Impulse Dymanics OPTIMIZER Smart System - CCM Triggering Based on Local-Sense Events; Local Sense Alert Window

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9.8 CCM Triggering Based on Local-Sense Events
Delivery of CCM signal trains is synchronized with the intrinsic myocardial electrical
activity in the vicinity of the Local Sense (LS) electrode. The LS channel is configured to
sense parameters that characterize the activity of a small, local (near the electrode) part of
the heart. In response to the sensed activity, the OPTIMIZER Smart IPG evaluates the
myocardial electrical signal to determine whether it meets the criteria defined by the set
of LS parameter values programmed into the device. If the criteria are met, then the
device delivers the CCM stimulus. The timing of the signal detected through the LS
channel within a cardiac cycle, especially with regard to the R wave, is the main criterion
for the OPTIMIZER Smart IPG to classify the cycle as normal or abnormal. CCM signals
are not delivered during cycles classified as abnormal.
Provided that the CCM signal delivery is not prohibited by detecting a Local Sense event
inconsistent with the Alert Window, the OPTIMIZER Smart IPG may deliver CCM
pulses to thousands of heart beats over the course of a day. For example, it may deliver
CCM to several thousand beats out of 50,000 consecutive beats.
9.8.1 Local Sense Alert Window
When the internal logic of the device detects ventricular events corresponding to
cardiac cycles not classified as abnormal because of noise, atrial tachycardia, or
suspected PVCs, it will open a Local Sense Alert Window. The Alert Window
can be inside the AV interval, inside the VA interval, or partially inside the AV
and partially inside the VA interval.
The first event detected within the window serves as a trigger for CCM signal
delivery.
Valid Local Sense events detected outside the Alert Window are considered to be
PVCs and inhibit CCM signal delivery for a programmable number of cycles.
Inhibiting Local Sense events can be detected even between a triggering Local
Sense event and the start of the corresponding CCM signal, which in this case will
not be delivered.
The Local Sense Alert Window is the time interval during which the leading-edge
of valid LS events is used to trigger CCM signal delivery.
The position in time of this window is determined by two programmable
parameters:
• Alert Start: Begins with the right ventricular event. Using the OMNI
Smart Programmer software, Alert Start can be set to values between
-100 ms and 100 ms, in 2 ms increments. Please note that the Alert
Window starts inside the AV interval if this value is negative.
• Alert Width: Equivalent to the duration of the Alert Window. Using the
OMNI Smart Programmer software, Alert Width can be set to values
between 1 ms and 40 ms, in 1 ms increments. If the sum of Alert Start
and Alert Width is negative, the Alert Window ends inside the AV
interval.
Note: When the OPTIMIZER Smart IPG is in Active OVO-LS-CCM
mode, the maximum allowable setting for this parameter is 30 ms.