A method of determining an ischemic event includes the steps of: monitoring and storing an initial electrocardiogram vector signal (x, y, z) of a known non-ischemic condition over the QRS, ST and T wave intervals calculating and storing a J-point of the vector signal and a maximum magnitude of a signal level over the T wave interval monitoring a subsequent electrocardiogram vector signal over the QRS, ST and T wave intervals measuring and storing the magnitude (Mag.) of the vector difference between a subsequent vector signal and the initial vector signal measuring and storing the angle (Ang.) difference between a subsequent vector and the initial vector at points regressing a line from points about 25 milliseconds prior to the J point and about 60 milliseconds after the J-point and determining the slope of the regression line and the deviation of the angle difference of the regression line regressing a line from points about 100 milliseconds prior to the maximum magnitude of the signal level over the T wave interval and determining the slope of the regressing line and the deviation of the angle difference of the regression line and comparing the slope and deviation of the lines from the J point and the T wave interval to a set of known values to determine the presence of an ischemic event.
