Multi-scale Entropy Evaluates the Proarrhythmic Condition of Persistent Atrial Fibrillation Patients Predicting Early Failure of Electrical Cardioversion

[EN] Atrial fibrillation (AF) is nowadays the most common cardiac arrhythmia, being associated with an increase in cardiovascular mortality and morbidity. When AF lasts for more than seven days, it is classified as persistent AF and external interventions are required for its termination. A well-established alternative for that purpose is electrical cardioversion (ECV). While ECV is able to initially restore sinus rhythm (SR) in more than 90% of patients, rates of AF recurrence as high as 20-30% have been found after only a few weeks of follow-up. Hence, new methods for evaluating the proarrhythmic condition of a patient before the intervention can serve as efficient predictors about the high risk of early failure of ECV, thus facilitating optimal management of AF patients. Among the wide variety of predictors that have been proposed to date, those based on estimating organization of the fibrillatory (f-) waves from the surface electrocardiogram (ECG) have reported very promising results. However, the existing methods are based on traditional entropy measures, which only assess a single time scale and often are unable to fully characterize the dynamics generated by highly complex systems, such as the heart during AF. The present work then explores whether a multi-scale entropy (MSE) analysis of thef-waves may provide early prediction of AF recurrence after ECV. In addition to the common MSE, two improved versions have also been analyzed, composite MSE (CMSE) and refined MSE (RMSE). When analyzing 70 patients under ECV, of which 31 maintained SR and 39 relapsed to AF after a four week follow-up, the three methods provided similar performance. However, RMSE reported a slightly better discriminant ability of 86%, thus improving the other multi-scale-based outcomes by 3-9% and other previously proposed predictors of ECV by 15-30%. This outcome suggests that investigation of dynamics at large time scales yields novel insights about the underlying complex processes generatingf-waves, which could provide individual proarrhythmic condition estimation, thus improving preoperative predictions of ECV early failure.This research has been supported by grants DPI2007-83952-C3 from MINECO/AEI/FEDER EU, SBPLY/17/180501000411 from Junta de Comunidades de Castilla la Mancha and AICO/2019/036 from Generalitat Valenciana.Cirugeda Roldan, EM.; Calero, S.; Hidalgo, VM.; Enero, J.; Rieta, JJ.; Alcaraz, R. (2020). Multi-scale Entropy Evaluates the Proarrhythmic Condition of Persistent Atrial Fibrillation Patients Predicting Early Failure of Electrical Cardioversion. 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Evaluating MDC with incentives in P2PTV systems

The popularity of P2P video streaming is raising the interest of broadcasters, operators and service providers. Concretely, mesh-pull based P2P systems are the most extended ones. Despite these systems address scalability efficiently, they still present limitations that difficult them to offer the same user experience in comparison with traditional TV. These ones are mainly the freeriding effect, long start-up delays and the impact of churn and bandwidth heterogeneity. In this paper we study the performance of Multiple Description Coding (MDC) combined with the use of incentives for redistribution in order to mitigate some of them by means of simulations. Simulation results show that the use of MDC and incentive-based scheduling strategies improve the overall performance of the system. Moreover, an extended version of the P2PTVSim simulator has been developed to support MDC and incentives.Peer ReviewedPostprint (published version

Comparative study of the pharmacologic potency of four preparations of Carbamacepin

El objeto del presente estudio fue evaluar la potencia anticonvulsivante de tres formulaciones farmacéuticas de Carbamacepina y de la materia prima sin procesamiento, en ratones, frente al Pentilenetetrazol (PTZ), una sustancia química convulsivante. Para ello se determinó el porcentaje de inhibición del efecto letal de PTZ con 4 dosis de cada formulación y de la materia prima. En este modelo experimental, los resultados señalan que no hay diferencias significativas en la capacidad de antagonizar el efecto de la dosis máxima de PTZ entre las 4 preparaciones bajo estudio. Por lo tanto, se sugiere que no diferirían en su efecto anticonvulsivante.The aim of the present study was to assess the anticonvulsant property of both the three carbamacepin pharmaceutical preparations and the raw material, in mice, after Pentilenetetrazol (PlZ), a convulsant chemical. Thus, the percentage of inhibition of the lethal effect of PTZ with four doses of each preparation was determined. With this experimental model, the results indicate that there are no significant differences among the four preparations under study in the capacity to antagonize the PTZ maximal dose effect. Therefore, it is suggested that they would not differ in their anticonvulsant properties.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Comparative study of the pharmacologic potency of four preparations of Carbamacepin

El objeto del presente estudio fue evaluar la potencia anticonvulsivante de tres formulaciones farmacéuticas de Carbamacepina y de la materia prima sin procesamiento, en ratones, frente al Pentilenetetrazol (PTZ), una sustancia química convulsivante. Para ello se determinó el porcentaje de inhibición del efecto letal de PTZ con 4 dosis de cada formulación y de la materia prima. En este modelo experimental, los resultados señalan que no hay diferencias significativas en la capacidad de antagonizar el efecto de la dosis máxima de PTZ entre las 4 preparaciones bajo estudio. Por lo tanto, se sugiere que no diferirían en su efecto anticonvulsivante.The aim of the present study was to assess the anticonvulsant property of both the three carbamacepin pharmaceutical preparations and the raw material, in mice, after Pentilenetetrazol (PlZ), a convulsant chemical. Thus, the percentage of inhibition of the lethal effect of PTZ with four doses of each preparation was determined. With this experimental model, the results indicate that there are no significant differences among the four preparations under study in the capacity to antagonize the PTZ maximal dose effect. Therefore, it is suggested that they would not differ in their anticonvulsant properties.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Metadata in a Digital Library of Periodicals

