Which lead is considered to be grounded?

The right leg lead (RL) is considered to be grounded in the context of electrocardiography. This grounding helps to eliminate electrical noise that can interfere with the accurate recording of the heart's electrical activity. By designating the right leg as a ground, it can help stabilize the measurements taken from the other limb leads (the left arm, right arm, and left leg).

In a standard 12-lead ECG configuration, the right leg does not provide active information about the heart's activity; instead, it serves to complete the circuit. The three limb electrodes (RA, LA, and LL) are the ones that pick up the heart’s electrical signals, while the RL lead provides a reference point that helps to minimize artifacts in the reading due to external electrical interference or patient movement.

This setup is essential in ensuring that the EKG readings reflect the true electrical patterns of the heart, making the RL lead's role as a ground crucial in clinical practice.