A5015234124- Cardiac electrophysiology and arrhythmias
- Cardiac Arrhythmias and Treatments
- Atrial Fibrillation Management and Outcomes
- Cardiac pacing and defibrillation studies
- Ion channel regulation and function
- ECG Monitoring and Analysis
- Cardiovascular Effects of Exercise
- Neuroscience and Neural Engineering
- Tissue Engineering and Regenerative Medicine
- Hemodynamic Monitoring and Therapy
- Cardiac Fibrosis and Remodeling
- Electrochemical Analysis and Applications
- Machine Learning in Healthcare
- Muscle activation and electromyography studies
- Anomaly Detection Techniques and Applications
- Electrospun Nanofibers in Biomedical Applications
- Nuclear Receptors and Signaling
- Time Series Analysis and Forecasting
- Cellular Mechanics and Interactions
- Hydrogen embrittlement and corrosion behaviors in metals
Schweizerische Ärztegesellschaft für Psycholytische Therapie
2023
University of Bern
2013-2017
International Centre for Genetic Engineering and Biotechnology
2016
Centro de Cirugía de Mínima Invasión Jesús Usón
2016
École Polytechnique Fédérale de Lausanne
2007-2014
École Normale Supérieure - PSL
2007
Gene Signal (Switzerland)
2007
Antiarrhythmic drugs are widely used to treat patients with atrial fibrillation (AF), but the mechanisms conveying their variable effectiveness not known. Recent data suggested that paired like homeodomain-2 transcription factor (PITX2) might play an important role in regulating gene expression and electrical function of adult left atrium (LA). After determining LA PITX2 AF requiring rhythm control therapy, authors assessed effects Pitx2c on electrophysiology effect antiarrhythmic drugs....
Background— TGF-β 1 (transforming growth factor-β ) importantly contributes to cardiac fibrosis by controlling differentiation, migration, and collagen secretion of myofibroblasts. It is still elusive, however, which extent alters the electrophysiological phenotype myofibroblasts cardiomyocytes whether it affects proarrhythmic myofibroblast–cardiomyocyte crosstalk observed in vitro. Methods Results— Patch-clamp recordings cultured neonatal rat ventricular revealed that , applied for 24 48...
Fibrotic myocardial remodeling is typically accompanied by the appearance of myofibroblasts (MFBs). In vitro, MFBs were shown to slow conduction and precipitate ectopic activity following gap junctional coupling cardiomyocytes (CMCs). To gain further mechanistic insights into this arrhythmogenic MFB-CMC crosstalk, we performed numerical simulations in cell-based high-resolution two-dimensional tissue models that replicated experimental conditions. Cell dimensions determined using confocal...
AimsMyofibroblasts (MFBs) as appearing in the myocardium during fibrotic remodelling induce slow conduction following heterocellular gap junctional coupling with cardiomyocytes (CMCs) bioengineered tissue preparations kept under isometric conditions. In this study, we investigated hypothesis that strain developed diastolic filling of heart chambers may modulate MFB-dependent conduction.
Kinetics of Atrial Repolarization Alternans. Introduction: alternans (Re‐ALT), a beat‐to‐beat alternation in action potential repolarization, promotes dispersion wavebreaks, and reentry. Recently, Re‐ALT has been shown to play an important role the transition from rapid pacing atrial fibrillation (AF) humans. The detailed kinetics Re‐ALT, however, not reported so far. We developed chronic free‐behaving ovine model study as function rate. Methods: Thirteen sheep were chronically implanted...
Repolarization Alternans and Atrial Remodeling Introduction Paroxysmal atrial fibrillation (AF) may be triggered by intermittent tachycardia, ultimately lead to persistent AF. However, the mechanisms which tachycardia promotes sustained AF are not well understood. Methods Results Eight sheep were chronically implanted with 2 pacemakers for recording of broadband right unipolar electrograms, delivery electrophysiological stimulation protocols tachycardia. Right kinetics activation recovery...
Bipolar voltage (BV) electrograms for left atrial (LA) substrate characterization depend on catheter design and electrode configuration.
