Publications associées à Ectopic beat

Finding information-rich electrocardiographic biomarkers to characterize atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia; it will affect one in four adults worldwide in their lifetime. AF has serious consequences, including drastically increased risk of stroke. Catheter ablation surgery is an established treatmen ...

EPFL2023

Active force generation contributes to the complexity of spontaneous activity and to the response to stretch of murine cardiomyocyte cultures

Stéphanie Lacour

Cardiomyocyte cultures exhibit spontaneous electrical and contractile activity, as in a natural cardiac pacemaker. In such preparations, beat rate variability exhibits features similar to those of heart rate variability in vivo. Mechanical deformations and ...

WILEY2022

A Computational Study of the Electrophysiological Substrate in Patients Suffering From Atrial Fibrillation

Alfio Quarteroni, Andrea Manzoni

In the context of cardiac electrophysiology, we propose a novel computational approach to highlight and explain the long-debated mechanisms behind atrial fibrillation (AF) and to reliably numerically predict its induction and sustainment. A key role is pla ...

FRONTIERS MEDIA SA2021

Implantable Fiber Bragg Grating Sensor for Continuous Heart Activity Monitoring: Ex-Vivo and In-Vivo Validation

Silvestro Micera

Continuous and reliable cardiac function monitoring could improve medication adherence in patients at risk of heart failure. This work presents an innovative implantable Fiber Bragg Grating-based soft sensor designed to sense mechanical cardiac activity. T ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2021

Ventricular response regularity in atrial fibrillation and its relationship to successful catheter ablation

Jean-Marc Vesin, Adrian Luca, Etienne Pruvot

Atrial rate is known to modulate ventricular response during atrial fibrillation (AF). The resulting pulse irregularity translates into widely varying inter-beat intervals (IBIs) extracted from recorded surface electrocardiogram (ECG) activity. In AF, the ...

IEEE2020

Can one detect atrial fibrillation using a wrist-type photoplethysmographic device?

Jean-Marc Vesin, Célestin Leupi, Mathieu Lemay, Sibylle Fallet, Etienne Pruvot, Philippe Renevey

This study aims at evaluating the potential of a wrist-type photoplethysmographic (PPG) device to discriminate between atrial fibrillation (AF) and other types of rhythm. Data from 17 patients undergoing catheter ablation of various arrhythmias were proces ...

SPRINGER HEIDELBERG2019

Noninvasive Stroke Volume Monitoring by Electrical Impedance Tomography

Fabian Braun

In clinical practice it is of vital importance to track the health of a patient's cardiovascular system via the continuous measurement of hemodynamic parameters. Cardiac output (CO) and the related stroke volume (SV) are two such parameters of central inte ...

EPFL2018

Real-Time Probabilistic Heart Beat Classification and Correction for Embedded Systems

David Atienza Alonso, Francisco Javier Rincon Vallejos, Srinivasan Murali, Grégoire Casimir Joseph Surrel

With the emergence of wearable and non-intrusive med- ical devices, one major challenge is the real-time analysis of the acquired signals in real-life and ambulatory con- ditions. This paper presents a lightweight algorithm for on-line heart beat classific ...

2015

Method for detecting abnormalities in an electrocardiogram

David Atienza Alonso, Giovanni Ansaloni, Francisco Javier Rincon Vallejos, Ruben Braojos Lopez, Srinivasan Murali

A method for classification of ECG beats into normal and different categories of abnormal beats. The method comprises the following steps, performed on a computing platform: a. performing a training phase comprising taking as an input one or more ECG beats ...

2015

Influence of heart motion on cardiac output estimation by means of electrical impedance tomography: a case study

Jean-Philippe Thiran, Mathieu Lemay, Fabian Braun, Martin Proença, Michaël Rapin

Electrical impedance tomography (EIT) is a non-invasive imaging technique that can measure cardiac-related intra-thoracic impedance changes. EIT-based cardiac output estimation relies on the assumption that the amplitude of the impedance change in the vent ...

