A mathematical and physical basis for heart-vector projection concepts is presented and its significance for current practices in frontal-plane and spatial electrocardiography is discussed. Assumptions underlying the theory are stated and utilized to derive a general relationship between the heart dipole and the potentials it produces in the body. Specific equations are given for unipolar and bipolar leads and the Wilson central-terminal voltage. Coefficients determined experimentally for human torso models differ markedly from those that stem from Einthoven's hypothesis. Einthoven's equilateral triangle represents a special case of the general theory. Geometric interpretations are applied to a quantitative frontal-plane example, to the Wilson central-terminal voltage and extended to the concept of an image surface corresponding to the human body surface.
- Received November 10, 1953.
- © 1954 American Heart Association, Inc.