Dissertations / Theses on the topic 'Ablation par cathéter de radiofréquence'
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Da, Costa Antoine. "Le flutter auriculaire : évolution du traitement par radiofréquence." Saint-Etienne, 2003. http://www.theses.fr/2003STET014T.
Hoyland, Philip. "Computer-assisted electrophysiological intervention treating complex ventricular arrhythmias." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0271.
Since the beginning of the nineties and the use of radiofrequency to ablate cardiac arrhythmias, electrophysiologists treat rhythm disorders of increasing complexity. 3D mapping systems enable catheter locations to be determined with high precision and therefore are very important tools for cardiac electrophysiologists. Identifying zones of interest remains long and involves a great number of steps based on indirect analyses of the heart's electrical properties. The main objective of the thesis is the development of new tools to locate the critical isthmus in patients who have ventricular tachycardia after myocardial infarction. The clear identification of the circuit components of the ventricular tachycardia enables the implementation of an ablation strategy to treat the patient. The studied methods do not require a 12-lead electrocardiogram (ECG) of the ventricular tachycardia and therefore have the advantage of being able to be used even if the ventricular tachycardia cannot be initiated during the procedure. Pace mapping consists of stimulating the myocardium and analyzing the induced signal, the 12-lead morphology and the S-QRS interval. A major area of research is the development of an algorithm that automatically extracts the relevant data obtained during pace mapping. This facilitates the display of multi-parametric maps highlighting potential reentry circuits. Another area of research is the development of a graph-based method to study the variations of the electrical properties of the ventricle. The paced points are considered as vertices of a graph. Each edge is given a weight and finding the path between two vertices of minimum weight allows the analysis of potential reentry circuits
Navoret, Nicolas. "Analyse et détection des électrogrammes complexes fractionnés en vue de soigner la fibrillation auriculaire à l'aide de techniques d'ablation par radiofréquence." Phd thesis, Université de Bourgogne, 2013. http://tel.archives-ouvertes.fr/tel-00926703.
Elbes, Delphine. "Thermothérapies par ultrasons focalisés et radiofréquences guidées par imagerie de résonance magnétique." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14683/document.
My manuscript studies the development of mini and non invasive thermotherapies guided by magnetic resonance imaging (MRI) in the treatment of hepatic and cardiac diseases. The first part was the development of a method to increase the lesion size, induced by HIFU, and based on bubble enhanced heating (BEH). The acoustic power threshold of the BEH was determined by MR acoustic radiation force imaging (MR-ARFI) and the thermal effect was characterized by MR thermometry on ex vivo and in vivo in pig livers. The second part developed a strategy to perform HIFU through the rib cage using beam steering to track the respiratory movement or to performed multipoint ablation while avoiding heating of ribs. Transducer elements localized in the geometric projection of the shadow of ribs, relatively to the targeted focal point, were switched off.The third part was the development of the MR thermometry on the heart for the monitoring of radiofrequency ablation (RFA). Several aspects were investigated, in particular the thermometry precision, the feasibility to perform catheter radiofrequency ablation under MR thermometry in vivo in a sheep heart, the possibility to use the catheter as an MR antenna to increase spatial resolution of MR thermometry images
Pasquié, Jean-Luc. "Ablation du flutter auriculaire par courant de radiofréquence." Montpellier 1, 1995. http://www.theses.fr/1995MON11055.
Gauffre, Olivier. "Ablation par cathéter endocavitaire des fibres de mahain : à propos de 6 cas." Bordeaux 2, 1992. http://www.theses.fr/1992BOR23073.
Toupin, Solenn. "Cardiac MR thermometry for the monitoring of radiofrequency ablation." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0346/document.
Radiofrequency ablation is a therapeutic procedure for the treatment of cardiac arrhythmia by inducing a local necrosis of the arrhythmogenic tissue. This intervention is currently performed without online imaging of the lesion formation during radiofrequency delivery. MR thermometry provides a monitoring of temperature in the targeted tissue in each pixel and an immediate estimation of lesion via the calculation of the thermal dose. If this technique is well established for the guidance of tumor ablation in various organs, it remains challenging in the heart due to motion (breathing and myocardial contraction). In this work, a cardiac MR thermometry method was developed to perform a real-time temperature mapping of the heart under free-breathing conditions. Several MR pulse sequences were designed to ensure the acquisition of up to 5 slices per heartbeat with a voxel size of 1.6X1.6X3 mm3. Different solutions of minimization of out-of-plane motion were evaluated: alignment of the slices in the main direction of displacement, dynamic update of slice position depending on the respiratory state (echo-navigator, measure of the catheter position). Residual in-plane motion and associated susceptibility artifacts were corrected by real-time algorithms to allow a precision of MR thermometry of ±2°C in ventricles. This protocol was successfully used for the monitoring of radiofrequency ablation in sheep (N=3), allowing a correlation (R=87) between thermal dose maps and sizes of created lesions. These results are promising regarding the relevance of this measure for an inline estimation of the lesion extent during ablation
Ficai, Silvia. "Traitement par ablation par radiofréquence et stimulaion simple chambre des cardiopathies obstructives en fibrillation auriculaire chronique." Montpellier 1, 1999. http://www.theses.fr/1999MON11097.
