Which lead is considered the most right-sided limb lead?

The most right-sided limb lead is aVR. This lead provides a view of the electrical activity of the heart from the right arm's perspective, focusing on the upper right quadrant of the heart. In the context of the limb leads, aVR is positioned to primarily capture electrical activity that moves towards the right arm, which is significant for detecting abnormalities that may originate in the right side of the heart or in the right precordial area.

aVR is derived by taking the average of the potentials from the left arm and left leg and comparing that to the potential at the right arm, which gives it its unique right-sided orientation. This positioning makes it useful for diagnosing certain conditions, such as right-sided heart strain or other right-sided abnormalities, that may not be as easily identifiable with the other limb leads.

In contrast, other leads like Lead II and aVF provide viewpoints that are oriented towards the inferior and left-sided aspects of the heart, while Lead V6 is located on the left lateral area of the chest, making them less suitable for assessing the right side directly. Therefore, recognizing aVR as the most right-sided limb lead is key to understanding the spatial arrangement of the leads and their clinical significance in EKG interpretations.