Contexte ─ L’incidence, les caractéristiques, et le pronostic (vital et fonctionnel) de la mort subite du sportif n’ont pas été étudiés en population générale. Méthodes ─ Etude observationnelle prospective menée par l’Institut National de la Santé et de la Recherche Médicale en collaboration avec le Service d’Aide Médicale Urgente (SAMU) dans 60 départements français (2005–2010) incluant les sujets de 10 à 75 ans présentant une mort subite (récupérée ou non) au cours d’une activité sportive de loisir ou de compétition. La détection des cas a été assurée par deux sources indépendantes. L’information a été recueillie selon le modèle d’Utstein. Les incidences ont été calculées par million d’habitants et million de participants sportifs, en considérant les 20ème et 80ème percentiles des départements les plus participants. Des analyses complémentaires ont été menées chez les femmes et pour les sports les plus en cause. Compte tenu de disparités régionales importantes en termes de survie, la distribution des facteurs (individuels et communautaires) classiquement associés à la survie (à la sortie de l’hôpital) a été examinée dans 4 groupes de survie (<10%, 10–20, 20–40, et >40%). L’analyse des facteurs associés à la survie a été effectuée par régression logistique.Résultats ─ Au total, 820 cas ont été collectés, et l’incidence totale a été évaluée entre 5 et 17 cas par million d’habitants par an en France. Seulement 6% des cas sont survenus chez le jeune athlète de compétition. Après considération des taux de participation sportive, l’incidence chez l’homme a été estimée entre 11,2 (95% IC 10,4–12,1) et 33,8 (95% IC 30,9–36,8) cas par million de participants et par an, l’incidence chez la femme étant, en comparaison avec l’homme, extrêmement faible, en particulier chez les 40–54 ans avec un risque relatif de 0,03 (95% IC 0,01–0,07). L’incidence augmentait significativement avec l’âge chez l’homme (risque relatif 2,51, 95 % IC 2,10–3,01, quand âge >35 ans), et était plus importante dans certains sports (cyclisme vs. natation, p<0,0001). L’âge moyen des sujets était de 46±15 ans. Des antécédents cardiovasculaires étaient rapportés dans 12% des cas. Le taux de survie moyen à la sortie de l’hôpital était de 15,7% (95% IC 13,2–18,2), avec cependant des disparités départementales majeures (de 0 à 47%), alors que le pronostic neurologique restait favorable chez 80% des survivants. La description en 4 groupes de survie a démontré l’absence de différence significative en termes de caractéristiques des sujets, de circonstances de survenue, de délai de prise en charge, et de mortalité intra-hospitalière. A l’inverse, des différences majeures ont été observées concernant l’initiation du massage cardiaque par le témoin (15% à 81%, p<0,001), le rythme initialement choquable (29% à 79%, p<0,001), le niveau de formation de la population aux premiers secours (p<0,001) et la densité de défibrillateurs extra-hospitaliers dans le département (p<0,001). Le défibrillateur n’a que rarement été utilisé par les témoins avant l’arrivée des premiers secours (<1%). Au final, les facteurs individuels suivants étaient indépendamment associés à la survie à la sortie de l’hôpital : massage cardiaque par témoin (OR 3,73, 95% IC 2,19–6,39, p<0,0001), délai d’intervention (OR 1,32, 95% IC 1,08–1,61, p=0,006), présence d’un rythme choquable initial (OR 3,71, 95% IC 2,07–6,64, p<0,0001). Après ajustement sur les facteurs pronostiques individuels, seul le niveau de formation de la population aux premiers secours restait associé de façon significative à la survie (OR 1,64, 95% IC 1,17–2,31, p=0,004).Conclusions et perspectives ─ La mort subite est un problème de santé publique faisant intervenir les pompiers, le SAMU, les réanimateurs, les cardiologues, les épidémiologistes. Sa prise en charge est nécessairement multidisciplinaire et les progrès viendront d’une action concertée de santé publique. Concernant la mort subite du sportif, nos conclusions sont que (...) / Background – Although such data are available for young competitive athletes, the prevalence, characteristics and outcome of sports-related sudden cardiac death have not previously been assessed in the general population.Methods – A prospective and comprehensive national survey was carried out throughout France by the French Institute of Health and Medical Research from 2005 to 2010, involving subjects aged 10–75 years. Case detection for sports-related sudden cardiac death, during competitive or leisure activities, including resuscitated cardiac arrest, was undertaken via emergency medical services (Service d’Aide Médicale Urgente, SAMU) reporting and web-based screening of media releases. Data were collected according to Utstein’s style. Incidence calculations were reported by million of inhabitants as well as million of sports participants. Specific analyses were also carried out among women and specific sports. After having documented major regional survival disparities, we identified to which extent conventional evidence-based individual factors, known to be associated to survival, were distributed among different groups of survival. Moreover, we assessed if functional outcome was variable among groups of survival. Factors associated with survival were analyzed using regression logistic model.Results – The overall burden of sports-related sudden cardiac death was estimated between 5 and 17 cases per million inhabitants per year. Only 6% of cases occurred among young competitive athletes, with a specific incidence calculated to 9.8 (95% CI 3.7–16.0) per million per year. After considering participation rates, incidence in men sport participants was estimated from 11.2 (95% CI 10.4–12.1) to 33.8 (95% CI 30.9–36.8) per million of participants per year, dramatically higher than women-related incidence, particularly in the 45–54 year range (relative risk 0.03, 95% CI 0.01 to 0.07). By contrast with women, the incidence of sports-related sudden cardiac death in men significantly increased over age categories (p<0.0001), and incidence rates were substantially higher in men aged >35 years than men aged 35 years or less (RR 2.51, 95% CI 2.10–3.01). The mean survival rate at hospital discharge was 15.7% (95% CI 13.2–18.2), with major regional disparities among districts (from 0 to 47%), with however a highly similar favorable neurological outcome (80%). No difference was observed regarding subjects’ characteristics and circumstances of occurrence (including presence of witnesses, delays of intervention and public use of automatic external defibrillators) across survival groups. By contrast, major differences were noted regarding bystander initiation of cardiopulmonary resuscitation (15% to 81%, p<0.001) and presence of initial shockable rhythm (29% to 79%, p<0.001). Public use of automatic external defibrillator was dramatically low (<1%). Independent factors for survival included bystander cardiopulmonary resuscitation (OR 3.73, 95% CI 2.19–6.39, p<0.0001), initial shockable rhythm (OR 3.71, 95% CI 2.07–6.64, p<0.0001) and short delay between cardiac arrest and resuscitation (OR 1.32, 95% CI 1.08–1.61, p=0.006). After adjustment on individual factors, only population education to Basic Life Support was significantly associated with survival (OR 1.64, 95% CI 1.17–2.31, p=0.004).Conclusions and perspectives – Sudden cardiac death is a public health issue, with the need for a multidisciplinary approach involving Emergency Cares, Cardiology, and Epidemiology. Regarding sports-related sudden death, our conclusions are the following (...)

