User Manual Part 1

TACHYARRHYTHMIA DETECTION
VENTRICULAR DETECTION
3-15
630 600 600 370 390 380 275 275 600 275 250 250
S S S S F F F F F F F F
240 240
F F
S S S S S S S F F F F F F F
240
F
F
VF Zone Rate = 200 min
-1
(bpm) = 300 ms
VT Zone Rate = 150 min
-1
(bpm) = 400 ms
S = Slow F = Fast
Intervals in ms
8 of 10 intervals are fast, VF window is satisfied.
7 of 10 intervals are fast, VF window not satisfied.
6 of 10 intervals are fast, VF window not satisfied.
8 of 10 intervals are fast, VT window is satisfied.
7 of 10 intervals are fast, VT window not satisfied.
6 of 10 intervals are fast, VT window not satisfied.
VF window
VT window
Figure 3-4. Interaction of ventricular detection windo w s, 2-zone configuration
Duration Parameter
The Duration parameter is a timer that measures the length of time in each
zone that a rhythm must be sustained before therapy is delivered.
A Duration timer begins when its respective zone’s detection window is
satisfied. The programmed Duration time is checked following every cardiac
cycle to determine if it has expired.
NOTE: Since the Duration timer is examined synchronously with a cardiac
cycle, the programmed Duration may be exceeded by up to one full cardiac
cycle.
• As long as the zone’s detection window remains satisfied, the Duration
timer continues to elapse. If the last detected interval is in the zone when
its Duration time expires, detection is considered met and therapy is
initiated (assuming no programmed detection enhancements inhibit therapy
delivery) (Figure 3-5 on page 3-16).
• If the last detected interval is not in the zone, therapy is not initiated. Each
subsequent interval will be checked until an interval is in the original zone,
or the window is no longer satisfied (Figure 3-6 on page 3-16).
- DRAFT -