Certified Clinical Medical Assistant CCMA Practice Test

Which of the following groups of EKG leads are bipolar?

1. Leads aVR, aVL, aVF

2. Leads I, II, III

3. Leads V1, V2, V3

4. Leads V4, V5, V6

The correct answer is: Leads I, II, III

Bipolar leads in an EKG are defined as those that measure the electrical potential difference between two separate electrodes placed on the body. In this context, leads I, II, and III are indeed classified as bipolar leads. Lead I measures the potential difference between the left arm and right arm, lead II measures the potential difference between the left leg and right arm, and lead III measures the potential difference between the left leg and left arm. Each of these leads provides valuable information about the heart’s electrical activity from different angles, contributing to a comprehensive view of cardiac health. The other groups listed do not fall under the category of bipolar leads. The leads aVR, aVL, and aVF represent augmented unipolar leads, as they measure the electrical activity from a single electrode relative to a combined reference point, typically considered as a zero potential. Meanwhile, V1, V2, V3, V4, V5, and V6 are considered precordial or chest leads, and they are unipolar leads that also measure voltage from a single point without considering a second electrode to create a potential difference.