What is the placement of Lead V1 in relation to the sternum?

Lead V1 is placed at the fourth intercostal space, just to the right of the sternum. This placement is critical for accurately assessing the heart's electrical activity, particularly the anterior and septal walls of the left ventricle. The location of Lead V1 allows for a clear view of the electrical impulses as they travel through the heart, especially when evaluating for conditions such as STEMI (ST-Elevation Myocardial Infarction) or other cardiac abnormalities.

The fourth intercostal space is the appropriate anatomical landmark because it typically aligns with the height of the heart's chambers relevant to the electrical conduction system. Being positioned just to the right of the sternum places Lead V1 in an optimal position to pick up electrical activity from the right atrium and the right ventricle.

Correct placement of this lead is also essential for improving the accuracy of the 12-lead ECG, which relies on precise anatomical positioning of all leads to provide a comprehensive view of heart function. If V1 were placed incorrectly—for instance, in positions suggested by other choices—it would not adequately reflect the heart's electrical activity and could lead to misinterpretation of the ECG results. Correct placement is pivotal for diagnostics and treatment decisions in emergency and critical care