What does an elevated ST segment mean?

As a medical professional with expertise in cardiology, I can explain the significance of an elevated ST segment in an ECG reading. An elevated ST segment on an electrocardiogram (ECG) is a deviation from the normal isoelectric line that occurs during the interval between the end of the QRS complex and the beginning of the T wave. This interval represents the time between ventricular depolarization and repolarization. ST segment changes can be indicative of various cardiac conditions, but the most important cause of ST segment elevation is typically myocardial ischaemia or infarction, which is commonly known as a heart attack. In the context of an ECG, ST segment elevation is a specific pattern that can suggest the presence of an acute coronary syndrome, which includes unstable angina and myocardial infarction (heart attack). This pattern is often associated with a blockage in a coronary artery that is restricting blood flow to a part of the heart muscle. It's important to note that while ST segment elevation is a critical finding, it is not the only cause of this abnormality. Other conditions, such as electrolyte imbalances, can also cause ST segment changes. Therefore, a thorough medical evaluation is necessary to determine the underlying cause.

It represents the interval between ventricular depolarization and repolarization. The most important cause of ST segment abnormality (elevation or depression) is myocardial ischaemia or infarction.