scholarly journals Regional segmentation of ventricular models to achieve repolarization dispersion in cardiac electrophysiology modeling

2015 ◽  
Vol 31 (8) ◽  
pp. e02718 ◽  
Author(s):  
L. E. Perotti ◽  
S. Krishnamoorthi ◽  
N. P. Borgstrom ◽  
D. B. Ennis ◽  
W. S. Klug
Keyword(s):  
Cardiac Electrophysiology ◽  
Electrophysiology Modeling

scholarly journals Ionic parameters identification of an inverse problem of strongly coupled PDE’s system in cardiac electrophysiology using Carleman estimates

2019 ◽  
Vol 14 (2) ◽  
pp. 202 ◽  
Author(s):  
Yassine Abidi ◽  
Mourad Bellassoued ◽  
Moncef Mahjoub ◽  
Nejib Zemzemi
Keyword(s):  
Inverse Problem ◽  
Cardiac Electrophysiology ◽  
Reaction Diffusion ◽  
Cellular Membrane ◽  
Stability Estimate ◽  
Strongly Coupled ◽  
Carleman Type ◽  
Membrane Models ◽  
Electrophysiology Modeling ◽  
Ionic Exchanges

In this paper, we consider an inverse problem of determining multiple ionic parameters of a 2 × 2 strongly coupled parabolic–elliptic reaction–diffusion system arising in cardiac electrophysiology modeling. We use the bidomain model coupled to an ordinary differential equation (ODE) system and we consider a general formalism of physiologically detailed cellular membrane models to describe the ionic exchanges at the microscopic level. Our main result is the uniqueness and a Lipschitz stability estimate of the ion channels conductance parameters of the model using subboundary observations over an interval of time. The key ingredients are a global Carleman-type estimate with a suitable observations acting on a part of the boundary.

scholarly journals Cellular cardiac electrophysiology modeling with Chaste and CellML

2015 ◽  
Vol 5 ◽  
Author(s):  
Jonathan Cooper ◽  
Raymond J. Spiteri ◽  
Gary R. Mirams
Keyword(s):  
Cardiac Electrophysiology ◽  
Electrophysiology Modeling

High-Frequency Cardiac Electrophysiology

2019 ◽  
Author(s):  
Pavel Jurak ◽  
Josef Halamek ◽  
Pavel Leinveber ◽  
Filip Plesinger ◽  
Ivo Viscor ◽  
...  
Keyword(s):  
High Frequency ◽  
Cardiac Electrophysiology

Subclinical Thyroid Dysfunction and the Risk of Cardiovascular Disease

2020 ◽  
Vol 26 (43) ◽  
pp. 5617-5627
Author(s):  
Mirjana Stojković ◽  
Miloš Žarković
Keyword(s):  
Cardiovascular Disease ◽  
Risk Factor ◽  
Cardiac Electrophysiology ◽  
Vascular System ◽  
Density Lipoprotein ◽  
Thyroid Stimulating Hormone ◽  
Normal Limits ◽  
Developing Heart ◽  
Treatment Indications ◽  
Increased Risk

The prevalence of subclinical hypothyroidism (SH) is 3-10%. The prevalence of subclinical hyperthyroidism (SHr) is 0.7-9.7%. Thyroid hormones affect cardiac electrophysiology, contractility, and vasculature. SH is associated with an increased risk of coronary heart disease (CHD), especially in subjects under 65. SHr seems to be associated with a slightly increased risk of CHD and an increase in CHD-related mortality. Both SH and SHr carry an increased risk of developing heart failure (HF), especially in those under 65. Both SH and SHr are associated with worse prognoses in patients with existing HF. SH is probably not associated with atrial fibrillation (AF). SHr, low normal thyroid-stimulating hormone (TSH) and high normal free thyroxine (FT4) are all associated with the increased risk of AF. An association between endothelial dysfunction and SH seems to exist. Data regarding the influence of SHr on the peripheral vascular system are conflicting. SH is a risk factor for stroke in subjects under 65. SHr does not increase the risk of stroke. Both SH and SHr have an unfavourable effect on cardiovascular disease (CVD) and all-cause mortality. There is a U-shaped curve of mortality in relation to TSH concentrations. A major factor that modifies the relation between subclinical thyroid disease (SCTD) and mortality is age. SH increases blood pressure (BP). SHr has no significant effect on BP. Lipids are increased in patients with SH. In SHr, high-density lipoprotein cholesterol and lipoprotein( a) are increased. SCTD should be treated when TSH is over 10 mU/l or under 0.1 mU/l. Treatment indications are less clear when TSH is between normal limits and 0.1 or 10 mU/L. The current state of knowledge supports the understanding of SCTD’s role as a risk factor for CVD development. Age is a significant confounding factor, probably due to age-associated changes in the TSH reference levels.

