Which feature is indicative of a STEMI on an ECG?

ST-segment elevation in two contiguous leads is a key indicator of ST-Elevation Myocardial Infarction (STEMI) on an ECG. In STEMI, there is a complete blockage of coronary blood flow, leading to significant myocardial injury. This condition is evidenced by the elevation in the ST segment on the ECG, which reflects the acute phase of myocardial injury.

The presence of ST-segment elevation specifically in contiguous leads indicates the area of the heart that is affected by ischemia. Contiguous leads refer to those that view the same anatomical region of the heart, typically across a specific wall or zone. The requirement for elevation in two contiguous leads helps to rule out other causes of ST-segment elevation, ensuring that the finding is indicative of a myocardial infarction rather than a transient or benign condition.

In contrast to this correct answer, ST-segment depression in multiple leads can indicate ischemia but does not pinpoint a STEMI. Q waves in lead V1 might indicate a prior myocardial infarction, but on their own, they do not confirm a current STEMI event. Lastly, normal sinus rhythm signifies that the heart is functioning normally electrically, which would not be consistent with the elevated biomarkers of a STEMI. Thus, ST-segment