Augmented leads on an ECG are characterized by what?

• A. Baseline
• B. Leads that measure activity from one electrode at a time and are read larger
• C. Augmented leads
• D. Amplifier

Answer: (C)

Augmented leads are unipolar limb leads (aVR, aVL, aVF). They measure electrical activity from one limb electrode at a time, using a reference formed by the other two limbs (Wilson's central terminal). Because the reference is a composite of two limbs, the signal from the single electrode is smaller, so the ECG machine boosts the gain to make the deflection readable. That boosting is why these leads are called augmented. So the defining idea is unipolar measurement with increased amplification to visualize the waveform. Baseline describes the isoelectric line, and an amplifier is the machine component, not what defines the lead type.