Clinical electrocardiography; three-dimensional visual aids to teaching.

Empiric interpretation of the clinical electrocardiogram is no longer adequate. The funamental contributions of Wilson and Goldberger have led to the common clinical use of 12 leadsthree standard, three augmented extremity, and six praecordial. If the interpreter is to gain the most knowledge from the information available in these leads, an understanding of the electrical position of the heart in each instance is essential. Visual aids to the teaching of any spatial principle are of obvious value. Goldberger's book (1949) applies two-dimensional illustrations to the relation of cardiac position and fixed unipolar electrocardiographic leads within the electrical field. This article describes two three-dimensional diagrammatic models of the ventricular heart related to the common fixed leads. One is more applicable to the seminar or individual discussion, the other to the classroom.