When preparing to obtain a 12-lead ECG, the 'LL' and 'RL' electrodes should be placed:

When preparing to obtain a 12-lead ECG, the 'LL' and 'RL' electrodes should be placed:

• A. On the lower abdomen.
• B. On either side of the chest.
• C. Anywhere on the arms.
• D. On the thighs or ankles.

Answer: (D)

In a 12-lead ECG, limb electrodes create the limb leads and provide a reference point for the circuit. One limb electrode, the right leg (ground), is used as a grounding reference, while the left leg serves as the second limb electrode feeding the limb leads. If you can’t place the limb electrodes on the arms, you can relocate the leg electrodes to the thighs or ankles without losing the essential signals. This setup keeps the circuit intact and preserves the differential voltages that form the limb leads, ensuring accurate recording of the ECG.

In a 12-lead ECG, limb electrodes create the limb leads and provide a reference point for the circuit. One limb electrode, the right leg (ground), is used as a grounding reference, while the left leg serves as the second limb electrode feeding the limb leads. If you can’t place the limb electrodes on the arms, you can relocate the leg electrodes to the thighs or ankles without losing the essential signals. This setup keeps the circuit intact and preserves the differential voltages that form the limb leads, ensuring accurate recording of the ECG.