This paper is devoted to the analysis and design of a digital library of periodicals and academic journals. This kind of libraries pertains to a set of applications about historical structured documents, which has been identified in our previous work [Ara96][Ara97]. We have addressed these applications from the point of view of temporal object-oriented databases, so that the whole multimedia contents of the academic journals are stored into a document database preserving the same logical organisation as given by publishers. In this context, the database query language is in charge of extracting the global or partial contents of stored journals by describing the wished features such as authors, keywords, dates as well as, their temporal relationships. In our model, metadata plays an outstanding role. Firstly, the concept of metadata provides a well-suited framework to model and classify the composition relationships between documents and their temporal properties. By the other hand, the use of metadata improves the expressive power of both document definition and query languages

Multidimensional Fibrillatory Waves Analysis for Improved Electrical Cardioversion Outcome Prediction in Persistent Atrial Fibrillation

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] The European Society of Cardiology guidelines recommend electrical cardioversion (ECV) as a rhythm control strategy in persistent atrial fibrillation (AF). Although being able to initially restore sinus rhythm in most patients, mid- and long-term AF recurrence rates are high. In this context, anticipation of ECV outcome is interesting to rationalize the management of AF patients. To this end, several parameters have been recently proposed for atrial activity (AA) characterization, such as fibrillatory wave amplitude (FWA), dominant frequency (DF) and sample entropy (SEn). These indices have revealed promising results, but have been mainly computed from lead V1, thus discarding spatial information from the remaining leads. Hence, this work explores whether a multidimensional extension of these parameters can improve ECV outcome prediction. Results showed that multidimensional parameters provided more balanced values of sensitivity and specificity than unidimensional ones. While FWA and DF showed similar discriminant ability among both approaches, multivariate SEn improved the discriminant ability of its univariate version by 5%, thus predicting 80% of the ECV procedures correctly. Consequently, whereas multivariate extension of linear parameters did not reveal new predictive information, multidimensional entropy analysis was able to quantify novel AA dynamics, which have been helpful in improving ECV outcome prediction.This research was funded by projects DPI2017-83952-C3 from MINECO/AEI/FEDER EU, SBPLY/17/180501/000411 from "Junta de Castilla la Mancha" and AICO/2019/036 from "Generalitat Valenciana".Cirugeda, EM.; Calero, S.; Plancha, E.; Enero, J.; Rieta, JJ.; Alcaraz, R. (2020). Multidimensional Fibrillatory Waves Analysis for Improved Electrical Cardioversion Outcome Prediction in Persistent Atrial Fibrillation. IEEE. 1-4. https://doi.org/10.1109/EHB50910.2020.9280226S1

Prediction of Early Failure in Electrical Cardioversion of Atrial Fibrillation Using Refined Multiscale Entropy

[EN] In the management of atrial fibrillation (AF), electrical cardioversion (ECV) is a common treatment. Although its initial success rate is high, many patients present AF recurrence after some weeks or months. Hence, being able to identify patients at low chance of mid-term sinus rhythm maintenance is important for a rationale therapeutic strategy. To this end, several parameters assessing fibrillatory (f-) waves have been introduced, however, with limited predictive ability. Moreover, the cardiovascular system exhibits nonlinear dynamics at different time-scales that these indices do not account for. Hence, the present work evaluates the ability of the multiscale entropy (MSE) analysis of the f-waves to improve preoperative forecasts of ECV outcome. Both traditional MSE and a refined version (RMSE) were applied to the main f waves component obtained for standard lead V1. As a reference, previously proposed predictors were also computed. Results revealed that RMSE was able to anticipate AF recurrence after 1 month of ECV with an accuracy around 78%. Moreover, a Naive Bayes model combining previous parameters and RMSE indices reported a discriminant ability 10% higher than single metrics. It could then be concluded that analysis of nonlinear dynamics at large time-scales can enhance ECV outcome predictions.This research was funded by projects: DPI2017-83952-C3 from MINECO/AEI/FEDER EU, SBPLY/17/180501000411 from Junta de Castilla la Mancha and AICO/2019/036 from Generalitat Valenciana.Cirugeda, EM.; Calero, S.; Hidalgo, VM.; Enero, J.; Rieta, JJ.; Alcaraz, R. (2020). Prediction of Early Failure in Electrical Cardioversion of Atrial Fibrillation Using Refined Multiscale Entropy. IEEE. 1-4. https://doi.org/10.1109/EHB50910.2020.9280294S1

Evaluating MDC with incentives in P2PTV systems

The popularity of P2P video streaming is raising the interest of broadcasters, operators and service providers. Concretely, mesh-pull based P2P systems are the most extended ones. Despite these systems address scalability efficiently, they still present limitations that difficult them to offer the same user experience in comparison with traditional TV. These ones are mainly the freeriding effect, long start-up delays and the impact of churn and bandwidth heterogeneity. In this paper we study the performance of Multiple Description Coding (MDC) combined with the use of incentives for redistribution in order to mitigate some of them by means of simulations. Simulation results show that the use of MDC and incentive-based scheduling strategies improve the overall performance of the system. Moreover, an extended version of the P2PTVSim simulator has been developed to support MDC and incentives.Peer Reviewe