Which lead measures the electrical activity between the center of the heart and the chest wall where the V1 electrode is placed?

• A. V1
• B. V2
• C. V3
• D. V4

Answer: (A)

The lead that measures the electrical activity between the center of the heart and the chest wall at the location of the V1 electrode is indeed V1. The V1 lead is placed in the fourth intercostal space to the right of the sternum, which allows it to provide a view of the electrical activity of the right atrium and the interventricular septum as well as early depolarization of the ventricles.

This positioning is critical because V1 captures the electrical impulses traveling from the heart’s center toward the right side of the chest wall. The nature of this lead's placement means it primarily reflects the anterior and septal walls of the heart activity, essential for diagnosing conditions that involve these regions.

The other leads listed in the options (V2, V3, V4) each have different placements and therefore different areas of focus in terms of electrical activity. V2 is positioned to measure activity adjacent to V1 but provides a slightly different view, as it is placed on the left side of the sternum. V3 offers an intermediate position between the anterior and lateral aspects, while V4 is placed in the fifth intercostal space at the midclavicular line, focusing more on the left ventricle. Together