Medtronic PROTECTA XT DR D314DRG, Руководство для клиницистов

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Figure 170. Operation of Onset during a rapidly accelerating ventricular rate
Marker Channel
V-V interval
VT event count
VT interval
Onset calculation
ECG
9
2
0
9
2
0
3
6
0
3
5
0
1 2 3 4
3
5
0
3
5
0
3
5
0
920
920
100%
920
920
100%
920
920
100%
780
920
85%
638
920
69%
A
S
V
S
A
S
V
S
A
S
V
S
A
R
T
S
A
R
T
S
A
R
T
S
A
R
T
S
V
S
A
S
V
S
200 ms
9
2
0
920
920
100%
1 The ventricular rate is slow and steady.
2 The ventricular rate increases suddenly, with the first interval occurring in the VT detection zone.
However, because the average ventricular interval is 85% of the average of the previous 4
intervals (slower than the programmed Onset Percent of 81%), this interval is not classified as
a VT event.
3 The average ventricular interval is now 69% of the average of the previous 4 intervals (faster
than the programmed Onset Percent of 81%), so this interval is classified as a VT event.
8.5.2.1 VT Monitor events and the Onset feature
The Onset feature applies to both VT detection and VT monitoring.
8.5.2.2 Ensuring appropriate detection of VT and VF events
Continuing arrhythmia episodes – The Onset feature does not affect redetection of
ventricular tachyarrhythmias. If a VT, FVT, or VF episode is detected, the Onset feature is
suspended until the episode is terminated.
VF detection – The Onset feature does not affect VF detection. The Onset feature can
prevent sensed ventricular events in the VT detection zone from being classified as VT
events, and therefore it affects VT detection, FVT via VT detection, and Combined Count
detection.
Medtronic PROTECTA™ XT DR D314DRG
Clinician Manual 337