Hundreds of genetic variants in SCN5A, the gene coding for pore-forming subunit cardiac sodium channel, Na(v) 1.5, have been described patients with channelopathies as well individuals from control cohorts. The aim this study was to characterize biophysical properties 2 naturally occurring 1.5 variants, p.R689H and p.R689C, found arrhythmias individuals. In addition, motivated by finding variant a family sudden death (SCD) children. When expressed HEK293 cells, most current (I(Na)) both were...
Background Although entrainment mapping is an established approach to atypical atrial flutter ablation, postpacing intervals shorter than tachycardia cycle length (difference between interval and [dPPI] <0 ms) remain of unknown significance. We sought compare anatomic electrophysiological properties sites with dPPI <0, dPPI=0–30, >30 ms. Methods studied 24 noncavotricuspid isthmus–dependent macroreentrant in 19 consecutive patients. Ultra high-density electroanatomic activation maps...
Experimental models have reported conflicting results regarding the role of dispersion repolarization in promoting atrial fibrillation (AF). Repolarization alternans, a beat-to-beat alternation action potential duration, enhances when propagation velocity is involved.In this work, original electrophysiological parameters were analysed to study AF susceptibility chronic sheep model pacing-induced AF. Two pacemakers implanted, each with single right lead. Right depolarization and waves...
The correspondence between the firing rates of atrial myocytes during fibrillation and dominant frequencies observed in Fourier spectra corresponding surface ECG signals was studied. observations were based on simulated using a biophysical model atria volume conduction effects thorax. Different substrates for AF generated, each resulting different type dynamics. results indicate that full spectrum yields more information complexity particular variant than analysis just its frequency. same...
We explore the feasibility of obtaining a spatially resolved picture [Formula: see text] inward currents ([Formula: text]) in multicellular cardiac tissue by differentiating optically recorded transients that accompany propagating action potentials. Patterned growth strands neonatal rat ventricular cardiomyocytes were stained with indicators Fluo-4 or Fluo-4FF. Preparations stimulated at 1 Hz, and high spatiotemporal resolution text], 2 kHz analog bandwidth) photodiode array. Signals...
Abstract Background Bipolar voltage (BV) electrograms for left atrial (LA) substrate characterization depend on catheter design and electrode configuration. The aim of the study was to investigate relationship between BV amplitude (BVA) using four different catheters identify their specific LA cutoffs scar healthy tissue. Methods Consecutive high-resolution electroanatomic mapping performed a multipolar Orion (Orion-map), duo-decapolar variable circular (Lasso-Map) an irrigated focal...
Interdisciplinary collaboration between physicians and engineers is now widespread in fundamental clinical studies, due to the increasing complexity of physiological problems tackled, development novel measurement devices data analysis techniques. The present work a clear illustration this fact. In study that triggered it, elaborate experiments on an animal model yielded large amounts perturbed by unavoidable interferences, phenomenon interest had elusive nature. This thesis describes...
<h3>Background and objectives</h3> Polymorphisms close to the PITX2 gene on chromosome 4q25 are associated with incident recurrent atrial fibrillation (AF). Carriers of variant rs10033464 respond relatively well antiarrhythmic drug therapy sodium channel blockers. To test whether altered mRNA expression alters electrophysiological effect blockers, we studied flecainide (Flec) in hearts mice heterozygous Pitx2c deletion, a model for reduced Pitx2 AF susceptibility. <h3>Methods</h3> We...
Background: Myocardial infarction (MI) causes cell death and triggers hypertrophic remodeling of surviving cardiomyocytes, resulting in heart failure.A therapeutic approach aiming at inducing cardiomyocyte proliferation while inhibiting the response would improve cardiac function prevent MI-induced failure.By bioinformatics analyses, we identified miR-106b 25 cluster to potentially target a network negative cycle regulators, as well series prohypertrophic factors, indicating this microRNA...
Abstract Funding Acknowledgements Type of funding sources: Private company. Main source(s): The study was supported by an investigator sponsored grant (Boston Scientific). Background Bipolar voltage electrograms (BVE) for left atrial (LA) substrate characterization strongly depend on the catheter design and electrode configuration. Purpose aim to compare bipolar obtained from atrium using four different established mapping catheters deduce individual catheter-specific cut-offs scar healthy...