5 ECG, Arrhythmia, ST and QT Monitoring
optimizes ECG signal quality. This is important for arrhythmia analysis. The monitor continuously
filters the ECG signal to remove baseline wander, muscle artifact, and signal irregularities. Also, if
the Patient Paced status is set to Yes, pace pulses are filtered out to avoid processing them as QRS
detects beats, for example, QRS complexes, identifying them for further analysis.
measures signal features such as R-wave height, width, and timing.
creates beat templates, and classifies and labels beats to aid in rhythm analysis and alarm detection.
examines the ECG signal for ventricular fibrillation, asystole, and noise.
Your monitor has either the basic or the enhanced arrhythmia option. Both options provide rhythm
and ectopic status messages and beat labeling. The number of rhythms being classified, events being
detected, and alarms generated differs according to the option. The alarms available with the different
options are listed in the section "ECG and Arrhythmia Alarm Overview" on page 124, the rhythm and
ectopic messages detected are listed in "Arrhythmia Status Messages" on page 130.
Where Can I Find More Information?
See the Application Notes on ST and Arrhythmia supplied on your documentation DVD for detailed
information on the arrhythmia algorithm and its clinical application.
Switching Arrhythmia Analysis On and Off
Be aware that when arrhythmia analysis is switched off,
only the HR-related alarms are detected (the asystole alarm, the ventricular fibrillation/
tachycardia alarm, the extreme tachycardia and extreme bradycardia alarms, the high heart rate
and low heart rate alarms)
HR High and HR Low alarms behave like normal yellow alarms, no timeout periods are active.
Choosing an ECG Lead for Arrhythmia Monitoring
It is important to select a suitable lead for arrhythmia monitoring.
Guidelines for non-paced patients are:
QRS complex should be tall and narrow (recommended amplitude > 0.5 mV)
R-Wave should be above or below the baseline (but not bi-phasic)
T-wave should be smaller than 1/3 R-wave height
the P-wave should be smaller than 1/5 R-wave height.
For paced patients, in addition to the above, the pace pulse should be:
not wider than the normal QRS
the QRS complexes should be at least twice the height of pace pulses
large enough to be detected, with no re-polarization.
pop-up key which appears at the bottom of the screen.
to toggle between
appears beside the ECG wave, if configured to do so