BPS2026 – The magnetic signature of cardiac alternans: A computational study

Sudden cardiac death remains one of the major causes of mortality worldwide, creating an urgent need for innovative diagnostic strategies. Advances in quantum magnetometry are opening new possibilities for noninvasive monitoring of cardiac activity under both physiological and pathological conditions. In this study, we introduce a theoretical framework to investigate cardiac magnetic dynamics using simplified 1D and 2D geometries mimicking cardiac fibers and tissue. Our formulation couples thermo-electric models of cardiac electrophysiology with Maxwell’s equations for the magnetic field, leveraging the advantages of simple 1D and 2D geometries. Within this framework, we analyze the emergence and evolution of spatially concordant and discordant alternans, comparing magnetic field-based markers with conventional indicators such as APD and (∂V/∂t)MAX in both homogeneous and heterogeneous domains. Our findings indicate that magnetic markers can serve as a alternative to standard electrical metrics for alternans characterization. In particular, magnetic restitution curves enable precise detection of alternans onset. In the heterogeneous case, the magnetic field representation also captures tissue inhomogeneities that remain hardly detectable using APD alone. In conclusion, this work establishes a magnetic field-oriented approach for the analysis of cardiac electrophysiology, offering a valuable tool for the study of concordant and discordant alternans as well as for the identification of tissue heterogeneities.