Brusson, Matthieu. "CAThéter Hyperfréquence pour ARythmies : CATHAR : détermination de la profondeur de brulure de tissus biologiques par voie microonde." Thesis, Dijon, 2015. http://www.theses.fr/2015DIJOS016/document.
Cardiac arrhythmia substrates may be treated by intracardiac ablations which consist in burning specific atrial or ventricular endocardial substrates. Created lesions which are not transmural may be responsible for arrhythmia recurrences. To date, the depth of the lesion inside the endocardium can't be assessed accurately during the procedures. Our experimental work has focused on microwave characterization of biological tissues (in vitro) to assess the burn depth. Using a reflection technique with a coaxial probe in contact with tissues, measurements were made over a wide frequency range (100 MHz to 6 GHz). The measured reflection coefficient is known to be directly related to the dielectric properties of the tissues. We therefore measured the relative variation of the reflection of the tissue. In order to determine the burn depth of the tissue, the imaginary part of the relative variation is studied as a function of the real part of the relative variation for each frequency. Thus, we observe an evolution of the signal as a function of the burn depth. The determination of the tissue burned depth in a liquid medium is possible
Meo, Marianna. "Caractérisation spatio-temporelle de l’électrocardiogramme de surface pour prédire le résultat de l’ablation par cathéter de la fibrillation atriale persistante." Thesis, Nice, 2013. http://www.theses.fr/2013NICE4122/document.
Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice, and one of the main causes of stroke. Yet its thorough characterization and treatment remain an open issue. Despite the increasing popularity of the radiofrequency catheter ablation (CA) therapy, very little is known about its impact on heart substrate, leading to rather uncertain success rates. This calls for advanced signal processing tools for quantitatively assessing CA outcome. The surface 12-lead electrocardiogram (ECG), a noninvasive and cost-effective cardiac activity recording modality, provides valuable information about AF. However, some issues affect most of the standard CA outcome predictors, e.g., manual computation and limited single-lead perspective. This thesis aims at explicitly exploiting the ECG’s multilead character through multivariate decomposition tools, so as to enhance the role of some ECG features as CA outcome predictors. Fibrillatory wave amplitude is correlated with CA success in a multilead framework through principal component analysis (PCA). Multivariate approaches also enhance AF spatiotemporal variability measured on the ECG (e.g., weighted PCA, nonnegative matrix factorization), evidencing that the less repetitive the AF pattern, the less likely CA success. Information theory also quantifies interlead similarity between AF patterns, and is linked with CA outcome in a multilead framework. Another perspective focuses on the ventricular response as reflected on heart rate variability (HRV). Point process modeling can highlight certain HRV properties typical of AF in a parametric probabilistic context, helping AF pattern recognition
Seror, Oliver. "Adaptation et évaluation du monitorage par IRM de température des ablations hépatiques par radiofréquence." Bordeaux 2, 2006. http://www.theses.fr/2006BOR21331.
In this work the feasibility and the accuracy of MR-thermometry based on the proton resonance frequency shift and using the concept of thermal dose for the monitoring of radiofrequency ablation in the liver were assed. Before the achievement of a clinical pilot study, we carried out three experimental studies : the first was performed ex vivo on liver samples, the second in vivo in the liver of rabbits and the third in vivo in the liver of pigs using clinical available radiofrequency material. Finally the clinical study consisted of the treatment of malignant liver tumours of eight patients by radiofrequency ablation under continuous MR-thermometry monitoring. At each steps of this work Mr-thermometry appeared as a faeasible and reliable monitoring technique to assess in real time the extent of ablation zone during radiofrequency ablation. Further changes in imaging protocol and in the radiofrequency material might improve significantly the effectiveness of this new monitoring imaging
Robert, Frédéric. "Ablation de la conduction auriculo-ventriculaire par radiofréquence pour le traitement de l'arythmie supra-ventriculaire : résultats et devenir." Bordeaux 2, 1995. http://www.theses.fr/1995BOR23097.
