What is the appearance of significant Q waves in leads associated with anterior infarction?

• A. Shallow and narrow
• B. Deep and wide
• C. Positive deflections
• D. Completely absent

Answer: (B)

Significant Q waves in leads associated with an anterior infarction are characterized by being deep and wide. This is because they represent a loss of muscle mass in the area of the heart that has been affected by ischemia or infarction; when cells die, their electrical activity diminishes, leading to the development of these Q waves. In the case of anterior myocardial infarction, the Q waves appear in the precordial leads (V1 to V3 or V4) and exhibit a pronounced depth and width, indicating extensive damage. This is a crucial finding on an EKG as it helps to confirm the diagnosis of a myocardial infarction and to assess the severity of the damage.

Other options describe characteristics that do not align with significant Q waves in cases of anterior infarction. Shallow and narrow waves would not indicate significant damage, positive deflections would suggest normal electrical activity rather than necrosis, and completely absent Q waves would typically indicate the absence of a prior infarction which contradicts the question context. Thus, "deep and wide" is the defining criterion for significant Q waves in this scenario.