Answer to Question 1
Frontal plane leads view the heart from the front of the body as if it were flat. Directions in the frontal plane are superior, inferior, right, and left. Six leads view the heart in the frontal plane. Leads I, II, and III are called standard limb leads. Leads aVR, aVL, and aVF are called augmented limb leads.
Answer to Question 2
hexaxial reference system