Which lead provides the best view of the lateral wall of the heart?

The reason Leads I and aVL provide the best view of the lateral wall of the heart is due to their anatomical positioning and electrical orientation. In electrocardiography, each lead provides a different perspective on the heart's electrical activity.

Leads I and aVL are both positioned to capture the electrical signals from the lateral aspect of the left ventricle. Lead I measures the difference in electrical potential between the right arm and the left arm, while aVL is oriented towards the left arm, focusing on the left lateral wall. This configuration allows these leads to effectively visualize and record the electrical activity occurring in the lateral walls of the heart, making them particularly useful for detecting issues such as ischemia or infarction in that region.

In contrast, the other leads mentioned do not provide the same perspective on the lateral wall. For instance, Lead II primarily looks at the inferior wall of the heart, Lead V1 focuses on the right ventricle and the septal area, and Lead III also views the inferior wall. Therefore, Leads I and aVL stand out as the optimal choice for assessing the lateral wall of the heart.