Question

A standard three-lead frontal plane ECG is taken from a person with a normal heart. The peak amplitude of R wave is

• A. Greatest in lead I
• B. Greatest in lead II
• C. Greatest in lead III
• D. Equal in all the leads

Hint:

Lead II aligns with the heart's electrical axis, showing the tallest R wave in normal ECG.

Answer 1

The Correct Option is B

In a normal heart, the electrical axis is directed from the right shoulder to the left leg, aligning most closely with Lead II. This results in the highest positive deflection (R wave) in Lead II among the standard limb leads.