XYZ data interpreted by a 12-lead computer program using the derived electrocardiogram.

The 12-lead electrocardiogram (ECG) derived from the Frank xyz signals was compared with the conventional 12-lead ECG using the Telemed computer system. In 100 cases studied. Telemed's interpretations were essentially similar in 77, but substantially different in 23. In the 23 cases, interpretations of the derived tracings tended to be more accurate in 14 cases, and less accurate in four cases. In the diagnosis of infarction the probability that the interpretation of the derived tracing will be correct more often was 90%. The better performance may have been related to closer agreement with the vectorcardiogram (VCG). As a substitute for the conventional ECG, the derived ECG offers the prospect of a computerized system that is more practical and more versatile than most currently used systems.