If a lead is in INOP (the value is being measured but is invalid or unavailable because, for example, the
corresponding ECG electrode is off), the area formed by the remaining ST leads is left open.
If there is insufficient information (for example, there are less than three chest leads) for a second ST
map to be displayed, the currently available ST values are displayed in place of the second ST map.
In trend view, you can see up to four trended ST maps, and the current ST map, simultaneously. You
can configure the time interval between trended samples. The most recent map is shown in the same
color as the parameter itself. Past values change from white through dark gray. In the diagram below,
the time interval between trends is 12 seconds. The first trended sample is white and is 12 seconds old.
The second trended sample corresponds to the ST values 24 seconds ago and so forth. The ST values
on the diagrams show the current ST values.
If a lead is turned off, its axis is no longer shown. This has no impact on the presentation of trended
values that were recorded while the lead was still on. In the diagram below, lead V4 was switched off
20 seconds ago. The current ST values and the first trended value reflect this change in the lead setup.
All other maps are displayed the way in which they were recorded.
current ST values
5 ECG, Arrhythmia, ST and QT Monitoring