In a 12-lead EKG, which lead primarily views the inferior wall of the heart?

The lead that primarily views the inferior wall of the heart is Lead II. This lead is positioned in such a way that it captures electrical activity coming from the inferior portion of the heart, specifically the areas supplied by the right coronary artery in right-dominant systems. Lead II is oriented from the right arm to the left leg, providing a good view of the atrial and ventricular activity as it reflects the depolarization wave moving toward it from the inferior wall.

Leads I and V3, while they provide valuable information, do not focus on the inferior wall. Lead I is positioned to view the lateral wall, primarily assessing the left atrium and left ventricle from the left arm perspective. Lead V3, located on the precordial area towards the center of the chest, assesses the anterior wall and provides views of the interventricular septum rather than the inferior wall. Lead V5, positioned in the left anterior axillary line, generally captures lateral wall activity and anterior wall transitions. Hence, Lead II is the most appropriate choice for viewing the inferior wall of the heart.