Calculated using the hexaxial reference system that shows the frontal view of the electrical activity of the heart via six limb leads (aVR, aVL, aVF, 1, 2, 3). Easily remembered when represented as: (The horizontal reference system uses the six precordial leads V1‐V6 (+/‐ V4R) to show the horizontal view of the electrical activity of… Read More »Axis