User Manual

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104 Lumax Technical Manual
At the programmed start time (Begin of Night), the rate gradually
adapts to the night rate. When the internal clock reaches the
programmed end time (End of Night), the pacing rate gradually
changes to the programmed basic rate. The rate changes at the
same rate as the Sensor Gain decrease and increase
parameters.
NOTE:
The Night Mode time is based on the programmer clock.
Therefore, the programmer time should be checked prior to
device programming. If a patient travels across different time
zones, the Night Mode time may require adjustment.
2.9.4 Rate Hysteresis
The ability to decrease the effective lower rate through
Hysteresis is intended to preserve a spontaneous rhythm. The
pulse generator operates by waiting for a sensed event throughout
the effective lower rate interval (Hysteresis interval). If no sensed
event occurs, a pacing pulse is emitted following the Hysteresis
interval.
Hysteresis can be programmed OFF or to values as low as
-90 bpm in Lumax 300/340 & 500/540 models (-65 bpm in the
Lumax 600/640 & 700/740 models) of the basic rate. Hysteresis
is initiated by a sensed event. The resulting Hysteresis rate is
always less than the lower rate. The Hysteresis rate can only be
programmed to provide a basic rate that is 30 bpm or greater.
NOTES:
If rate adaptation is active, the Hysteresis rate is based on the
current sensor-indicated rate and the value of the
programmable parameter.
If Hysteresis is used in the DDI mode, the AV delay must be
programmed shorter than the spontaneous AV conduction
time. Otherwise, stimulation in the absence of spontaneous
activity occurs at the hysteresis rate instead of the lower rate.