Medtronic PROTECTA XT DR D314DRG, Clinician Manual

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Figure 93. AV Conduction test method
Overdrive rate short interval
Overdrive rate shorter
interval
Loss of Capture
Capture
(Expected VS
from Test AP)
(Expected VS
from Backup AP)
Scheduled
VP
70 ms
AP AP
VS VS VP
Backup AP
Backup AP
Test
AP
Test AP
AP-VS
7.5.3.3 Adjusting atrial pacing outputs
If ACM is programmed to the Adaptive setting, the device automatically adjusts the Atrial
Amplitude based on the pacing threshold search results. After a successful pacing threshold
search, the device calculates a target amplitude by multiplying the programmed Atrial
Amplitude Safety Margin by the amplitude threshold measured at a pulse width of 0.4 ms.
The device calculation for the target amplitude is rounded up to the next programmable
amplitude setting. For information about target amplitudes and safety margins, refer to
Section 7.5.2.2.
Adjustments during the acute phase – The programmable acute phase corresponds to
the lead maturation period. During this time, adequate pacing output is ensured by
restricting output adjustments. The acute phase begins when implant detection is complete.
The nominal length of the acute phase is 120 days, but the Acute Phase Remaining
parameter can be reprogrammed to change the length of the acute phase.
During the acute phase, the lower limit for Atrial Amplitude is the last user-programmed
amplitude setting or 3.5 V, whichever value is higher. The Atrial Pulse Width is maintained
at the last highest setting programmed by the user or 0.4 ms, whichever value is higher.
Adjustments after the acute phase – The device applies the programmed Atrial
Amplitude Safety Margin to the target amplitude measured at a 0.4 ms pulse width to
Medtronic PROTECTA™ XT DR D314DRG
Clinician Manual 243