Souteyrand, Philippe. "Ablation radioguidée des masses rénales." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM5072/document.
The therapeutic management of renal tumors has changed considerably in recent years with the advent of minimally invasive therapies (such as percutaneous radiofrequency) that maximize nephron savings, improves patient comfort with efficiency comparable to surgical oncology treatments reference. The next step would be to propose transcutaneous treatment (HIFU, stereotactic radiotherapy ...) as efficient with optimized morbidity and mortality.The objective of this work in the context of the LIIE of CERIMED (Aix-Marseille Université) and CRCHUM (Université de Montréal) was to develop an alternative to percutaneous renal radiofrequency we use in clinical practice Marseille for over 10 years and has proved its worth. This alternative must be capable of treating renal masses with a level of effectiveness and complication rates at least equal to the RFA, by applying transcutaneous physical agents without percutaneous approach (project KITT (Kidney Tracking Tumor)). This requires the design of technical point detection in real time of the renal tumor.We were able to develop a reliable identification algorithm that has yet to be optimized (speed of calculation) and be validated on a model that is not yet available. Work optimization and validation of segmentation algorithms, cross correlation merit function associated with Simplex optimization function, are underway as part of an international collaboration to French-Canadian LIIE and LIO.Even if we have not the opportunity to offer this type of treatment, our work allows to approach in order to offer them in the coming years
Prudhomme, Michel. "Traitement des tumeurs hépatiques par thermothérapie interstitielle induite par le laser diode." Montpellier 1, 2000. http://www.theses.fr/2000MON1T020.
Sacher, Frédéric. "Caractéristiques et traitements des cicatrices myocardiques responsables d'arythmie ventriculaire." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0032/document.
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
Cabrera, Lozoya Rocío. "Planification de l’ablation radiofréquence des arythmies cardiaques en combinant modélisation et apprentissage automatique." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4059/document.
Cardiac arrhythmias are heart rhythm disruptions which can lead to sudden cardiac death. They require a deeper understanding for appropriate treatment planning. In this thesis, we integrate personalized structural and functional data into a 3D tetrahedral mesh of the biventricular myocardium. Next, the Mitchell-Schaeffer (MS) simplified biophysical model is used to study the spatial heterogeneity of electrophysiological (EP) tissue properties and their role in arrhythmogenesis. Radiofrequency ablation (RFA) with the elimination of local abnormal ventricular activities (LAVA) has recently arisen as a potentially curative treatment for ventricular tachycardia but the EP studies required to locate LAVA are lengthy and invasive. LAVA are commonly found within the heterogeneous scar, which can be imaged non-invasively with 3D delayed enhanced magnetic resonance imaging (DE-MRI). We evaluate the use of advanced image features in a random forest machine learning framework to identify areas of LAVA-inducing tissue. Furthermore, we detail the dataset’s inherent error sources and their formal integration in the training process. Finally, we construct MRI-based structural patient-specific heart models and couple them with the MS model. We model a recording catheter using a dipole approach and generate distinct normal and LAVA-like electrograms at locations where they have been found in clinics. This enriches our predictions of the locations of LAVA-inducing tissue obtained through image-based learning. Confidence maps can be generated and analyzed prior to RFA to guide the intervention. These contributions have led to promising results and proofs of concepts
Meo, Marianna. "Caractérisation spatio-temporelle de l'électrocardiogramme de surface pour prédire le résultat de l'ablation par cathéter de la fibrillation atriale persistante." Phd thesis, Université Nice Sophia Antipolis, 2013. http://tel.archives-ouvertes.fr/tel-00940440.
Gillet, Tristan. "Echocardiographie trans-œsophagienne et angiographie sélective concernant l'étude des veines pulmonaires avant l'ablation par radiofréquence de la fibrillation auriculaire paroxystique." Bordeaux 2, 2000. http://www.theses.fr/2000BOR23098.
Ghrissi, Amina. "Ablation par catheter de fibrillation atriale persistante guidée par dispersion spatiotemporelle d’électrogrammes : Identification automatique basée sur l’apprentissage statistique." Thesis, Université Côte d'Azur, 2021. http://www.theses.fr/2021COAZ4026.