The first paper examines the value of a statistical life (VSL) for out-of-hospital cardiac arrest (OHCA) victims. We found VSL values to be higher for OHCA victims than for people who die in road traffic accidents and a lower-bound estimate of VSL for OHCA would be in the range of 20 to 30 million Swedish crowns (SEK). The second paper concerns hypothetical bias in contingent valuation (CV) studies. We investigate the link between the determinants and empirical treatment of uncertainty through certainty calibration and find that the higher the confidence of the respondents the more we can trust that stated WTP is correlated to actual WTP. The third paper investigates the performance of two communication aids (a flexible community analogy and an array of dots) in valuing mortality risk reductions for OHCA. The results do not support the prediction of expected utility theory, i.e. that WTP for a mortality risk reduction increases with the amount of risk reduction (weak scope sensitivity), for any of the communication aids. The fourth paper presents a cost-benefit analysis to evaluate the effects of dual dispatch defibrillation by ambulance and fire services in the County of Stockholm. The intervention had positive economic effects, yielding a benefit-cost ratio of 36, a cost per quality-adjusted life-year (QALY) of € 13 000 and the cost per saved life was € 60 000. The fifth paper explores how different response times from OHCA to defibrillation affect patients’ survival rates by using geographic information systems (GIS). The model predicted a baseline survival rate of 3.9% and reducing the ambulance response time by 1 minute increased survival to 4.6%. The sixth paper analyzes demographic determinants of incident experience and risk perception, and the relationship between the two, for eight different risk domains. Males and highly educated respondents perceive their risks lower than what is expected compared to actual incident experience.

No description available.

Sudden cardiac death following cardiac arrest is a major killer in the industrialised world. The leading cause of sudden cardiac death are disturbances in the normal electrical activation of cardiac tissue, known as cardiac arrhythmia, which severely compromise the ability of the heart to fulfill the body's demand of oxygen. Ventricular fibrillation (VF) is the most deadly form of cardiac arrhythmia. Furthermore, electrical defibrillation through the application of strong electric shocks to the heart is the only effective therapy against VF. Over the past decades, a large body of research has dealt with the study of the mechanisms underpinning the success or failure of defibrillation shocks. The main mechanism of shock failure involves shocks terminating VF but leaving the appropriate electrical substrate for new VF episodes to rapidly follow (i.e. shock-induced arrhythmogenesis). A large number of models have been developed for the in silico study of shock-induced arrhythmogenesis, ranging from single cell models to three-dimensional ventricular models of small mammalian species. However, no extrapolation of the results obtained in the aforementioned studies has been done in human models of ventricular electrophysiology. The main reason is the large computational requirements associated with the solution of the bidomain equations of cardiac electrophysiology over large anatomically-accurate geometrical models including representation of fibre orientation and transmembrane kinetics. In this Thesis we develop simulation technology for the study of cardiac defibrillation in the human heart in the framework of the open source simulation environment Chaste. The advances include the development of novel computational and numerical techniques for the solution of the bidomain equations in large-scale high performance computing resources. More specifically, we have considered the implementation of effective domain decomposition, the development of new numerical techniques for the reduction of communication in Chaste's finite element method (FEM) solver, and the development of mesh-independent preconditioners for the solution of the linear system arising from the FEM discretisation of the bidomain equations. The developments presented in this Thesis have brought Chaste to the level of performance and functionality required to perform bidomain simulations with large three-dimensional cardiac geometries made of tens of millions of nodes and including accurate representation of fibre orientation and membrane kinetics. This advances have enabled the in silico study of shock-induced arrhythmogenesis for the first time in the human heart, therefore bridging an important gap in the field of cardiac defibrillation research.

