Study of Unipolar Electrogram Morphology in a Computer Model of Atrial Fibrillation

Jacquemet, Vincent; Virag, Nathalie; Ihara, Z.; Dang, Lam; Blanc, Olivier; Zozor, Steeve; Vesin, Jean‐Marc; Kappenberger, Lukas; Henriquez, Craig S.

doi:10.1046/j.1540.8167.90308.x

Cited by 117 publications

(114 citation statements)

References 21 publications

Supporting

Mentioning

101

Contrasting

Order By: Relevance

“…The LA and RA are connected through 3 interatrial connections: the Bachmann's bundle, fossa ovalis, and coronary sinus as observed with simultaneous biatrial noncontact mapping in humans. 13 By assigning different diffusion coefficients, as suggested previously, 8,12 we obtained heterogeneous conduction regions in the atria ( Figure IIB in the online-only Data Supplement). Specifically, the conduction velocities were 65 cm/s in the bulk tissue, 120 cm/s in the fast bundles, and 36 cm/s in the slow-conduction region.…”

Section: Atrial Anatomic Structuresupporting

confidence: 53%

“…Both are within the range of atrial refractory periods in humans 7 and are comparable to previous modeling studies of atrial arrhythmias. 8 …”

Section: Methods the Single-cell Modelmentioning

confidence: 99%

“…8,12 With these assignments, it takes Ϸ110 ms for a sinus wave to activate the whole atria, with the last activation occurring in the lateral posterior region of the LA, where 3 wave fronts converge (Movie I in the online-only Data Supplement). The results are comparable to the observations from previous experiments 7 and simulation studies.…”

Section: Atrial Anatomic Structurementioning

confidence: 99%

“…The results are comparable to the observations from previous experiments 7 and simulation studies. 8,12 …”

Section: Atrial Anatomic Structurementioning

confidence: 99%

“…6 Additionally, for the elevated I Ca,L case in our studies, the maximum slope of the APD restitution is slightly Ͼ1 ( 1C and 1D), as observed in patients with paroxysmal AF 19 and previous modeling studies of AF. 8,10 AFL/AF Induction Mechanism: Discordant Alternans and APD Dispersion…”

Section: L-type Ca 2؉ Current and Restitution Propertiesmentioning

confidence: 99%

See 4 more Smart Citations

Mechanism Underlying Initiation of Paroxysmal Atrial Flutter/Atrial Fibrillation by Ectopic Foci

et al. 2007

View full text Add to dashboard Cite

Background-The mechanisms underlying paroxysmal atrial flutter/atrial fibrillation initiation by ectopic foci from various locations are unclear. Methods and Results-We used parallel computational techniques to study an anatomically accurate 3-dimensional atrial structure incorporating a detailed ionic-current model of an atrial myocyte. At the single-cell level, upregulation of the L-type Ca 2ϩ current I Ca,L steepened restitution curves of action potential duration and conduction velocity compared with the control. Spontaneous firings of ectopic foci, coupled with sinus activity, produced dynamic spatial dispersions of repolarization, including discordant alternans, which caused conduction block and reentry only for the elevated I Ca,L case. For each foci location, a vulnerable window for atrial flutter/atrial fibrillation induction was identified as a function of the coupling interval and focus cycle length. For ectopic foci in the pulmonary veins and left atrium, the site of conduction block and reentry gradually shifted, as a function of coupling interval, from the right atrium to the interatrial area and finally to the left atrium. The size of the vulnerable window was largest for pulmonary vein foci, becoming markedly smaller for right atrial foci, especially those near the sinoatrial node. Conclusions-These findings suggest that a mechanism of dynamically induced repolarization dispersion, especially discordant alternans, underlies the induction of atrial flutter/atrial fibrillation by atrial ectopic foci. The sites and likelihood of reentry induction varied according to ectopic focus location and timing, with the largest vulnerable window corresponding to the pulmonary vein region.

show abstract

Section: Atrial Anatomic Structuresupporting

confidence: 53%

“…Both are within the range of atrial refractory periods in humans 7 and are comparable to previous modeling studies of atrial arrhythmias. 8 …”

Section: Methods the Single-cell Modelmentioning

confidence: 99%

Section: Atrial Anatomic Structurementioning

confidence: 99%

“…The results are comparable to the observations from previous experiments 7 and simulation studies. 8,12 …”

Section: Atrial Anatomic Structurementioning

confidence: 99%

Section: L-type Ca 2؉ Current and Restitution Propertiesmentioning

confidence: 99%

See 3 more Smart Citations

Mechanism Underlying Initiation of Paroxysmal Atrial Flutter/Atrial Fibrillation by Ectopic Foci

et al. 2007

View full text Add to dashboard Cite

show abstract

Atrial Fibrillation and Atrial Flutter

Hornero

2006

Wiley Encyclopedia of Biomedical Engineering

View full text Add to dashboard Cite

Nonpharmacologic treatments of atrial fibrillation and atrial flutter potentially offer therapy, sparing patients the long‐term risks of antiarrhythmic drug therapy. For patients with typical atrial flutter, contemporary catheter ablation techniques afford cure rates in excess of 85%. For patients with atrial fibrillation, surgical Maze procedure and catheter‐based procedures emulating aspects of the surgical Maze technique can today offer cure rates around 75%. However, additional research and technological development is necessary to further define and refine the best effective procedure. For the present, because each therapeutic alternative carries its own unique set of risks, side effects, and benefits, patients selection remains of critical importance.

show abstract

Modeling of Atrial Fibrillation

Virag¹,

Jacquemet²,

Kappenberger³

2012

Cardiac Mapping

Self Cite

View full text Add to dashboard Cite

Computer modeling of atrial fibrillation (AF) is considered today as a potentially effective tool for better understanding AF mechanisms and for the development of therapeutic options. Computer models are based on an integrative approach, from the molecule to the patient, incorporating data about cell electrophysiology, cell-to-cell coupling and atrial anatomy. The link to clinical experiments is provided by the computation of endocardial electrograms or surface electrocardiograms (ECG). In this chapter we describe how modeling can be used to study different forms of AF and to evaluate therapies such as antiarrhythmic drugs, ablation and antitachycardia pacing. The ultimate goal is the development of patient-specific models in order to test AF therapies in the model before applying it to the patient.

show abstract

Study of Unipolar Electrogram Morphology in a Computer Model of Atrial Fibrillation

Abstract: Analysis of the amplitude and symmetry of unipolar atrial electrograms can provide information about the electrophysiologic substrate maintaining AF.

Cited by 117 publications

References 21 publications

Mechanism Underlying Initiation of Paroxysmal Atrial Flutter/Atrial Fibrillation by Ectopic Foci

Mechanism Underlying Initiation of Paroxysmal Atrial Flutter/Atrial Fibrillation by Ectopic Foci

Atrial Fibrillation and Atrial Flutter

Modeling of Atrial Fibrillation

Contact Info

Product

Resources

About