ST segment


In electrocardiography, the ST segment connects the QRS complex and the T wave and has a duration of 0.005 to 0.150 sec.
It starts at the J point and ends at the beginning of the T wave. However, since it is usually difficult to determine exactly where the ST segment ends and the T wave begins, the relationship between the ST segment and T wave should be examined together. The typical ST segment duration is usually around 0.08 sec. It should be essentially level with the PR and TP segments.
The ST segment represents the isoelectric period when the ventricles are in between depolarization and repolarization.

Interpretation

In fetal electrocardiography, ST waveform analysis is used to get an indication of increasing levels of fetal base deficit.