ECG Basics


ST Segment

The ST segment is the portion of the ECG from the end of the QRS complex to the beginning of the T wave. The ST segment normally remains isoelectric, thus ST segment depression or ST segment elevation can indicate cardiac pathology.

The ST segment is scrutinized on the ECG for the detection of myocardial ischemia. This can be done in the setting of either exercise or pharmacologic stress testing.

Abnormal ST segments are reviewed based on the causes outlined in the relevant ECG Reviews and Criteria sections and include anterior, posterior and inferior myocardial infarctions, left ventricular hypertrophy, pericarditis and Brugada syndrome.