Abstract
We carried out 3D vector measurement of magneto-cardiograms (MCGs) of normal subjects and subjects with myocardial infarction (MI) or premature ventricular contraction (PVC), using a 3D second-order gradiometer connected to 39-channel SQUIDs, which can detect the magnetic field components perpendicular to the chest wall (Bz) and tangential to the chest wall (Bx, By) simultaneously. We used principal component analysis in order to compare the frequency characteristics in the MCG waveforms of MI, PVC, and normal subjects. The results showed that the frequencies in the MCG waveforms of MI and PVC subjects were dominated by lower frequencies (less than 10 Hz) than in normal MCGs, and that the score proportion characteristic of Bx was different from those characteristic of Bz and By.
