Introduction: Magnetocardiography (MCG), which measures the magnetic component of the heart's electrical activity, offers an alternative approach for analyzing changes induced by coronary artery disease (CAD). This study examines several parameters that quantify spatial and temporal aspects of cardiac magnetic signals in CAD.
Materials and methods: MCGs were registered at rest in 144 subjects, aged 58.3 +/- 9.8 years: 50 healthy subjects, 43 CAD patients without myocardial infarction (MI), 36 with MI, and 15 with spontaneous episodes of ventricular tachycardia (VT). Spatial characteristics of magnetic field maps (MFM), quantified using their centers of gravity, included MFM orientation and trajectory plots. Spatio-temporal analysis was performed by determining the spatial distribution of the QT interval.
Results: In CAD patients, MFM orientation during the QT interval deviated from normal in 67% of patients without MI and in 85% of patients with MI. Trajectory plots deviated from those of the normal group, with deviation increasing with disease severity. Quantifying the distribution of QT interval duration using a smoothness index demonstrated a significant difference between the values for healthy subjects and non-MI patients, as well as MI patients with and without VT (p < 0.001).
Conclusion: The results reported demonstrate that disturbances in cardiac electrogenesis resulting from CAD may be assessed using MCG signal analysis.