A method for detecting myocardial abnormality by using a total current-vector calculated from ST-segment deviation of a magnetocardiogram signal

A simple method to determine the state of ischaemia or fibrosis of myocardi al cells has been developed. This method uses the ST wave of 64-channel mag netocardiogram (MCG) signals to calculate three parameters from the current -arrow map of the normal component signal of the MCG. One parameter is a fe tal current vector that is obtained through summation of all current arrows . Another is a variance current vector calculated from the differential vec tor of two total current vectors at different times. The third is a flatnes s factor between the magnitude of the total current vector and the variance current vector. The three parameters are independent of the distance betwe en the heart and the gradiometers. We measured the MCG signals of 29 health y subjects, twenty patients with coronary artery disease (ten with previous myocardial infarction (MI) and ten with angina pectoris (AP)), and eight p atients with cardiomyopathy (four with hypertrophic cardiomyopathy (HCM), t hree with dilated cardiomyopathy (DCM), and one with restrictive cardiomyop athy (RCM)). With our method, none of the healthy subjects tested positive for myocardial abnormalities, while 80% of the MI patients, 50% of the AP p atients, and 100% of the cardiomyopathy patients tested positive. Although further testing is needed, we feel this simple technique enables easy diagn osis of myocardial damage.