User Manual

test is successful.
2. When the Atrial Autothreshold function is programmed to "Monitor," the programmed
atrial pacing amplitude value is preserved.
Programming constraint:
The Atrial Autothreshold function is not programmable when the basic rate is above:
― 85 ppm with an atrial autothreshold max rate at 120 ppm,
― 80 ppm with an atrial autothreshold max rate at 110 ppm,
― 70 ppm with an atrial autothreshold max rate at 100 ppm.
WARNING: Certain drugs can greatly increase the pacing threshold. In case the patient has
a complete AV block, the test is not launched and is considered not successful. The Atrial
Autothreshold function should be used with caution, properly adjusting the minimal atrial
amplitude.
PMT protection (for the DR model only)
Protection against Pacemaker-Mediated Tachycardia (PMT) can be provided for all patients
with retrograde ventriculoatrial conduction without reducing atrial sensing capability.
Description:
Since most PMTs are initiated by AV dissociations (PVCs) or by asynchronous to
synchronous switching (magnet mode, threshold test, noise sensing, and reassociation after
Fallback Mode Switching), the pacemaker automatically extends a post ventricular atrial
refractory period to 500 ms for one cycle following detection of any such event.
The pacemaker does not trigger an AV delay on a P wave likely to be retrograde, thus PMT
is prevented.
Other events such as isolated artifacts or loss of capture can induce PMTs. The pacemaker
can identify these PMTs by means of an algorithm based on the stability of the VP interval
(from ventricular paced beat to retrograde P wave). Once a PMT has been confirmed, the
pacemaker initiates a post-ventricular atrial refractory period of 500 ms in order to terminate
the PMT. Termination occurs within 12 cardiac cycles.
NOTE:AV delay is modified for 1 or 2 cardiac cycles.
Example: Palliative protection (permanently applicable). The pacemaker does
not trigger an AV delay on a P wave detected within 500 ms following an
asynchronous ventricular event.
Lead Polarity Switch
The Lead Polarity Switch feature measures lead impedances over the long-term operation
of the device and enables the device to switch bipolar pacing and sensing to unipolar when
bipolar lead integrity is in doubt. When a bipolar lead impedance is less than 200 Ω or more
than 3000 Ω, the lead could be considered defective. Lead impedance measurements are
performed every 6 hours. If 2 out of the last 4 measurements of a bipolar lead are out of
range, the Lead Polarity Switch operates.
15.7.5.
15.7.6.
15. FUNCTIONS AND PARAMETERS
50 ALIZEA – UA10414A