Which leads signify an inferior infarction when Q waves are present?

Which leads signify an inferior infarction when Q waves are present?

• A. V1, V2, V3
• B. I and AVL
• C. II, III, and AVF
• D. V5, V6

Answer: (C)

An inferior infarction on an EKG is typically indicated by pathological Q waves present in the inferior leads, which are leads II, III, and aVF. These leads correspond to the electrical activity of the inferior wall of the heart, which is supplied by the right coronary artery in most individuals. The presence of Q waves in these leads indicates necrosis of the myocardial tissue in that area due to ischemia or infarction.

In contrast, the other options refer to leads that do not correspond to the inferior aspect of the heart. The leads V1, V2, and V3 primarily reflect the anterior and septal regions. Leads I and aVL focus on the lateral aspect of the heart, while leads V5 and V6 also assess the lateral wall. Therefore, the selection of leads II, III, and aVF as indicators of inferior infarction is accurate because they specifically reflect the inferior wall's electrical activity and changes associated with infarction in that region.