The ST segment of the electrocardiogram is the isoelectric (flat) section between the S and T waves. During the period represented by the ST segment, the myocardial cells in heart are recovering from previous contraction (repolarization). During hypoxia, the energy balance within the myocardial cells is disrupted and the morphology of the ST segment changes causing an apparent elevation or depression of the isoelectric form. Consequently, changes in the ST segment are marker for myocardial ischaemia or infarction.
ST analysis is an important diagnostic tool for monitoring adult, adolescent and fetal electrocardiograms.
The STAN S41 is the only CTG offering fetal ST monitoring as a fully integrated diagnostic tool. The intended purpose of the ST analysis functionality is to reduce the incidence of fetal acidaemia and hypoxia by identifying these earlier and with greater sensitivity than would normally be possible with CTG alone.