User Manual Part 1

3-16
TACHYARRHYTHMIA DETECTION
VENTRICULAR DETECTION
VT detection window is no longer satisfied; fewer
than 6 of 10 intervals are classified as fast.
VT window satisfied.
VT Duration starts.
VT Duration resets to zero. VT Duration will start
again when the window becomes resatisfied.
Need 8 of 10 intervals classified as fast to restart VT Duration. VT Duration 1-30 seconds VT detected
Right ventricle
Duration resets when during the Duration period the window is no longer satisfied.
Figure 3-7. Ventricular Duration reset
A Duration is programmed for each ventricular zone. Different values are
available depending on the configuration programmed (Table 3-5 on page 3-16).
The Duration programmed in lower ventricular rate zones must be greater than
or equal to higher ventricular zones. Longer Durations may be used to prevent
the device from initiating treatment of non-sustained arrhythmias.
Table 3-5. Duration programmable ranges by ventricular zone and configuration
Configuration
VT-1 Zone
a
VT Zone
a
VF Zone
b
1 Zone
–– ––
1–15 seconds
2 Zones
––
1–30 seconds 1–15 seconds
3 Zones 1–60 seconds 1–30 seconds 1–15 seco nds
a. The maximum redetect duration for the VT-1 and VT Zones is 15 seconds.
b. In the VF Zone, the redetect and post-shock duration is fixed at 1 second.
Duration in a Multi-zone Configuration
Duration timers run independently of each other within their respective
ventricular zones.
• If the arrhythmia is detected in the highest zone, that zone’s Duration timer
takes precedence over the lower zones’ timers; the lower zones’ Duration
timers continue to elapse but are ignored while the higher zone’s Duration
timer runs.
• If the higher zone’s Duration expires and detection is met, therapy for that
zone will be initiated regardless of whether the lower zones’ Duration
timers have expired.
- DRAFT -