What does an elevated ST segment on an ECG indicate?

An elevated ST segment on an ECG is a significant finding often associated with acute myocardial infarction (AMI), commonly known as a heart attack. This elevation suggests that there is a disruption in the heart's electrical activity due to ischemia, where the heart muscle does not receive enough blood and oxygen. The ST segment represents the period between ventricular depolarization and repolarization. When it is elevated, it typically indicates that a portion of the heart is undergoing acute injury due to lack of perfusion, which is a hallmark of a myocardial infarction.

In contrast, a normal ST segment would indicate healthy heart function without ischemia. Cardiac arrhythmias can cause variations in the ECG but are not necessarily linked to specific elevations in the ST segment. Similarly, a heart murmur refers to abnormal sounds during the heartbeat and does not directly impact the ST segment on an ECG tracing. Thus, the presence of an elevated ST segment is specifically indicative of possible acute myocardial infarction, highlighting the severity of the underlying condition.