Iop Publishing Ltd2015

Estimation of Blood Pressure and Pulse Transit Time Using Your Smartphone

David Atienza Alonso, Francisco Javier Rincon Vallejos, Srinivasan Murali, Alair Dias Junior

It is widely recognized today that there is an alarming rise of lifestyle-induced chronic diseases (e.g., type II diabetes) in our society. Therefore, a strong need exists for cost-effective and non-invasive devices that can measure blood pressure (BP) to ...

IEEE Computer Society Press2015

Melanocyte-like cells in the heart and pulmonary veins contribute to atrial arrhythmia triggers

Friedrich Beermann, Fang Liu

Atrial fibrillation is the most common clinical cardiac arrhythmia. It is often initiated by ectopic beats arising from the pulmonary veins and atrium, but the source and mechanism of these beats remains unclear. The melanin synthesis enzyme dopachrome tau ...

American Society for Clinical Investigation2009

Activity Level of an Atrial Ectopic Focus Observed Through the Equivalent Dipole: a Biophysical Model

Jean-Marc Vesin, Vincent Jacquemet, Mathieu Lemay, Cédric Duchene

Quantifying the role of atrial ectopic foci in the initiation and the maintenance of atrial fibrillation (AF) is a relevant clinical problem. This study aims at assessing the relation between the activity level of an ectopic focus and the complexity of the ...

2009

Dictionary learning for the sparse modelling of atrial fibrillation in ECG signals

Jean-Marc Vesin, Pierre Vandergheynst, Rémi Gribonval

We propose a new method for ventricular cancellation and atrial modelling in the ECG of patients suffering from atrial fibrillation. Our method is based on dictionary learning. It extends both the average beat subtraction and the sparse source separation a ...

2009

The Role of Atrial Modeling in the Development of ECG Processing Tools

Jean-Marc Vesin, Mathieu Lemay, Cédric Duchene, Laurent Renaud Uldry, Vincent Jacquemet, Lukas Kappenberger

The standard ECG remains the most common non-invasive tool for assessing atrial fibrillation. Specific signal processing techniques have been developed to improve the diagnosis. However, validation of such tools is challenging and comprehensive invasive da ...

2009

Calcium dynamics and vasomotion in arteries subject to isometric, isobaric, and isotonic conditions

Jean-Jacques Meister, Jean-Louis Bény, Roger Sauser, Dominique Seppey, Michèle Koenigsberger

In vitro, different techniques are used to study the smooth muscle cells' calcium dynamics and contraction/relaxation mechanisms on arteries. Most experimental studies use either an isometric or an isobaric setup. However, in vivo, a blood vessel is neithe ...

2008

Stochastic phase oscillator models for circadian clocks

Felix Naef, Jacques Rougemont

Periodic environments like we experience on the surface of planet earth lead living organisms to evolve molecular anticipation devices known a circadian clocks. The word circadian refers to the period of these oscillations which last about (circa) one day ...

Springer2008

Full Spectral Analysis of the Atrial Components in the ECG during Atrial Fibrillation

Lukas Kappenberger, Mathieu Lemay

Clinical standard 12-lead ECG recordings over 5 minutes on patients in atrial fibrillation or in atrial flutter were analyzed. After suppression of the signal components related to ventricular activity, the amplitude spectra of all leads were inspected. Th ...

IEEE2008

Data processing techniques for the characterization of atrial fibrillation

Mathieu Lemay

Atrial fibrillation is the most common sustained cardiac rhythm disturbance, increasing in prevalence with age. During the past 20 years, there has been a 66% increase in hospital admissions related to atrial fibrillation. Neither the natural history of at ...

EPFL2008

Model-based inferences for clinical applications of the ECG

Doctor Macchi reported on the progress of an animal model study of electric propagation initiated by electric stimuli. Doctor Oostendorp first gave an introduction to the inverse problem of cardiac activation time mapping (ATM), the determination of the de ...

Elsevier2007