Catheter ablation is increasingly used to treat atrial fibrillation (AF), the most common sustained cardiac arrhythmia encountered in clinical practice. A recent patient-tailored AF ablation therapy, giving 95% of procedural success rate, is based on the use of a multipolar mapping catheter called PentaRay. It targets areas of spatiotemporal dispersion (STD) in the atria as potential AF drivers. STD stands for a delay of the cardiac activation observed in intracardiac electrograms (EGMs) across contiguous leads.In practice, interventional cardiologists localize STD sites visually using the PentaRay multipolar mapping catheter. This thesis aims to automatically characterize and identify ablation sites in STD-based ablation of persistent AF using machine learning (ML) including deep learning (DL) techniques. In the first part, EGM recordings are classified into STD vs. non-STD groups. However, highly imbalanced dataset ratio hampers the classification performance. We tackle this issue by using adapted data augmentation techniques that help achieve good classification. The overall performance is high with values of accuracy and AUC around 90%. First, two approaches are benchmarked, feature engineering and automatic feature extraction from a time series, called maximal voltage absolute values at any of the bipoles (VAVp). Statistical features are extracted and fed to ML classifiers but no important dissimilarity is obtained between STD and non-STD categories. Results show that the supervised classification of raw VAVp time series itself into the same categories is promising with values of accuracy, AUC, sensi-tivity and specificity around 90%. Second, the classification of raw multichannel EGM recordings is performed. Shallow convolutional arithmetic circuits are investigated for their promising theoretical interest but experimental results on synthetic data are unsuccessful. Then, we move forward to more conventional supervised ML tools. We design a selection of data representations adapted to different ML and DL models, and benchmark their performance in terms of classification and computational cost. Transfer learning is also assessed. The best performance is achieved with a convolutional neural network (CNN) model for classifying raw EGM matrices. The average performance over cross-validation reaches 94% of accuracy and AUC added to an F1-score of 60%. In the second part, EGM recordings acquired during mapping are labeled ablated vs. non-ablated according to their proximity to the ablation sites then classified into the same categories. STD labels, previously defined by interventional cardiologists at the ablation procedure, are also aggregated as a prior probability in the classification task.Classification results on the test set show that a shallow CNN gives the best performance with an F1-score of 76%. Aggregating STD label does not help improve the model’s performance. Overall, this work is among the first attempts at the application of statistical analysis and ML tools to automatically identify successful ablation areas in STD-based ablation. By providing interventional cardiologists with a real-time objective measure of STD, the proposed solution offers the potential to improve the efficiency and effectiveness of this fully patient-tailored catheter ablation approach for treating persistent AF
Kwiatkowski, Yves. "Fulguration endocavitaire du faisceau de his dans le traitement des troubles du rythme supraventriculaire rebelles : à propos de vingt patients." Lille 2, 1988. http://www.theses.fr/1988LIL2M250.
Champ-Rigot, Laure. "Nouvelles perspectives diagnostiques et thérapeutiques dans la prise en charge rythmologique des patients en situation d'insuffisance cardiaque Rationale and Design for a Monocentric Prospective Study: Sleep Apnea Diagnosis Using a Novel Pacemaker Algorithm and Link With Aldosterone Plasma Level in Patients Presenting With Diastolic Dysfunction (SAPAAD Study) Usefulness of sleep apnea monitoring by pacemaker sensor in elderly patients with diastolic dysfunction : the SAPAAD Study Clinical outcomes after primary prevention defibrillator implantation are better predicted when the left ventricular ejection fraction is assessed by magnetic resonance imaging Predictors of clinical outcomes after cardiac resynchronization therapy in patients ≥75 years of age: a retrospective cohort study Comparison between novel and standard high-density 3D electro-anatomical mapping systems for ablation of atrial tachycardia Safety and acute results of ultra-high density mapping to guide catheter ablation of atrial arrhythmias in heart failure patients Long-term clinical outcomes after catheter ablation of atrial arrhythmias guided by ultra-high density mapping system in heart failure patients." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMC430.
Heart failure is a major public health issue in developed countries, with a prevalence of 1-2% of global population, rising to 10% after 70 years of age. Therapeutic progresses have succeeded in improving patients’ prognosis, particularly in case of reduced left ventricular ejection fraction. Rhythm abnormalities are frequent, and need special consideration in case of heart failure. Meanwhile, there are still some gaps in the evidence: heart failure with preserved systolic function is complex and difficult to treat, primary prevention of sudden cardiac death is effective but there is a need to better select candidates, whether elderly patients should be treated as younger individuals, and finally how to improve outcomes of atrial fibrillation catheter ablation. Firstly, we have conducted a prospective study to evaluate the Sleep Apnea Monitoring algorithm provided in a novel pacemaker in patients with diastolic dysfunction. Besides, we analyzed whether magnetic resonance imaging could predict cardiac outcomes in patients with an implantable cardioverter defibrillator better than echocardiography. We also reported the outcomes of the cardiac resynchronization therapy in patients ≥75 years old compared to younger patients. Finally, we studied the results of a novel ultra-high density mapping system to guide ablation procedures of complex atrial arrhythmias in heart failure patients compared to controls
Audigier, Chloé. "Modélisation de l’ablation radiofréquence pour la planification de la résection de tumeurs abdominales." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4071/document.