No description available.

The Thesis deals with the issue of provision of advanced life support in a Hospital. The main focus is the process, algorithm, of successive individual steps, its correct performance in practice should lead to the provision of effective CPR or to minimize subsequent post-resuscitation complications. The Thesis is mainly focused on non-medical health worker, as an important member of the healthcare team, his tasks, responsibilities and competences. The theoretical part will be processed according to the current guidelines of the European Resuscitation Council. Within the subsequent empirical part is included the methodology of realized research, the process of data collection, and the final interpretation of the results, followed by analysis and discussion. The survey is conducted by quantitative research, using the questionnaire survey. The aim of the research was to determine respondents' level of theoretical training, ways of continuing education and current conditions at selected workplaces. Based on detected results, the steps for nursing practice are proposed. KEY WORDS: advanced life support, sudden cardial arrest, sudden respiratory arrest, ventricular fibrillation, electrical defibrillation, algorithm of KPCR, post - resuscitation syndrome, activities of nurse.

L'arrêt cardiaque est principalement d'étiologie cardio-vasculaire. Dans le contexte actuel des arrêts cardiaques extrahospitaliers, 20 à 25% des victimes présentent une fibrillation ventriculaire. Environ 3 à 5% des personnes sont sauvées sans séquelle neurologique. La survie à un arrêt cardiaque extrahospitalier dépend d'une prise en charge précoce et rapide de la victime. Les premiers témoins actifs réalisant la réanimation cardio-pulmonaire combinée à l'utilisation d'un défibrillateur sont ainsi un maillon important pour sauver la victime.Notre objectif principal est d'améliorer le taux de survie à un arrêt cardiaque extrahospitalier. Une première voie d'investigation est de proposer un fonctionnement de défibrillateur optimal combinant judicieusement les différents modules de détection embarqués (détection de fibrillation ventriculaire, détection de massage cardiaque, détection d'interférences électromagnétiques) afin de réduire les temps de pause péri-choc durant la procédure de réanimation. En effet, pendant ces temps, dits « hands-off » en anglais, aucun geste de secours n'est administré au patient qui, lui, voit d'une part sa pression de perfusion coronarienne chuter, d'autre part la probabilité de succès des tentatives de défibrillation décroître. C'est pourquoi une deuxième voie d'investigation porte sur la prédiction de l'efficacité de choc. Dans ce contexte, nous proposons de combiner des paramètres de l'électrocardiogramme dans les domaines temporel, fréquentiel et de la dynamique non-linéaire. Un classifieur bayésien utilisant le modèle de mélange de gaussiennes a été appliqué aux vecteurs de paramètres les plus prédicteurs de l'issue de la défibrillation et l'algorithme Espérance-Maximisation a permis de mener à bien la procédure d'apprentissage des paramètres du modèle probabiliste représentant les distributions conditionnelles de classe.L'ensemble des méthodes proposées a permis d'atteindre des résultats prometteurs pour à la fois réduire les temps de pause péri-choc et prédire l'efficacité de défibrillation et ainsi espérer améliorer le taux de survie à un arrêt cardiaque / The cardiac arrest is mainly of cardiovascular etiology. In the actual context of out-of-hospital cardiac arrests, 20 to 25% of the victims present a ventricular fibrillation. About 3 to 5% of the victims are saved without neurological damage. The chance of surviving a cardiac arrest outside an hospital depends on the early and fast support of the victim. The first active witnesses performing cardiopulmonary resuscitation combined with the use of a defibrillator are an important link to save the victim.Our main objective is to improve survival rate in out-of-hospital cardiac arrest cases. A first way of investigation is to propose an optimal functioning of defibrillator combining wisely the different processes of detection embedded (ventricular fibrillation detection, chest compressions detection, electromagnetic interferences detection), in order to reduce the peri-shock pauses during the resuscitation procedure. In fact, during these pauses, known as "hands-off" pauses, no emergency action is provided to the patient, what is correlated to a drop of the coronary pression, but also to a decrease of the chance of successful defibrillation. That is the reason why, a second way of investigation is based on the prediction of the efficiency of defibrillation. In this context, we propose to use a combination of parameters extracted from electrocardiogram in time, frequency and non-linear dynamics domains. A bayesian classifier using a gaussian mixture model was applied to the vectors of parameters, which are the most predictor of the defibrillation outcome and the algorithm Expectation-Maximization allowed to learn the parameters of the probabilistic model representing the class conditional distributions.All of the proposed methods allowed to reach promising results for both reducing the peri-shock pauses and predicting the efficiency of defibrillation in hope to improve the survival rate in cardiac arrest cases