Clinical Observations with an Orthogonal Lead System

Orthogonal electrocardiographic leads of 85 normal and 104 abnormal subjects obtained with a new lead system were examined for the counterparts of clinically significant findings in conventional 12-lead electrocardiograms. Most of the findings judged significant in conventional leads had easily recognizable counterparts in orthogonal leads. Excluding findings suggestive of ventricular enlargement, the conventional tracings of 40 subjects showed QRS abnormalities, and counterparts of these were identified in the orthogonal leads of all but one subject. Counterparts of findings suggesting ventricular enlargement could not be evaluated, since the range of normal variation of orthogonal leads obtained with the system used has not been established in quantitative terms. Conventional records of 99 subjects showed abnormalities of the S-T segments or T waves or both, and recognizable abnormalities of these portions of the curves were present in the orthogonal leads of 97 of the subjects.