What does the presence of Q waves in the lateral leads (I and AVL) signify?

What does the presence of Q waves in the lateral leads (I and AVL) signify?

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

Answer: (C)

The presence of Q waves in the lateral leads, such as I and aVL, is indicative of a lateral myocardial infarction. When Q waves appear in these leads, it suggests that there has been a significant necrosis of the myocardium, specifically affecting the lateral wall of the heart, which is supplied by the left circumflex artery or the diagonal branches of the left anterior descending artery.

In the context of EKG interpretation, Q waves represent a loss of electrical activity due to dead myocardial tissue following an infarction. The location of these Q waves is crucial in determining the area of infarction. In this case, observing Q waves in leads I and aVL directly correlates to damage in the lateral wall of the left ventricle. Thus, recognizing these changes on the EKG allows clinicians to accurately identify the affected regions of the heart and tailor appropriate management strategies.

Understanding the specific lead changes is vital for effective diagnosis and treatment, making it imperative for those interpreting EKGs to be aware of the significance of Q wave presence in particular leads.