Certified Registered Nurse Anesthetist (CRNA) Practice Exam

Which leads are considered inferior leads in electrocardiography?

1. V5, V6

2. I, aVL

3. II, III, aVF

4. II, V2, V4

The correct answer is: II, III, aVF

The leads that are considered inferior leads in electrocardiography are those that primarily monitor the electrical activity of the inferior wall of the heart, which is supplied by the right coronary artery in most individuals. The leads reflecting this area are II (Lead II), III (Lead III), and aVF (augmented Vector Foot). Lead II records the electrical activity from the right arm to the left leg, which captures the heart's activity in a way that highlights the inferior wall. Lead III also captures similar inferior wall activity but measures from the left arm to the left leg. aVF provides a view upward toward the heart from the feet, also focusing on the inferior wall. This recognition of inferior leads is essential for diagnosing conditions like inferior myocardial infarctions, where the inferior wall is affected. Understanding the placement of these leads clarifies their role in identifying cardiac issues that may arise from problems in the inferior part of the heart. The other mentioned leads do not focus on the inferior wall. For example, V5 and V6 are more related to the lateral wall, while I and aVL are focused on the high lateral aspect of the left ventricle. Lead II, V2, and V4 involve different regions, with V2 and