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ECG tutorial: ST and T wave changes

Jordan M Prutkin, MD, MHS, FHRS
Section Editor
Ary L Goldberger, MD
Deputy Editor
Gordon M Saperia, MD, FACC


ST and T wave changes may represent cardiac pathology or be a normal variant. Interpretation of the findings, therefore, depends on the clinical context and presence of similar findings on prior electrocardiograms.


Nonspecific ST-T wave changes are very common and may be seen in any lead of the electrocardiogram. The changes may be seen in all or most of the leads (diffuse changes), or they may be present contiguous leads, such as the inferior, lateral, or anterior leads.

The types of abnormalities are varied and include subtle straightening of the ST segment, actual ST segment depression or elevation, flattening of the T wave, biphasic T waves, or T wave inversion (waveform 1). In the absence of a clinical history or symptoms, T wave abnormalities and flattened and depressed ST segment changes are nonspecific. Causes of these changes include:

Functional and physiologic variants (eg, post-prandial)

Electrolyte abnormalities

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Literature review current through: Nov 2017. | This topic last updated: Aug 18, 2016.
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