What characterizes a STEMI on an EKG?

A STEMI, or ST-Elevation Myocardial Infarction, is characterized on an EKG by specific changes that reflect the acute phase of a heart attack. The presence of significant Q waves is one of the key indicators. When myocardial tissue dies due to ischemia, it can lead to the development of pathological Q waves over time. These Q waves indicate that there has been significant damage to the heart muscle, reflecting a past infarction, although they may not appear in the immediate phase of a STEMI.

In the context of a STEMI, the most notable EKG finding is ST-segment elevation, which indicates ongoing ischemia and infarction but significant Q waves, which may develop as the condition progresses, are also a critical part of diagnosis. This understanding is essential for interpreting EKGs in the context of acute coronary syndromes.