As a medical professional with expertise in cardiology, I can explain that the ST segment on an electrocardiogram (ECG) represents the period of time between the end of the ventricular depolarization and the beginning of the ventricular repolarization. This is a critical phase in the cardiac cycle where the ventricles are in a state of relative electrical inactivity before they begin to repolarize in preparation for the next heartbeat. Abnormalities in the ST segment, such as elevation or depression, can be indicative of various cardiac conditions. The most common and significant cause of ST segment changes is myocardial ischemia or infarction, which is damage to the heart muscle due to insufficient blood supply. This can be a sign of a heart attack or other serious heart conditions. Other factors can also affect the ST segment, including electrolyte imbalances, certain medications, and systemic illnesses. It's important for healthcare providers to interpret ST segment changes in the context of the patient's overall clinical presentation and other diagnostic information. read more >>

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.read more >>