Changing The View To A Single Wave Set
To view one set of waves in a larger scale, you can cycle through the different views,
Setting The QT Baseline
In order to quantify changes in the QTc value, you can set a QTc baseline. For example to assess the
effect of medication on the QT interval you can set the current value as the baseline before you begin
medication. This baseline will then be used to calculate the ΔQTc value.
To set the baseline,
If no baseline has been set for this patient, the first five minute value after the start of monitoring is
automatically set as baseline. If you set a new baseline the previous baseline is discarded. As the ΔQTc
alarm is based on the difference between the baseline and the current value, setting an inappropriate
new baseline may prevent a ΔQTc alarm from being generated. Discharging a patient clears the
Printing The QT Waves
To start a printout,
Recording The QT Waves
To start a recording,
There are two QT alarms, QTc high limit alarm and ΔQTc high alarm. The QTc high limit alarm is
generated when the QTc value exceeds the set limit for more than 5 minutes. The ΔQTc alarm is
generated when the difference between the current value and the baseline value exceeds the set limit
for more than 5 minutes.
Cannot Analyze QT
calculated for 10 minutes. Up to this time the previous valid value will be displayed. The following
additional messages on the cause of the invalid measurements may also be displayed.
Asystole or Leads Off
Too few N labeled beats
view to see the set of current waves.
view to see the set of baseline waves.
view to return to the combined view with current and baseline waves.
and set the value.
INOP and the -?- will be displayed when no QT measurement could be
Cause of Invalid QT Measurement
QT monitoring was just turned on or has been reset
Not enough valid QRS complexes to generate a QT measurement
6 ECG, Arrhythmia, ST and QT Monitoring
Not all specified leads needed to perform QT analysis are
Asystole condition is detected