Physiology If QRS deflection is large and positive in lead II and 0 in aVL. What is his mean electrical axis in the frontal plane? A 90 degrees B 60 degrees C -60 degrees D -90 degrees 💡 Explanation If QRS deflection is large and positive in lead II and 0 in aVL. What is his mean electrical axis in the frontal plane? ✓ Correct Answer: B. 60 degrees