The outcome of radiofrequency ablation (RFA) of abdominal tumors is challenged by the presence of blood vessels and time-varying thermal conductivity, which make patient-specific planning extremely difficult. By providing predictive tools, biophysical models may help clinicians to plan and guide the procedure for an effective treatment. We introduce a detailed computational model of the biophysical mechanisms involved in RFA of hepatic tumors such as heat diffusion and cellular necrosis. It simulates the extent of ablated tissue based on medical images, from which patient-specific models of the liver, visible vessels and tumors are segmented. In this thesis, a new approach for solving these partial differential equations based on the Lattice Boltzmann Method is introduced. The model is first evaluated against clinical data of patients who underwent RFA of liver tumors. Then, a comprehensive pre-clinical experiment that combines multi-modal, pre- and post-operative anatomical and functional images, as well as the interventional monitoring of the temperature and delivered power is presented. This enables an end-to-end validation framework that considers the most comprehensive data set for model validation. Then, we automatically estimate patient-specific parameters to better predict the ablated tissue. This personalization strategy has been validated on 7 ablations from 3 clinical cases. From the pre-clinical study, we can go further in the personalization by comparing the simulated temperature and delivered power with the actual measurements during the procedure. These contributions have led to promising results, and open new perspectives in RFA guidance and planning
Jégou, Carole. "Intégration d'un film mince de Pb(Zr,Ti)O₃ dans une structure capacitive pour applications RF." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112322/document.
Ferroelectric materials are raising a lot of interest due to their physical properties such as piezoelectricity, ferroelectricity or high dielectric constant. Thus, they are generally integrated in micro- and nano-systems as thin films in a capacitive configuration. Especially, the lead zirconate titanate oxide (PZT) is an attractive material for capacitive RF applications due to its high dielectric constant. The growth of the PZT thin film has to be controlled on metallic electrodes for its integration on coplanar transmission lines. Moreover, electrical properties such as leakage current and ferroelectric behavior of PZT have to be monitored upon application of a dc voltage bias for RF device operation. In this context, PZT thin films were grown by the pulsed laser deposition technique (PLD) on a La₀.₆₇Sr₀.₃₃MnO₃ (LSMO) / Pt (111) electrode on a monocrystalline sapphire substrate. The LSMO buffer layer is mandatory to avoid the formation of the paraelectric pyrochlore phase. The control of the crystalline orientation of the LSMO layer allows for the control of the PZT layer texture. Leakage currents through the Pt/PZT/LSMO/Pt stack were then studied in the 220-330K temperature range to determine the conduction mechanisms. A transition is evidenced between a bulk-controlled mechanism near room temperature and an interface-controlled mechanism at low temperature. A hopping mechanism is identified above 280K in line with the presence of extended defects and the columnar structure of the PZT layer. Several strategies were tested to control leakage currents. The first one consists in inserting an insulating oxide layer at the top Pt/PZT interface. In this way, charge injection was modified and leakage currents were reduced. The second strategy consists in changing the PZT layer bulk structure by elaborating a layered or columnar dielectric/PZT composite. Thus, an insulating oxide layer was inserted in the middle of the PZT layer and permitted to reduce leakage currents. Moreover, the control of the PZT nucleation allowed for the elaboration of a columnar PZT/pyrochlore composite. The leakage currents in this composite can be tuned through the pyrochlore pillars density among the ferroelectric matrix. Then, PZT and the heterostructures for leakage current control were integrated in a capacitive RF structure with gold coplanar transmission lines. RF performances in terms of isolation and insertion loss of these materials were studied and gave good results. In particular the heterostructures developed to control the leakage currents are promising for their integration in capacitive RF devices. Besides, I tried to extract the permittivity of PZT at high frequency with the PZT layer in a capacitive configuration. This study highlighted the essential modifications of the capacitive structure that have to be made in order to be able to exploit PZT properties at high frequency
Saha, Mirabeau. "Modélisation de l’activité électrique des oreillettes avant et après ablation par cathéter." Thèse, 2015. http://hdl.handle.net/1866/13896.
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.
Billiard, Jean-Sébastien. "Impact d’un traitement pont par radiofréquence percutanée chez les patients porteurs d’hépatocarcinomes en attente de transplantation hépatique : modélisation de Markov et analyse de base de données locale." Thèse, 2018. http://hdl.handle.net/1866/22830.