COMPARISON OF DIFFERENT SYSTEMS OF VECTORCARDIOGRAPHY

It is usual for various investigators to use their own system of vectorcardiography. Such a system is characterized by the place of the electrodes and the way in which the vectorcardiogram is deduced from the potential differences obtained. At present the system according to Duchosal and Sulzer (1949) and the one proposed by Wilson et al. (1947) are much in use. The equilateral tetrahedron proposed by the latter is a generalization of the equilateral triangle of Einthoven et al. (1913). In addition the present authors have proposed and used another fundamentally different method, based on the following line of thought. By this method, the principle of which is physically well founded (1946), the vectorcardiogram may be deduced from three potential differences. That is to say, if the electromotive force of the heart may be considered as that of a single dipole, there will be a linear relation between each potential difference Vp-Vq and the three orthogonal components X, Y, Z of the heart vector: