What may the presence of "Q waves" on an EKG signify?

The presence of Q waves on an EKG may signify a previous myocardial infarction. Q waves are indicative of necrosis of the myocardial tissue, which occurs when there is a significant loss of blood supply to that area, typically due to a blockage in the coronary arteries. When an infarction occurs, it often results in dead heart tissue that will manifest as Q waves on an EKG tracing, particularly in leads that correspond to the area of the heart that was affected.

This finding is usually contrasted with ongoing ischemia, where Q waves may not yet be present, as ischemia relates to reduced blood flow that may still be reversible if addressed. Normal heart function would not typically show Q waves, as they are an abnormal finding. Increased atrial pressure is also unrelated to Q waves, as it would more likely manifest as changes in P waves or other signs associated with atrial enlargement or congestion issues. Understanding the role of Q waves in diagnosing previous heart events is crucial for accurately interpreting EKG results.