User Manual Part 2

7-2
PATIENT DIAGNOSTICS
THERAPY HISTORY
THERAPY HISTORY
The pulse generator automatically records detection and therapy information
for each detected episode. This data can be reviewed at various levels of
detail using the PRM.
History data storage includes the following information for each episode:
• Episode detail
• Electrograms with annotated markers
• Intervals
The data includes information from all active electrodes. The device
compresses the history data to store a maximum of 17 minutes of electrogram
data (13 minutes w ith Patient Triggered Monitor enabled). However, the
amount of time actually stored may vary based on the data being compressed
(e.g., noise on the EGM or an episode of VF).
The priority, maximum number, and minimum number of episodes to be stored
by the device for each episode type under normal conditions are specified
(Table 7-1 on page 7-3). The device stores up to the maximum number of
episodes for a specific episode type, unless the device memory is filled up first.
The minimum number of episodes for each episode type protects a few low
priority episodes from high priority episode s whe n devic e memory is full.
Once the device memory available for episode data is filled , the dev ice attem pts
to prioritize the types of stored episodes and overwrite the stored episodes
according to the followin g ru le s:
• If the dev ice memory is full, an d there are episode t y p es that have more
than the minimum number of episodes listed in the table, then the oldest
of the lowest priority episodes from these episode types will be deleted.
In this case, the low priority episodes are not deleted if their number of
episodes is less than the minimum number listed in the table.
• If the device memory is full, and there are no episode types that have more
than the minimum number of episodes listed in the table, then the oldest of
the lowest priority episodes of all episode types will be deleted.
• For non-commanded episodes, the episode type for VT-1, VT, and VF
episodes is determine d according to the z one Dura tio n that expires
first. If no zone Duration expires during an episode, the episode type
is nonsustained.
- DRAFT -