Medtronic PROTECTA XT DR D314DRG, Clinician Manual

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Figure 172. Operation of Stability during atrial fibrillation
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V-V interval
VT event count
VT interval
ECG
Marker Channel
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1 Atrial fibrillation starts and is conducted into the ventricle at a rapid rate.
2 After 3 VT events, the device applies the Stability feature. Because the 360 ms interval differs
from the 290 ms interval by more than the programmed Stability interval (50 ms, in this case),
the device resets the VT event count.
8.6.2.1 Stability criterion for VT Monitor events
The VT Monitor zone has a non-programmable stability criterion that can reset the VT
Monitor event count, but does so independently from the VT event count. The VT Monitor
event count must be at least 3 before this stability criterion is applied to events in the VT
Monitor zone. Note that no data is recorded for this operation.
8.6.3 Programming considerations for the Stability feature
Stability interval – A small Stability value may not allow for normal VT interval variation
and may decrease the sensitivity of the device to detect ventricular tachycardia.
8.6.4 Programming the Stability feature
Select Parameters icon
⇒ Detection (V.)…
▷ Stability
Medtronic PROTECTA™ XT DR D314DRG
Clinician Manual 341