Relationship between the anatomical orientation of the interventricular septum and the manifest orientation of ventricular depolarization in dogs.

• Variation in cardiac position lias been frequently suggested as a principal cause for the wide contrast in configuration of electrocardiograms.^ In contrast, both postmortem and biplane angiographic examinations have suggested that there is relatively little actual anatomical variation in the position of the heart or more particularly of the interventricular septum in healthy or diseased man.Unfortunately, orientation has in large part been assessed by inspection or assigned by assumption, and few serious attempts have been made to relate anatomical and electrical position in a quantitative fashion.