II and III, I and II, I and aVF, aVL and aVF, and from a vectorial combination of leads I, II, and III. The group means were similar, but there were large intraindividual differences of the QRS axis (up to ±350) and, to a somewhat lesser degree, of the T axis between the different lead combinations. Hypothetically, the axes from different lead combinations should be identical. The intraindividu...