SPECIAL ARTICLE

Abstract

The diagnostic classification of the ECG waveform can be performed either by visual inspection of the electrocardiogram or by a set of mathematical-statistical decision rules programmed into a computer. It can be demonstrated that if the visual inspection technique is used, the 12-lead ECG will be superior to three scalar orthogonal vectorcardiographic leads. Plane projection vector loops lack accurate data display. If computer techniques are used, suitable decision regions of the instantaneous heart vector will provide accurate decision rules on a three-lead system. Neither the 12-lead system nor the three-orthogonal lead system makes use of all the information available on the body surface. A detailed electrical torso mapping would be required if this information proves to be of diagnostic significance. Misclassification in electrocardiographic diagnosis may be due to (1) failure of electrical events to reflect hemodynamic, anatomic, or biochemical changes; (2) loss of information between the cardiac generator and the body surface; (3) inadequate data display; (4) inadequate mathematical-statistical decision regions; and (5) insufficient number of teaching samples or inadequate independent evidence.