Comparison of electric- and magnetic- cardiograms produced by myocardial ischemia in models of the human ventricle and torso

Myocardial ventricular ischemia arises from the lack of blood supply to the heart, which may cause abnormal excitation wave conduction and repolarization patterns in the tissue, leading to cardiac arrhythmias and even sudden death. Current diagnosis of cardiac ischemia by the 12-lead electrocardiogram (ECG) has limitations as they are insensitive in many cases and may show unnoticeable differences compared to normal patterns. As the magnetic field provides extra information of cardiac excitation and is more sensitive to tangential currents to the surface of the chest, whereas the electric field is more sensitive to radial currents, it has been hypothesized that the magnetocardiogram (MCG) may provide a complementary methodto the ECG in ischemic diagnosis. However, it is unclear yet about the differences in the sensitivity of the ECG and MCG signals to ischemic conditions. The aim of this study was to investigate such differences by using multi-scale biophysically detailed computational models of the human ventricles and torso model, to simulate normal and ischemic conditions.