What is the purpose of the I, II, and III leads in a 12 lead EKG?

What is the purpose of the I, II, and III leads in a 12 lead EKG?

• A. To measure chest lead activity
• B. To record unipolar measurements
• C. To represent bipolar limb leads
• D. To analyze heart rate only

Answer: (C)

The purpose of the I, II, and III leads in a 12-lead EKG is to represent bipolar limb leads. These leads provide valuable information regarding the electrical activity of the heart by measuring the voltage differences between two points on the body. In this context, lead I measures the potential difference between the right arm and the left arm, lead II measures the difference between the right arm and left leg, and lead III measures the difference between the left arm and left leg. This bipolar configuration helps in assessing the heart's electrical axis and provides important insights into various cardiac conditions.

The bipolar limb leads are essential for evaluating the heart's rhythm and overall cardiac function, making them foundational components of the 12-lead EKG system. Each lead contributes uniquely to the overall representation of the heart’s electrical activity, allowing healthcare professionals to detect abnormalities effectively.