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Impact of electric spatially discordant alternans on cardiac magnetic field

Martina Nicoletti1,2,*, Anna Crispino1,*, Alessandro Loppini3,4,†, Alessio Gizzi1, Letizia Chiodo1,4, Christian Cherubini5,6, and Simonetta Filippi1,4

  • *These authors contributed equally to this work.
  • †Contact author: a.loppini@unicampus.it
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Phys. Rev. E 112, 024405 – Published 8 August, 2025

DOI: https://doi.org/10.1103/ys62-2n7g

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 an alternative perspective by characterizing SDA through their magnetic field signatures. Using a one-dimensional idealized cardiac fiber model, we demonstrate that magnetic-field measurements effectively detect SDA and temperature-dependent changes in cardiac action potentials, offering a noninvasive alternative to conventional electrophysiological metrics. Our results reveal that the spatial organization of SDA is mirrored in the distribution of the magnetic field, with SDA nodes clearly identifiable via spatial mapping. Notably, magnetic restitution curves exhibit a distinct pattern from action potential duration (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 alternative avenues for biomagnetic monitoring of arrhythmic risk.

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Phys. Rev. E 112, 024405– Published 8 August, 2025
  • Received 17 February 2025
  • Accepted 30 June 2025
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