User's Manual

89
Rate Adaptation

Thus, sensor information is available prior to the activation of the rate
adaptation, which can be used to evaluate the sensor response (see
also the "Sensor Histogram" and "Activity Chart" sections under
"Diagnostic Memory Functions").
Note: In the sensor simulation, you can only select
sensor threshold values that are greater than those
used in the permanent program.
Rate Fading – Rate Smoothing
In all atrial-controlled modes, controlled rate fading during a sudden
incident of bradycardia leads to a more favorable adjustment of the
pacemaker’s pacing rate to the patient’s intrinsic rate.
When controlled rate fading is enabled, the pacemaker calculates a
"backup rate" that is always active in the background. As soon as the
rate decreases, the pacemaker paces at the backup rate. The backup
rate follows with a certain delay of the intrinsic rate corresponding to
the programmable rate increase (1; 2; 4; 8 ppm/cycle) and the
programmable rate decrease (0.1; 0.2; 0.5; 1.0 ppm/cycle). These
settings determine the sensitivity of the rate fading.
Figure 23: Rate fading after a physiological rate increase