Philips MX400 - Printing The QT Waves; Recording The QT Waves; QT Alarms

6 ECG, Arrhythmia, ST and QT Monitoring
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To set the baseline,
•Select
Set Baseline and set the value.
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
baseline.
Printing The QT Waves
To start a printout,
•Select
Print QT.
Recording The QT Waves
To start a recording,
•Select
Record QT.
QT Alarms
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.
The
Cannot Analyze QT INOP and the -?- will be displayed when no QT measurement could be
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.
Additional Message Cause of Invalid QT Measurement
QT Startup QT monitoring was just turned on or has been reset
Asystole or Leads Off 1 Not all specified leads needed to perform QT analysis are
available, or
2 Asystole condition is detected
Too few N labeled beats Not enough valid QRS complexes to generate a QT measurement
Invalid Rhythm for QTc Not enough valid RR intervals to generate QT-HR, the averaged HR
used for QTc calculation
High QT-HR QT-HR exceeds the specified upper limit of 150 bpm (for adults) or
180 bpm (for neonates and pediatrics)
Small R Wave R-wave of the signal is too small
Small T Wave T-wave of the signal is too small
End of T not Detected End of the T-Wave cannot be accurately detected
QT out of Range QT measurement is outside the specified range of valid QT values
(200-800 msec)
QTc out of Range QTc measurement is outside the specified range of valid QTc values
(200-800 msec)
QTc Erratic QTc measurements are not stable