Acute myocardial infarction (AMI) is diagnosed if: (1) the ECG traces satisfy an ST Elevation Myocardial Infarction (STEMI) criterion and the ECG traces do not indicate the subject has a confounding cardiac condition, or (2) the ECG traces satisfy the STEMI criterion and the ECG traces also indicate the subject has the confounding cardiac condition and a three-dimensional vector cardiograph (3D-VCG) signal generated from the ECG traces includes an ST vector in the ST segment of the 3D-VCG signal and a terminal QRS vector of maximum magnitude in a terminal portion of the QRS complex of the 3D-VCG signal for which the angle between the ST vector and the terminal QRS vector is less than a threshold angle, e.g. in the range [130°, 170°] inclusive. The confounding cardiac condition may be bundle branch block (BBB), left ventricular hypertrophy (LVH), or interventricular conduction delay (IVCD).
