AEMCA Practice Exam

Which leads on a 12-lead ECG are considered septal leads?

1. V1 and V2

2. V3 and V4

3. ll, lll, and avF

4. V5 and V6

The correct answer is: V1 and V2

The septal leads in a 12-lead ECG are identified as V1 and V2. These leads are placed over the anterior wall of the heart, specifically over the interventricular septum. When examining the voltage and the morphology of the QRS complexes in these leads, it becomes clear that they provide valuable information regarding the electrical activity that occurs in the septal region during heart contraction. V1 is positioned in the fourth intercostal space to the right of the sternum, while V2 is located in the same intercostal space on the left side. The positioning of these leads enables them to capture the changes in electrical potential produced by depolarization of the septal myocardium, which is crucial for identifying conditions such as left or right bundle branch block and various forms of ischemia localized to the septal area. In contrast, the other options represent different areas of the heart: V3 and V4 primarily monitor the anterior wall; II, III, and aVF reflect the inferior wall; while V5 and V6 are focused on the lateral aspect of the heart. Thus, the significance of leads V1 and V2 as the septal leads is underscored by their direct representation of electrical activity in the