Search results for " arrhythmia"
showing 10 items of 79 documents
Development and Long-Term Follow-Up of an Experimental Model of Myocardial Infarction in Rabbits
2020
Simple Summary Ischemic heart disease is one of the leading causes of death. A series of processes occur during acute myocardial infarction that contribute to the development of ventricular dysfunction, with subsequent heart failure and ventricular arrhythmias, which account for most episodes of sudden cardiac death in these patients. These complications are associated with the adverse cardiac remodeling that occurs during the healing process following an acute episode. The remodeling causes the appearance of a substrate that can trigger life-threatening arrhythmias, such as tachycardia and/or ventricular fibrillation. The development of experimental models for analyzing the basic mechanism…
SYNCOPE AND ARRHYTHMIAS IN PAEDIATRIC AGE
2007
SYNCOPE AND ARRHYTHMIAS IN PAEDIATRIC AGE
Model-Based Evaluation of Methods for Respiratory Sinus Arrhythmia Estimation
2021
OBJECTIVE: Respiratory sinus arrhythmia (RSA) refers to heart rate oscillations synchronous with respiration, and it is one of the major representations of cardiorespiratory coupling. Its strength has been suggested as a biomarker to monitor different conditions, and diseases. Some approaches have been proposed to quantify the RSA, but it is unclear which one performs best in specific scenarios. The main objective of this study is to compare seven state-of-the-art methods for RSA quantification using data generated with a model proposed to simulate, and control the RSA. These methods are also compared, and evaluated on a real-life application, for their ability to capture changes in cardior…
Complexity analysis of experimental cardiac arrhythmia
2014
International audience; To study the cardiac arrhythmia, an in vitro experimental model and Multielectrodes Array (MEA) are used. This platform serves as an intermediary of the electrical activities of cardiac cells and the signal processing / dynamics analysis. Through it the extracellular potential of cardiac cells is acquired, allowing a real-time monitoring / analyzing. Since MEA has 60 electrodes / channels dispatched in a rectangular region, it allows real-time monitoring and signal acquisition on multiple sites. The in vitro experimental model (cardiomyocytes cultures from new-born rats' heart) is directly prepared on the MEA. This carefully prepared culture has similar parameters as…
Quantification of synchronization during atrial fibrillation by Shannon entropy: Validation in patients and computer model of atrial arrhythmias
2005
Atrial fibrillation (AF), a cardiac arrhythmia classically described as completely desynchronized, is now known to show a certain amount of synchronized electrical activity. In the present work a new method for quantifying the level of synchronization of the electrical activity recorded in pairs of atrial sites during atrial fibrillation is presented. A synchronization index (Sy) was defined by quantifying the degree of complexity of the distribution of the time delays between sites by Shannon entropy estimation. The capability of Sy to discriminate different AF types in patients was assessed on a database of 60 pairs of endocardial recordings from a multipolar basket catheter. The analysis…
Mechanism of Sinoatrial Node Dysfunction in a RyR 2 R420Q Mouse Model Ofcatecholaminergic Polymorphic Ventricular Tachycardia
2017
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a genetic disease characterized by stress-induced syncope and/or sudden death in young individuals with structurally normal heart. More than 150 mutations located in the cardiac Ca2+ release channel (type-2 ryanodine receptor, RyR2) gene are related to CPVT. Besides ventricular tachycardia (VT) under stress, sinoatrial node (SAN) dysfunction is frequently observed in CPVT patients. However, the cellular mechanisms remain underexplored. We created a KI mice model bearing a mutation in the N-terminal portion of the RyR2 found in a CPVT family, RyR2(R420Q). ECGs were recorded in KI and WT littermates in resting condition and after…
Morphometry and comparative histology of sinus and atrioventricular nodes in humans and pigs and their relevance in the prevention of nodal arrhythmi…
2019
The cardiac conduction system is a network structure that allows the initiation and fast propagation of electrical impulses that trigger the electrical depolarization of the myocardial tissue. The purpose of this work is to study the histological and morphometric characteristics of the different components of the sinus and atrioventricular nodes in humans and pigs and their relationship with supraventricular arrhythmias. In this study, we describe the morphometry of the sinus and atrioventricular nodes of 10 adult humans and 10 pig hearts. A computerized morphometric study has been carried out, where we determined the number of cells that compose the nodes as well as different parameters re…
Non-invasive localization of atrial ectopic beats by using simulated body surface P-wave integral maps
2017
Non-invasive localization of continuous atrial ectopic beats remains a cornerstone for the treatment of atrial arrhythmias. The lack of accurate tools to guide electrophysiologists leads to an increase in the recurrence rate of ablation procedures. Existing approaches are based on the analysis of the P-waves main characteristics and the forward body surface potential maps (BSPMs) or on the inverse estimation of the electric activity of the heart from those BSPMs. These methods have not provided an efficient and systematic tool to localize ectopic triggers. In this work, we propose the use of machine learning techniques to spatially cluster and classify ectopic atrial foci into clearly diffe…
In silico pace-mapping: prediction of left vs. right outflow tract origin in idiopathic ventricular arrhythmias with patient-specific electrophysiolo…
2019
Abstract Aims A pre-operative non-invasive identification of the site of origin (SOO) of outflow tract ventricular arrhythmias (OTVAs) is important to properly plan radiofrequency ablation procedures. Although some algorithms based on electrocardiograms (ECGs) have been developed to predict left vs. right ventricular origins, their accuracy is still limited, especially in complex anatomies. The aim of this work is to use patient-specific electrophysiological simulations of the heart to predict the SOO in OTVA patients. Methods and results An in silico pace-mapping procedure was designed and used on 11 heart geometries, generating for each case simulated ECGs from 12 clinically plausible SOO…