Clinical utility of magnetocardiography in cardiology for the detection of myocardial ischemia

Magnetic field maps from (A) subjects without ischemia, showing a bipolar field map throughout the cardiac cycle, and (B) patients with acute coronary syndrome in whom a distorted, fragmented or multipolar field map characterizes active myocardial ischemia. Maps were recorded with a 15-channel magnetometry device and display the magnetic field distribution at the point of maximum rate of change between the Q and R peaks (QR) and between the R and S peaks (RS).

The dipoles observed in subjects without ischemia are generally aligned in the same direction and have only a single positive (red) and single negative (blue) pole. The images from ischemic patients are generally more complex. A wider spread of angles and pole to pole distance, and the presence of more than two peaks are features that generally indicate ischemia.