User Manual

NOTES:
The Rest AV delay and the Exercise AV delay are automatically programmed and calculated
when Dplus mode is selected.
If the basic rate is equal to 30 ppm, the effective AV delay may be shorter than the
programmed value.
If the basic rate is less than 60 ppm, the rest AV delay is used for all rates between the basic
rate and 60 ppm.
The effective AV delay following atrial pacing may be longer than the programmed AV delay
if an AVD Paced/Sensed Offset is programmed.
The effective AV delay following atrial sensing may be longer than the value programmed
(Wenckebach mode).
An AV delay of 30 ms is applied if atrial sensing occurs outside refractory periods in
Wenckebach response mode.
The AV delay can be shorter than the programmed AV delay if pacing is delivered at the end
of the committed period.
During periods of suspected atrial arrhythmia, an AV delay of 30 ms is applied if atrial
sensing occurs. An AV delay of less than or equal to 110 ms is used if there is atrial pacing
(the exercise AV delay is used if it is less than 110 ms).
If rest rate or rate hysteresis is programmed, the rest AV delay is applied for rates below the
basic rate.
The anti-PMT algorithm may modify the AV delay during the confirmation phase (see
"Protection from Retrograde P Waves" section).
AVD Paced/Sensed Offset (for the DR model only)
In DDD mode, the programmed value of the AVD Paced/Sensed Offset is added to the AV
delay after atrial pacing. The difference between AV and PV intervals compensates for the lag
between the atrial stimulus and atrial contraction. This helps to maintain a consistent interval
between ventricular and atrial contractions whether AV sequential or P synchronous pacing
occurs.
Programming requirement:
In Dplus mode, the AV delay plus the AVD paced/sensed offset between atrial and ventricular
pacing cannot exceed 350 ms. In the other pacing modes, the AV delay plus the AVD
paced/sensed offset between atrial and ventricular pacing cannot exceed 300 ms.
RATE RESPONSE
The Rate Response function makes it possible to adjust the pacing rate based on the patient's
physical activity.
Sensors used:
The pacemaker is equipped with two sensors that prevent rate increases due to artifact
through cross-checking of information:
1. Minute ventilation (MV): this is calculated based on the measurement of transthoracic
impedance by standard (unipolar or bipolar for the DR model, bipolar for the SR model)
intracardiac leads. It is used to obtain a physiological response proportional to the degree
of exertion during periods in which the patient is active.
2. An accelerometer (G), which measures changes in the patient’s anteroposterior
acceleration: a rapid response may thus be obtained at the start of exertion and the end
of exertion can be detected immediately.
15.4.4.
15.5.
15. FUNCTIONS AND PARAMETERS
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