Since only the positive electrode is polarized, these leads are considered _____ _____

Since only the positive electrode is polarized, these leads are considered _____ _____

• A. Unipolar leads
• B. Bipolar leads
• C. Central terminal leads
• D. Monitoring leads

Answer: (A)

The concept being tested is the difference between unipolar and bipolar ECG leads. Unipolar leads use a single active (positive) electrode and a distant reference point. Because only one electrode is actively recording the heart’s electrical activity and the reference is a fixed, distant point (not another nearby electrode), these leads are described as unipolar. The chest leads (V1–V6) and the augmented limb leads (aVR, aVL, aVF) are examples, since their readings come from one recording site against a composite reference rather than between two distinct electrodes. In contrast, bipolar leads measure the voltage between two active electrodes, each contributing to the signal, which is why they’re not labeled unipolar.

The concept being tested is the difference between unipolar and bipolar ECG leads. Unipolar leads use a single active (positive) electrode and a distant reference point. Because only one electrode is actively recording the heart’s electrical activity and the reference is a fixed, distant point (not another nearby electrode), these leads are described as unipolar. The chest leads (V1–V6) and the augmented limb leads (aVR, aVL, aVF) are examples, since their readings come from one recording site against a composite reference rather than between two distinct electrodes.

In contrast, bipolar leads measure the voltage between two active electrodes, each contributing to the signal, which is why they’re not labeled unipolar.