User Manual Part 1

TACHYARRHYTHMIA THERAPY
VENTRICULAR THERAPY
4-3
Ventricular Therapy Selection
The pulse generator determines which ventricular therapy to deliver based
on the following rules:
• Each successive therapy delivery must be greater than or equal to the
strength of the previous therapy in a ventricular episode. Whenever a
ventricular shock therapy has been delivered, no further ventricular ATP
therapy is allowed in that episode since ATP therapy is of lower strength
than shock therapy. Each subsequent ventricular shock delivery must be of
equal or greater strength regardless of ventricular zone changes during a
ventricular episode.
• Each ventricular AT P scheme (which ma y consist of multiple bursts) can
only be delivered once during a ventricular episode.
• Up to 8 shocks may be delivered in a ventricular episode. The first 2 shocks
are programmable. The following maximum-energy, non-programmable
shocks are available in each zone:
– VT-1 zone: 3 maximum-energy shocks
– VT zone: 4 maximum-energy shocks
– VF zone: 6 maximum-energy shocks
NOTE: In the e vent a shock is diverted with the DIVERT THERAPY
programmer command, by magnet application or due to a Diverted-Reconfirm,
the diverted shock is not counted as one of the available shocks for that
tachyarrhythmia episode. Also, commanded therapies and STAT SHOCK are
not counted as one of the available shocks for an episode and do not affect
subsequent therapy selection.
Based on initial ventricular detection criteria, the pulse generator selects the
first prescribed therapy in the ventricular zone in which the tachyarrhythmia
is detected (i.e., detection is m et; see "Ventricular Detection" on page 3-6).
After delivering the selected therapy, the pulse generator begins redetection to
determine whether the arrhythmia has been converted.
• 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. W hen a new
episode is declared, the first prescribed therapy will be delivered again.
- DRAFT -