Impact of Electric Spatially Discordant Alternans on Cardiac Magnetic Field

TL;DR

This study demonstrates that magnetic field measurements can non-invasively detect spatially discordant alternans in cardiac tissue, providing a new diagnostic approach for arrhythmia risk assessment.

Contribution

The paper introduces a novel method of characterizing SDA through magnetic field signatures, offering an alternative to electrical indicators and enhancing arrhythmia diagnostics.

Findings

Magnetic field measurements effectively detect SDA.

Magnetic restitution curves differ from APD-based indicators.

SDA nodes are identifiable via magnetic spatial mapping.

Abstract

Spatially discordant alternans (SDA) play a crucial role in cardiac arrhythmogenesis by creating steep repolarization gradients facilitating conduction block and reentry. While traditionally studied using electrical indicators, this work provides a novel perspective by characterizing SDA through their magnetic field signatures. Using a one-dimensional cardiac fiber model, we demonstrate that magnetic field measurements effectively detect SDA and temperature dependent changes in cardiac action potentials, offering a non-invasive alternative to conventional electrophysiological metrics. Our results reveal that the spatial organization of SDA is mirrored in the magnetic field distribution, with SDA nodes clearly identifiable via spatial mapping. Notably, magnetic restitution curves exhibit a distinct pattern from APD-based indicators, closely following the dynamics of the action potential upstroke. These findings establish the cardiac magnetic field as a powerful diagnostic tool for detecting SDA, opening new avenues for biomagnetic monitoring of arrhythmic risk.