The Relationship between the Anatomic Position of the Heart and the Electrocardiogram

A Criticism of "Unipolar" Electrocardiography

GRANT, ROBERT P. M.D.

From the Clinic of General Medicine and Experimental Therapeutics of the National Heart Institute, Section of Cardiodynamics, U. S. Public Health Service Hospital, Baltimore, Md. (GRANT)

Circulation 7(6):p 890-902, June 1953.

Using a method for identifying precisely the lie of the ventricular structures in the body at autopsy, the anatomic position of the heart was compared with the directions of the QRS electrical forces in a large number of subjects with and without heart disease. While the mean QRS axis varied through 180 degrees in these subjects, the anatomic position of the left ventricle varied less than 45 degrees. No instances of significant rotation of the heart around its long axis were encountered, and it is shown that the unipolar electrocardiographic criteria for position and rotation of the heart have little validity. An explanation for the axis deviations of ventricular hypertrophy is offered.