scholarly journals Machine-readable Yin–Yang imbalance: traditional Chinese medicine syndrome computer modeling based on three-dimensional noninvasive cardiac electrophysiology imaging

2019 ◽  
Vol 47 (4) ◽  
pp. 1580-1591 ◽  
Author(s):  
Wei Cen ◽  
Ralph Hoppe ◽  
Aiwu Sun ◽  
Hongyan Ding ◽  
Ning Gu
Keyword(s):  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Electrical Activity ◽  
Computer Modeling ◽  
Cardiac Electrophysiology ◽  
Three Dimensional ◽  
Mathematical Physics ◽  
Syndrome Differentiation ◽  
Physics Model ◽  
Machine Readable

Objectives The principal diagnostic methods of traditional Chinese medicine (TCM) are inspection, auscultation and olfaction, inquiry, and pulse-taking. Treatment by syndrome differentiation is likely to be subjective. This study was designed to provide a basic theory for TCM diagnosis and establish an objective means of evaluating the correctness of syndrome differentiation. Methods We herein provide the basic theory of TCM syndrome computer modeling based on a noninvasive cardiac electrophysiology imaging technique. Noninvasive cardiac electrophysiology imaging records the heart’s electrical activity from hundreds of electrodes on the patient’s torso surface and therefore provides much more information than 12-lead electrocardiography. Through mathematical reconstruction algorithm calculations, the reconstructed heart model is a machine-readable description of the underlying mathematical physics model that reveals the detailed three-dimensional (3D) electrophysiological activity of the heart. Results From part of the simulation results, the imaged 3D cardiac electrical source provides dynamic information regarding the heart’s electrical activity at any given location within the 3D myocardium. Conclusions This noninvasive cardiac electrophysiology imaging method is suitable for translating TCM syndromes into a computable format of the underlying mathematical physics model to offer TCM diagnosis evidence-based standards for ensuring correct evaluation and rigorous, scientific data for demonstrating its efficacy.

scholarly journals Space-time multilevel Monte Carlo methods and their application to cardiac electrophysiology

2021 ◽  
Vol 433 ◽  
pp. 110164
Author(s):  
S. Ben Bader ◽  
P. Benedusi ◽  
A. Quaglino ◽  
P. Zulian ◽  
R. Krause
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Methods ◽  
Cardiac Electrophysiology ◽  
Space Time ◽  
Multilevel Monte Carlo

Stability and performance of the EnSite Precision cardiac mapping system for electrophysiology mapping and ablation procedures: results from the EnSite Precision observational study

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
D Lin ◽  
B Glover ◽  
J Colley ◽  
B Thibault ◽  
C.M Steinberg ◽  
...  
Keyword(s):  
Observational Study ◽  
Real World ◽  
Cardiac Electrophysiology ◽  
Median Number ◽  
System Stability ◽  
Cardiac Mapping ◽  
Average Force ◽  
Mapping System ◽  
Respiratory Change ◽  
Electrophysiology Mapping

Abstract Background The EnSite Precision™ Cardiac Mapping System is a catheter navigation and mapping system capable of displaying the three-dimensional (3D) position of conventional and sensor enabled electrophysiology catheters, as well as displaying cardiac electrical activity as waveform traces and dynamic 3-D maps of cardiac chambers. Objective The EnSite Precision™ Observational Study was designed to quantify and characterize the use of the EnSite Precision™ Cardiac Mapping System for mapping and ablation of cardiac arrhythmias in a real-world environment and to evaluate procedural and subsequent clinical outcomes. Methods 1065 patients were enrolled at 38 centers in the U.S. and Canada between 2017–2018. Eligible subjects were adults undergoing a cardiac electrophysiology mapping and radiofrequency ablation procedures using the EnSite Precision™ System. Results Of 989 patients who completed the protocol, a geometry was created in 936 (94.7%). Most initial maps were created using Automap (n=545, 67.0%) or a combination of Automap and manually mapping (n=151, 18.6%). Median time to create an initial map was 9.0 min (IQR 5.0–15.0), with a median number of used mapping points per minute of 92.7 (IQR 30.0–192.0). During ablation, AutoMark was used in 817 (82.6%) of procedures. The most frequent metrics for lesion color were Impedance Drop or Impedance Drop Percent (45.5% combined), time (23.9%) and average force (14.2%). At Canadian sites where LSI was an option, it was used as the color metric in 87 (45.8%) of cases (10.6% overall). The EnSite System was stable throughout 79.7% (n=788 of 989) of procedures. Factors affecting stability were respiratory change (n=88 of 989, 8.9%), patient movement (n=73, 7.4%), CS Positional Reference dislodgement (n=32, 3.2%), and cardioversion (n=19, 1.9%). Conscious sedation was used in 189 (19.1%) of patients. Acute success was reached based on the pre-defined endpoints for the procedure in 97.4% (n=963) of cases. Conclusion In a real-world study analysis, the EnSite Precision™ mapping system was associated with a high prevalence of acute procedural success, low mapping times, and high system stability. Funding Acknowledgement Type of funding source: None

