In the limb leads, the ST segment is normally isoelectric, or less than 1 mm above or below the isoelectric line.

Question

Quizplus · Accepted Answer

The normal ST segment begins at the isoelectric line, extends from the end of the S wave, and curves gradually upward to the beginning of the T wave. In the limb leads, the normal ST segment is isoelectric (flat) but may normally be slightly elevated or depressed (usually by less than 1 mm).

In the Limb Leads, the ST Segment Is Normally Isoelectric