Impulse Dymanics OPTIMIZER Smart System - Local Sense Refractory Periods in Active OVO-LS-CCM Mode; Remarks; Parameter Interaction

27
The leading edge of the first event detected within this window is used to trigger
CCM signal delivery. When an event is detected, the Local Sense Alert Window
is immediately closed. Any Local Sense events detected after the window closes
are considered to lie outside the Alert Window and lead to the LS Out of Alert
Status.
If a Local Sense event is detected outside the Alert Window, CCM signal delivery
is always inhibited.
9.8.2 Local Sense Refractory Periods in Active OVO-LS-CCM Mode
With the exception of events occurring during the Local Sense Refractory
Periods, any event detected through the LS channel is considered a valid Local
Sense event.
Local Sense Refractory Periods include:
• Pre V Refractory Period: Ends with the ventricular event. With the
OMNI Smart Programmer software, the duration can be set to values
between 0 ms and 55 ms, in 5 ms increments.
• Post V Refractory Period: Begins with the ventricular event. With the
OMNI Smart Programmer software, the duration can be set to values
between 0 ms and 39 ms, in 1 ms increments.
• Post LS Refractory Period: Begins with a valid LS event. With the
OMNI Smart Programmer software, the duration can be set to one of 56
possible values between 15 ms and 250 ms.
• Post CCM Refractory Period: Begins with the start of the CCM signal
train and ends with the end of the Right V Refractory Period.
9.8.3 Remarks
If the Pre- and Post-ventricular LS Refractory Periods are inside the Local Sense
Alert Window (i.e. if the Alert Start is negative and the sum of Alert Start and
Alert Width is longer than the Post-Ventricular Refractory Period), only Local
Sense events falling inside the Alert Window and outside the Ventricular LS
Refractory Periods will trigger CCM signal delivery.
If a Local Sense event is detected after the window closes and before CCM signal
train delivery commences, the new event is considered to be outside the Alert
Window and CCM signal delivery will be inhibited.
In Active ODO-LS-CCM mode, the Local Sense Alert Window cannot start prior
to the atrial event. Therefore, if the Alert Start occurs before the end of the post-
atrial refractory period (Alert Start is negative and the AV interval minus the
Post-Atrial Refractory Period is smaller than the absolute value of Alert Start), the
Local Sense Alert Window will start at the end of the Post-Atrial Refractory
Period.
9.8.4 Parameter Interaction
Local Sense signals are ignored during Local Sense refractory periods. Therefore,
the OMNI Smart Programmer software will not permit the Alert Window to start
or end inside the pre- and/or post-ventricular refractory period.