Relationship between the Electrocardiogram and the Position of the Heart as Determined by Biplane Angiocardiography

Abstract

Anatomic orientation of the heart was determined in 53 patients by selective, biplane angiocardiography, and was compared with the mean electric axis and the location of the transition zone from conventional electrocardiograms. No significant correlation could be demonstrated between (a) the anatomic axis and the electric axis in the frontal plane, or (b) between the electric axis and rotation of the heart about its longitudinal axis, or (c) the location of the interventricular septum and the transition zone of the precordial leads. The electric variations are greater than can possibly be explained by known rotations of the heart about any anatomic axis. The degrees of rotation about the heart's longitudinal axis assumed in the concept of "electrical positions" is beyond the range found in normal or hypertrophied hearts. It is concluded that the electric positions of the heart should be abandoned in favor of direct description in three dimensions of the orientation of the mean electromotive force of the heart. Normal limits should be defined in percentiles or standard deviations.