User Manual Part 1

4-12
TACHYA RRHYTHMIA THERAPY
ANTITACHYCARDIA PACING THERAPIES AND PARAMETERS
• The Maximum Number of Pulses parameter de termines th e g reatest
number of pulses used in an ATP burst and may be programmed
independently for each ATP scheme. After the maximum number of pulses
is reached in a burst, each additional burst remaining in the scheme
contains the programmed Maximum Number of Pulses. The parameter is
available only if the Pulse Increment is greater tha n zero.
Coupling
Interval
Redetect Redetect Redetect
Detection
Satisfied
Burst 1; Initial
pulse count at 3
Burst 2; Pulse count
incremented by 1
Burst 3; Pulse count
incremented by 1;
Maximum Number of
Pulses reached
Burst 4; (programmed
number); Pulse count
remaining at Maximum
Number of Pulses (5)
Number of Bursts = 4
Initial Pulse Count = 3
Pulse Increment = 1
Maximum Number of Pulses = 5
Figure 4-12. Interaction of Maximum Number of Pulses and Number of Bursts
Coupling Interval and Coupling Interval Decrement
The Coupling Interval controls the timing of the firstpulseinaburst. Itdefines
thetimebetweenthelastsensedeventthatfulfills the detection criteria and
delivery of the first pulse in a burst.
The Coupling Interval is programmed independent from the Burst Cycle Length.
This allows aggressive ramps and scans to be used without compromising
capture of the first pacing pulse in a burst. The Coupling Interval can be
programmed as any of the following:
• Adaptive, with timing specified as percentages of the computed average
heart rate
•Afixed interval, with timing specified in absolute time (ms) independent of
the measured average rate
When programmed as adaptive, the Coupling Interval adjusts to the patient’s
rhythmbasedonafour-cycleaverage(Figure4-13onpage4-13). The
Coupling Interval D ecrement may be programmed such that the Coupling
- DRAFT -