A new method of displaying the electrocardiogram is described. In this method, the voltages obtained from the precordial leads are presented in a three-dimensional from rather than the conventional two-dimensional metod of plotting voltage-versus-time, for each lead. The display is formed on a cathode ray tube with the time varying along the horizontal coordinate and electrode position along the vertical coordinate. The brightness at any point on the display is determined by the ECG voltage at that time and for that electrode position. A preliminary comparison of the displays obtained from a normal patient and from a patient with an acute myocardial infarction showed specific and easily recognizable differences. The method appears especially advantageous for use by non-cardiologists (e.g. cardiac care nurses in a cardiac care unit.) The distinctive patterns produced by certain abnormalities may be more easily recognizale in the single pictorial display than in the multiple leads of the conventional ECG tracing.