ECG Lead System Practice Test

The augmented lead that is unipolar and records the potential between the left arm and the central terminal is indeed the lead designated as aVL. This lead functions by measuring the electrical activity of the heart from the perspective of the left arm, effectively evaluating the heart's lateral wall.

In the context of the unipolar lead system, aVL is derived by calculating the voltage difference between the left arm electrode and the average potential of the other limb electrodes, representing what is known as the central terminal. This central terminal is typically computed using a combination of the right arm and left leg leads to provide a reference point that allows for the assessment of electrical activity from the left arm.

Understanding the specific function of aVL is crucial for interpreting ECGs accurately, especially when it comes to diagnosing conditions affecting the lateral regions of the heart. This makes recognizing aVL’s unique recording characteristics essential for anyone studying or working with ECGs.