6 ECG, Arrhythmia, and ST Monitoring Understanding the ST Display
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Understanding the ST Display
Your monitor screen may be configured to look slightly different from the illustrations.
ST Numerics Up to 12 ST numerics plus the
ST index can be displayed on the monitor
screen. They can be configured to show beside
the measurement numerics, beside the ECG
wave, or beside the ST snippet.
A positive ST value indicates ST segment
elevation; a negative value indicates depression.
ST numerics are displayed in the order in
which you select ST leads for analysis. If there
is additional space in the field assigned to ST numerics, the monitor will display extra numerics in the
order in which they appear in the Setup ST Analysis -> Setup ST Leads -> Choices
list. Any ST leads switched on for analysis that do not fit in the assigned numerics field are shown in
succession in place of the last ST numeric.
ST Index The ST index numeric (STindx) is the sum of the absolute values for the ST leads V2, V5,
aVF. Because it is based on absolute values, it is always a positive number. If you haven’t selected one of
the leads V2, V5, and aVF for ST analysis, the STindx numeric will display a question mark “?”.
♦ To switch the ST index numeric on or off for display, in the Setup ST Analysis menu,
select ST-Index to toggle between On and Off.
ST Snippets ST snippets show a one second wave segment for each measured ST lead. The most
recent snippet is drawn in the same color as the ECG wave, usually green, superimposed over the
stored baseline snippet, drawn in a different color. The comparison shows any deviation in the
measurement since the baseline snippet was stored, for example as a result of a procedure carried out on
the patient.
The information is updated once per minute.
If you do not see ST snippets on the Screen, select the Screen name in the Monitor Info Line and select
a Screen configured to show snippets from the pop-up list of available Screens.
ST Baseline Window The ST Baseline Window shows an ST snippet drawn on a grid. The current
ST numeric and the ST numeric stored with the baseline are shown, as well as the difference between
these two numerics.
A “?” in front of the difference numeric indicates that the ST measurement points were adjusted since
the baseline snippet was stored.
The Baseline Window opens with the ST pop-up keys Update Baseline, Record ST,
Change ST Lead, Adjust ST Points, ST Map and arrow keys for scrolling through the
available leads.
♦ To view the ST Baseline window, select any snippet on the Screen.
ST-II 1.2
ST-V 2.5
ST-aVR -3.0
Current heart rate
ST numerics
Current HR
alarm limits