User's Manual

90
Rate Adaptation
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After four consecutive A
S
, the target rate for the backup rate is
calculated from the current atrial sensing rate minus 10 ppm. AES and
A
P
set the target rate to the value of the basic/sensor rate.
Figure 24: Controlled rate fading after a sudden incident of tachycardia
If atrial tachycardia occur suddenly triggering a mode switch, the
target rate is set to either the sensor or basic rate. The current pacing
rate in the ventricle is determined from the current value of the backup
rate prior to the mode switching event.
If the pacing rate reaches the intrinsic rate during the rate drop, at
least four consecutive intrinsic cycles above the pacing rate are
required before the pacing rate is once again adapted to the last
intrinsic event.
Controlled rate smoothing is thereby continued during intermittent
sense events.