28,9 ± 27.6 ml/animal) durante o procedimento. O espaço pericárdico foi acidentalmente acessado por punção do ventrículo direito (VD) em um animal e por punção do anel da valva tricúspide em outro. Ambos apresentaram sangramento xii pericárdico importante e tamponamento cardíaco. Um dispositivo para oclusão do orifício de perfuração foi testado com sucesso em três porcos, dois no AD e um no VD, sem ocorrência de derrame pericárdico significativo. Conclusões O acesso transatrial ao espaço pericárdico pode ser potencialmente útil para mapeamento e ablação de arritmias cardíacas, bem como para drenagem imediata de um tamponamento cardíaco agudo / Background A transvenous access to the pericardial space could provide a convenient route to map and ablate subepicardial myocardial fibers. The aim of this study was to evaluate the feasibility of reaching the normal pericardial space through the right atrial appendage (RAA) by transvenous access. Methods and Results An 8F Mullins system was used to transfix the right atrium (16) and left atrium (1) in 17 pigs with a mean of 26.9 ± 2.6 kg. A 7F quadripolar catheter with 4 or 8 mm distal tip electrode was introduced into the pericardial space to perform epicardial radiofrequency lesions. The pericardial space was successfully reached in 15 (88%) animals without hemodynamic instability (initial mean BP 80.4 ± 11.7 mmHg; final 86.8 ± 9.7 mmHg, p= 0,11). However, a mild pericardial serohemorrhagic effusion was identified and aspirated in all the animals (28.9 ± 27.6 ml/pig) during the procedure. The pericardial space was accidentally accessed through the right ventricle (RV) in one animal and through the tricuspid annulus in another, which presented important pericardial bleeding and cardiac tamponade. The hypothesis that an occlusion device could be useful to close the created atrial xiv orifice was tested successfully in thee pigs (two at RAA and one at RV) and without significant pericardial bleeding. Conclusions The right atrial appendage route might be potentially useful to access the normal pericardial space for mapping and ablating cardiac arrhythmias as well as to drain promptly an acute tamponade

BACKGROUND: Current guidelines give class I recommendations for uninterrupted use of dabigatran rivaroxaban as an alternative to vitamin K antagonist (VKA) in patients of atrial fibrillation (AF) who are undergoing catheter ablation. The recent randomized controlled trials have shown similar efficacy of novel oral anticoagulants when compared to VKA in these patients. We sought to perform a meta-analysis with a focus on subgroup analysis of novel oral anticoagulants. METHODS: We searched PubMed, Clinical trials registry and the Cochrane Center Register of Controlled Trials were searched through August 2020. Six RCTs studies (n = 2260) comparing the use of NOACs versus VKA in patients with AF undergoing catheter ablation were included. The odds ratio (OR) with 95% confidence interval was computed and P < 0.05 was considered as a level of significance. Major adverse cardiac events (MACE) were considered as a primary endpoint. RESULTS: Our results showed a significant difference in MACE between NOACs and VKA [OR 0.57 (0.37-0.88); P = 0.01] and in major bleeding events [OR 0.55 (0.35-0.86); P = 0.009], which is mainly derived from the use of dabigatran. No significant difference in MACE or major bleeding events was found on the subgroup analysis of rivaroxaban and apixaban over VKA therapy. CONCLUSION: Uninterrupted use of NOACs is safe and effective alternative for the prevention of cerebral thromboembolism and reducing the risk of major bleeding in patients undergoing catheter ablation of AF. However, the individual subgroup analysis showed that only dabigatran is superior to VKA in terms of reducing MACE through a reduction in major bleeding. The rivaroxaban, apixaban and edoxaban are non-inferior to VKA therapy based on these results. Further studies are needed to generalize these recommendations in morbidly obese patients.

A ablação cirúrgica por radiofreqüência (RF) é uma nova técnica para tratar a fibrilação atrial (FA) permanente. O objetivo deste estudo é avaliar a eficácia da ablação cirúrgica por RF da FA permanente em pacientes com valvopatia mitral reumática (VMR). Entre Fevereiro de 2002 e Abril de 2003, 70 pacientes com FA permanente e VMR foram submetidos à operação da valva mitral associada à ablação por RF da FA (Grupo A); ou à operação da valva mitral isolada (Grupo B). No seguimento pós-operatório foram avaliados: a reversão para o ritmo sinusal (RS) e a contratilidade atrial. Após 12 meses de seguimento, os índices de reversão para o RS e de restabelecimento da contratilidade atrial foram significativamente superiores no Grupo A. A ablação cirúrgica por RF é eficaz para o tratamento da FA permanente em pacientes com VMR / Radiofrequency ablation is a new surgical technique to treat permanent atrial fibrillation. The aim of this study was to evaluate the effectiveness of the (RF) ablation for the treatment of permanent AF in patients with rheumatic mitral valve (MV) disease. Between February 2002 and April 2003, 70 patients with permanent AF and rheumatic MV disease were assigned to undergo a MV surgery associated with RF ablation (Group A), or MV surgery alone (Group B). After 12 months of follow-up, the cumulative rates of sinus rhythm conversion and atrial transport function restoration were higher in Group A.The RF ablation is effective for treating permanent AF associated with rheumatic MV disease