Leads I, II, and III are categorized as what type of leads?

Leads I, II, and III are categorized as bipolar leads because they measure the electrical difference between two electrodes placed on the body. In these leads, one electrode serves as the positive pole and the other as the negative pole, allowing for the assessment of the heart's electrical activity from different angles. Specifically, Lead I compares the electrical potential between the right arm and left arm, Lead II compares the right arm and left leg, and Lead III compares the left arm and left leg. This configuration provides valuable information about the heart's rhythm and orientation in the frontal plane.

In contrast, unipolar leads, which are not the correct choice, derive their readings from a single positive electrode referenced against a central terminal that averages the electrical activity of the heart. Precordial and chest leads, which are also not correct for this question, refer to a different group of leads that are placed on the chest to provide a horizontal view of the heart's electrical activity. Thus, the classification of leads I, II, and III as bipolar is based on their method of measuring electrical potentials using two electrodes.