Background: Brugada syndrome (BrS) is characterized by dynamic ST-elevations in right precordial leads and increased risk of ventricular fibrillation and sudden cardiac death. As the mechanism underlying ST-elevation and malignant arrhythmias is controversial computational modeling can aid in exploring the disease mechanism. Thus we aim to test the main competing hypotheses ('delayed depolarization' vs. 'early repolarization') of BrS in a whole-heart computational model.
Methods: In a 3D whole-heart computational model, delayed epicardial RVOT activation with local conduction delay was simulated by reducing conductivity in the epicardial RVOT. Early repolarization was simulated by instead increasing the transient outward potassium current (I) in the same region. Additionally, a reduction in the fast sodium current (I) was incorporated in both models.
Results: Delayed depolarization with local conduction delay in the computational model resulted in coved-type ST-elevation with negative T-waves in the precordial surface ECG leads. 'Saddleback'-shaped ST-elevation was obtained with reduced substrate extent or thickness. Increased I simulations showed early repolarization in the RVOT with a descending but not coved-type ST-elevation. Reduced I did not show a significant effect on ECG morphology.
Conclusions: In this whole-heart BrS computational model of both major hypotheses, realistic coved-type ECG resulted only from delayed epicardial RVOT depolarization with local conduction delay but not early repolarizing ion channel modifications. These simulations provide further support for the depolarization hypothesis as electrophysiological mechanism underlying BrS.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10924145 | PMC |
http://dx.doi.org/10.1016/j.ijcha.2024.101373 | DOI Listing |
Sci Adv
December 2024
Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA.
Untethered electrical stimulation or pacing of the heart is of critical importance in addressing the pressing needs of cardiovascular diseases in both clinical therapies and fundamental studies. Among various stimulation methods, light illumination-induced electrical stimulation via photoelectric effect without any genetic modifications to beating cells/tissues or whole heart has profound benefits. However, a critical bottleneck lies in the lack of a suitable material with tissue-like mechanical softness and deformability and sufficient optoelectronic performances toward effective stimulation.
View Article and Find Full Text PDFJ Cardiovasc Magn Reson
December 2024
Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, United States.
Background: Contemporary 0.55T MRI is promising for fetal MRI, due to the larger bore, reduced safety concerns, lower acoustic noise, and improved fast imaging capability. In this work, we explore improved fetal cardiac MRI (CMR) without relying on any synchronizing devices, prospective, or retrospective gating.
View Article and Find Full Text PDFCurr Med Imaging
November 2024
Division of Pediatric Cardiology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, USA.
Background: Three-dimensional (3D) whole-heart magnetic resonance imaging (MRI) is an excellent tool to check the heart anatomy of patients with congenital and acquired heart disease. However, most 3D whole-heart MRI acquisitions take a long time to perform, and the sequence used is susceptible to banding artifacts.
Purpose: To validate an unsupervised neural network that can reduce acquisition time and improve image quality for 3D whole-heart MRI by superresolving low-resolution images.
Magn Reson Med
February 2025
School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK.
Magn Reson Med
February 2025
Department of Radiology and Biomedical Imaging, Yale School of Medicine, Yale University, New Haven, Connecticut, USA.
Purpose: To develop a new method for free-breathing 3D extracellular volume (ECV) mapping of the whole heart at 3 T.
Methods: A free-breathing 3D cardiac ECV mapping method was developed at 3 T. T mapping was performed before and after contrast agent injection using a free-breathing electrocardiogram-gated inversion recovery sequence with spoiled gradient echo readout.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!