…the P wave vector is directed downwards and to the left in the frontal plane and this yields a positive P wave in lead II …

…electrical axis [3]. A frontal plane axis directed toward the positive pole of lead I is designated as 0 degrees. Axes oriented clockwise from this…

…aVR exists at 30° in the frontal plane, according to Figure 2 . Figure 2. The coordinate system presenting the limb leads in the frontal plane…