ST Segment — ECG/EKG Terminology

Definition: The interval between ventricular depolarization and repolarization. Elevation or depression can indicate ischemia or infarction.

Key Facts

• Segment between QRS end and T-wave onset representing early ventricular repolarization.
• Normally near the isoelectric baseline in most leads.
• Elevation or depression patterns can reflect ischemia, infarction, or pericarditis.

ECG Connection: ST trend analysis is central to ACS surveillance on telemetry and 12-lead review.

Why It Matters: Prompt recognition of dynamic ST changes supports urgent coronary evaluation.