scholarly journals Into a Fluoroless Future: an Appraisal of Fluoroscopy-Free Techniques in Clinical Cardiac Electrophysiology

2021 ◽  
Vol 23 (4) ◽  
Author(s):  
Christopher S. Purtell ◽  
Ryan T. Kipp ◽  
Lee L. Eckhardt
Keyword(s):  
Cardiac Electrophysiology ◽  
Imaging Technique ◽  
Early Experience ◽  
Intracardiac Echocardiography ◽  
Electroanatomic Mapping ◽  
Supporting Evidence ◽  
Device Implantation ◽  
Mri Guidance ◽  
Fluoroscopic Imaging ◽  
Mapping Systems

Abstract Purpose of Review There are risks to both patients and electrophysiology providers from radiation exposure from fluoroscopic imaging, and there is increased interest in fluoroscopic reduction. We review the imaging tools, their applications, and current uses to eliminate fluoroscopy. Recent Findings Multiple recent studies provide supporting evidence for the transition to fluoroscopy-free techniques for both ablations and device implantation. The most frequently used alternative imaging approaches include intracardiac echocardiography, cardiac MRI guidance, and 3D electroanatomic mapping systems. Electroanatomic mapping and intracardiac echocardiography originally used to augment fluoroscopy imaging are now replacing the older imaging technique. The data supports that the future of electrophysiology can be fluoroscopy-free or very low fluoroscopy for the vast majority of cases. Summary As provider and institution experience grows with these techniques, many EP labs may choose to completely forego the use of fluoroscopy. Trainees will benefit from early experience with these techniques.

scholarly journals Automated Framework for the Inclusion of a His–Purkinje System in Cardiac Digital Twins of Ventricular Electrophysiology

2021 ◽  
Author(s):  
Karli Gillette ◽  
Matthias A. F. Gsell ◽  
Julien Bouyssier ◽  
Anton J. Prassl ◽  
Aurel Neic ◽  
...  
Keyword(s):  
Cardiac Electrophysiology ◽  
Ventricular Myocardium ◽  
Activation Patterns ◽  
Purkinje System ◽  
Digital Twins ◽  
Emergent Features ◽  
Ventricular Activation ◽  
Endocardial Layer ◽  
Right Ventricular Apical Pacing ◽  
Electrocardiogram Ecg

AbstractPersonalized models of cardiac electrophysiology (EP) that match clinical observation with high fidelity, referred to as cardiac digital twins (CDTs), show promise as a tool for tailoring cardiac precision therapies. Building CDTs of cardiac EP relies on the ability of models to replicate the ventricular activation sequence under a broad range of conditions. Of pivotal importance is the His–Purkinje system (HPS) within the ventricles. Workflows for the generation and incorporation of HPS models are needed for use in cardiac digital twinning pipelines that aim to minimize the misfit between model predictions and clinical data such as the 12 lead electrocardiogram (ECG). We thus develop an automated two stage approach for HPS personalization. A fascicular-based model is first introduced that modulates the endocardial Purkinje network. Only emergent features of sites of earliest activation within the ventricular myocardium and a fast-conducting sub-endocardial layer are accounted for. It is then replaced by a topologically realistic Purkinje-based representation of the HPS. Feasibility of the approach is demonstrated. Equivalence between both HPS model representations is investigated by comparing activation patterns and 12 lead ECGs under both sinus rhythm and right-ventricular apical pacing. Predominant ECG morphology is preserved by both HPS models under sinus conditions, but elucidates differences during pacing.

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