What changes in which leads may indicate ischemia in the presence of RBBB?

The correct answer about indicating ischemia in the presence of right bundle branch block (RBBB) is the lateral leads (V4, V5, V6). In instances of RBBB, the electrical conduction through the right ventricle is delayed, which can mask changes that typically suggest ischemia. However, ischemic changes may still be detected in the lateral leads due to other factors.

Lateral leads, which assess the left lateral aspect of the heart, can reveal ST-segment changes that are indicative of ischemia. Such changes may still manifest in the lateral leads despite the presence of RBBB, as these leads can show signs of subendocardial ischemia or other abnormalities associated with coronary artery issues.

In contrast, while other leads play a role in overall cardiac assessment, they may not demonstrate the same specificity for identifying ischemic changes in the context of RBBB. The anterior leads primarily reflect issues related to the anterior wall but may be confounded by the right bundle branch block. The inferior leads typically relate to the inferior wall and tend to indicate different pathology. Septal leads can also be affected by RBBB, leading to difficulty in interpreting ischemia signs. Thus, the lateral leads are key for assessing ischemic challenges in the