User Manual

Adaptation to nocturnal AV blocks:
The device switches to DDD(R) mode and remains in DDD(R) mode when it has:
― 45 episodes of AV block or more during the last 24 hours
― 15 episodes of AV block or more per 24 hours during 3 consecutive days
― 50% DDD(R) pacing or more during one hour.
In these cases the automatic switch to AAI(R) following every 100 ventricular paced cycles is
suspended. It remains in DDD(R) mode until 8:00 am the next morning.
Adaptation to conduction disorders during exercise:
When an AV block occurs during an exercise, after 3 switches the device remains in DDD(R)
mode until the end of the exercise in order to avoid patient symptoms during exercise.
NOTE:
Physicians may alternatively program AAI(R), or DDD(R) with a long AV delay, to minimize
ventricular pacing. However, AAI(R) will not provide any ventricular pacing in case of AV
block. DDD(R) mode will always provide ventricular pacing after every normal atrial beat at
the programmed AV delay; consequently in the circumstances listed above, DDD(R) will
provide more ventricular pacing than SafeR(R).
Dplus mode
The Dplus pacing mode preserves spontaneous atrioventricular conduction.
Operation:
An AV monitoring period allows for small variations in the spontaneous atrioventricular delay.
If no ventricular sensing occurs during that period, the pacemaker converts to DDD mode
until atrioventricular conductions return to normal. In DDD mode, the pacemaker uses the AV
delays calculated from the averaged PR intervals.
The Dplus-R mode is a Dplus mode with Rate Response.
The Dplus/DDIR mode activates a switch from Dplus to DDIR mode when the pacemaker
enters Fallback Mode Switching. Rate responsive pacing is only functional when the patient
is in Fallback Mode Switching. The physical activity used during the Fallback Mode Switching
phase is equal to the programmed parameter.
Rate acceleration
The Acceleration function is used to suppress the cardiac pause and to reduce the
vasodepressive response that accompanies it.
Indication:
Acceleration should be used only for patients presenting sinocarotid hypersensitivity with
vasodepressive response.
Operation:
1. The pacing rate is gradually increased (up to the programmed percentage) when an
abrupt drop in sinus rate is sensed.
2. The rate is then gradually reduced in accordance with the principle of rate smoothing.
15.6.2.
15.6.3.
15. FUNCTIONS AND PARAMETERS
44 ALIZEA – UA10414A