What type of infarction is indicated by Q waves in leads V1, V2, V3, or V4?

What type of infarction is indicated by Q waves in leads V1, V2, V3, or V4?

• A. Inferior infarction
• B. Anterior infarction
• C. Lateral infarction
• D. Subendocardial infarction

Answer: (B)

Q waves in leads V1, V2, V3, or V4 are indicative of an anterior infarction. This is due to the anatomical location and blood supply to the heart. The anterior wall of the left ventricle is primarily supplied by the left anterior descending artery (LAD). When this artery is occluded or there's significant ischemia due to a blockage, it leads to necrosis in the anterior wall of the heart, which is reflected as Q waves in the corresponding leads that monitor that region.

The presence of Q waves signifies that there has been significant myocardial damage and indicates a progression from an acute to a chronic stage of infarction, reflecting prior myocardial infarction. This is distinct from other types of infarctions, which present with Q waves in different lead configurations, thereby helping clinicians localize the affected area of the heart. Understanding these lead patterns is crucial for proper diagnosis and treatment planning in patients with suspected myocardial infarction.