User Manual Part 1

5-8
PACING THERAPIES
BASIC PARAMETERS
Pulse Width (ms)
Amplitude (V)
Figure 5-2. Pulse waveform
Amplitude
The pulse Amplitude, or voltage of the output pulse, is measured at the leading
edge of the output pulse (Figure 5-2 on page 5-8).
Amplitudes are independently programmable. The following considerations
are important:
• During temporary programming, the brady pacing mode may be
programmed to Off. In effect, this turns Amplitude off to monitor the
patient’s underlying rhythm.
• A minimum 2x voltage safety margin is recommended for each chamber
based on the capture thresholds, which should provide an adequate safety
margin and help preserve battery longevity.
• The energy delivered to the heart is directly proportional to the square
of the amplitude. In other words, doubling the amplitude quadruples
the energy delivered, which will decrease pulse generator longevity.
Programming to a lower Amplitude while maintaining an adequate safety
margin may increase battery longevity.
Sensitivity
The Sensitivity parameter allows the pulse generator to detect intrinsic cardiac
signals that exceed the programmed value.
All detection and timing decisions are based on the sensed cardiac cycle
length. These pulse generators use an automatic gain control circuit to
dynamically adjust the sensitivity.
- DRAFT -