Philips HEARTSTART XLT M3500B - Manual (Page 84)

Demand Mode Versus Fixed Mode
8-2 Pacing
Demand Mode Versus Fixed Mode
The HeartStart XLT can deliver paced pulses in either demand or fixed mode.
In demand mode, the pacer only delivers paced pulses when the patient’s
heart rate is lower than the selected pacing rate.
In fixed mode, the pacer delivers paced pulses at the selected rate.
Monitoring During Pacing
Multifunction defib electrodes pads can not be used to monitor the ECG and
deliver paced pulses simultaneously. The HeartStart XLT always uses the 3-
or 5-lead ECG cable and monitoring electrodes as the source of ECG during
pacing.
In demand mode, ECG electrodes must be used, because the HeartStart XLT
uses the R-wave detection from this monitoring source to determine if a paced
pulse should be delivered.
In fixed mode, ECG electrodes may or may not be used; however, an ECG
will only be displayed if ECG monitoring electrodes are used.
WARNING Use demand mode pacing whenever possible. Use fixed mode pacing when motion
artifact or other ECG noise makes R-wave detection unreliable.
WARNING Heart rate displays and alarms function during pacing, but they can be unreliable.
Observe the patient closely while pacing. Do not rely on heart rate alarms or the
indicated heart rate as a measure of the patient’s perfusion status.