The opposing electrode is created by combining other electrodes into a _____, an electrically neutral point to reference the center of the heart.

The opposing electrode is created by combining other electrodes into a _____, an electrically neutral point to reference the center of the heart.

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

Answer: (A)

In unipolar ECG leads, one electrode measures the heart’s electrical activity while the other side uses a reference point that is electrically neutral and closest to the center of the heart. This neutral reference is Wilson’s central terminal, created by combining the potentials from the three limb electrodes (right arm, left arm, left leg) through a resistor network. This summed point serves as a stable reference for the center of the heart, so the chest leads (and the augmented limb leads) can measure the true directional activity of the heart against a neutral background. That’s why this term fits best: it specifically describes the neutral reference point formed from other electrodes. The other options describe lead types or locations but do not name the neutral reference point used for unipolar measurements.

In unipolar ECG leads, one electrode measures the heart’s electrical activity while the other side uses a reference point that is electrically neutral and closest to the center of the heart. This neutral reference is Wilson’s central terminal, created by combining the potentials from the three limb electrodes (right arm, left arm, left leg) through a resistor network. This summed point serves as a stable reference for the center of the heart, so the chest leads (and the augmented limb leads) can measure the true directional activity of the heart against a neutral background. That’s why this term fits best: it specifically describes the neutral reference point formed from other electrodes. The other options describe lead types or locations but do not name the neutral reference point used for unipolar measurements.