A Direct Experimental Study of Three Systems of Spatial Vectorcardiography

Abstract

Three commonly used systems of vectorcardiography are compared on an absolute and direct quantitative basis in terms of equations, geometric interpretations, scalar leads and vectorcardiograms, using experimental results obtained on an accurate, three-dimensional homogeneous torso model of the human subject with a dipole fixed in position in the center of the heart. It is concluded that the accuracy of the three systems, as presently used, is unsatisfactory and that further consideration of the systems of Duchosal and Grishman is questionable because of excessive intrinsic errors. Certain chance properties of the Wilson tetrahedron enable standardization modifications which lead to fairly accurate results for some dipole positions, and this system also possesses other features which appear to be desirable. The applicability of the results and conclusions to the human subject depends upon the degree to which the human heart may be represented by a fixed-position dipole and the degree to which human body electrical inhomogeneities influence body surface potentials.