Which of the following are considered unipolar limb leads?

Which of the following are considered unipolar limb leads?

• A. aVR, aVL, aVF
• B. I, II, III
• C. V1, V2, V3
• D. V4, V5, V6

Answer: (A)

Unipolar limb leads are specifically designed to measure the electrical activity of the heart from one point relative to a reference point, which allows for a more detailed view of the heart's electrical activity. The leads aVR, aVL, and aVF are classified as unipolar limb leads because they are derived from a single positive electrode placed on the limb while the other electrodes serve as a common ground or reference point.

Each of these leads provides a different angle from which to observe the heart's electrical activity:

• aVR measures the electrical activity from the right arm.

• aVL measures the electrical activity from the left arm.

• aVF measures the electrical activity from the left leg.

The other options consist of bipolar leads or precordial leads, which have different configurations for recording heart activity. Bipolar leads, such as I, II, and III, utilize two electrodes to measure the difference in electrical potential between two points. Precordial leads, such as V1 through V6, are also not classified as unipolar limb leads since they focus on recording activity across the chest rather than from the limbs alone. Thus, the correct identification of unipolar limb leads reaffirms the understanding of how lead placement affects the interpretation of