What defines unipolar leads?

Unipolar leads are characterized by recording electrical activity from a single location or pole. This means that the lead measures the electrical potential at a specific point on the body, with a reference being made against a common ground, typically located elsewhere on the body. In the context of electrocardiography (ECG), unipolar leads are often used to capture the heart's electrical activity at one specific site, allowing for a focused view of the heart's functioning from that perspective.

This definition emphasizes the specificity of unipolar leads compared to other types of leads, such as bipolar leads. In bipolar leads, measurements are made between two distinct points, capturing the difference in electrical potential between them, which provides a broader view of the heart's activity. Furthermore, while recording the electrical activity of the heart is a characteristic of both unipolar and bipolar leads, the defining feature of unipolar leads is their singular focus on one pole, making the chosen answer accurate in distinguishing this concept.