In a normal heart, the depolarization vector of the right ventricle proceeds in which direction?

• A. Down and to the right
• B. Up and to the right
• C. Down and to the left
• D. Up and to the left

Answer: (A)

The depolarization vector of the ventricles in a normal heart is directed toward the apex, i.e., downward and to the left side of the chest. This reflects the overall ventricular axis: the left ventricle, being larger and more posterior, dominates the mean direction of depolarization, pulling the net vector toward the inferior left chest. The right ventricle’s activation is smaller in influence, so the overall result is not toward the right or upward. Therefore, the best description is down and to the left.