User Manual Part 2

4-4
TACHYARRHYTHMIA THERAPY
VENTRICULAR THERAPY
• If the arrhythmia is converted to a rate below the lowest programmed
threshold, the pulse generator continues monitoring until the end of the
episode is declared. When the episode ends, the pulse generator will again
use initial ventricular detection criteria for a new episode. When a new
episode is declared, the first prescribed therapy w ill be delivered again.
• If the arrhythmia is not converted and an arrhythmia is redetected in
the same ventricular zone, the next programmed therapy in that zone
is selected and delivered (Figure 4-2 on page 4-4), followed again by
redetection. If the arrhythmia persists in the same zone, the therapy will
progress in that zone.
• If an a rrhythmia crosses ven tricular zones (accelerates or d ecelerates)
following therapy delivery and is redetected in a higher or lower ventricular
zone, a therapy of equal or greater strength than the previously delivered
therapy is selecte d from the detected zone and delivered (Figure 4-3 on
page 4-5 through Figure 4-10 on page 4-8). For shock therapy, the pulse
generator determines which s hock to deliver prior to capacitor charging
based o n the detected rate threshold. If during capa citor charging, the
tachyarrhyth mia accelerates or decelerates from the initia l detected r a te,
the predetermined energy will still be delivered.
Redetection is performed after each therapy delivery to determine if further
therapy is required.
1
3 2 4 5
6 7
Zone ATP1 ATP2 QUICK
CONVERT ATP
Shock 1 Shock 2 Remaining Shocks
VF
VT
VT-1
On/Off
N/A
N/A
5 J
3 J
0.1 J
11 J
9 J
2 J
Burst Scan
Ramp Burst
max max max max max max
max max max max
max max max
Figure 4-2. Therapy delivery progression, arrhythmia remains in same zone as initially detected
After each redetection cycle, therapy delivery progresses in the direction
indicated by the circled numbers (Figure 4-3 on page 4-5 through Figure 4-10
on page 4-8).
• Upward sloping lines indicate acceleration of the arrhythmia to a higher
ventricular zone
• Downward s loping lines indicate deceleration into a lower ventricular zone
- DRAFT -