BIOTRONIK Evia HF, Техническое руководство, Страница: 28 / 138

Chapter 5 Programmable Parameters
Evia HF / HF-T Technical Manual
PAGE 20
Hysteresis rate
B asic rate
Paced event
17
8
17
9
18
0
Scan Hysteresis programmed to 5 cycles
1 2 3 4
Hysteresis rate
B asic rate
Paced event
17
8
17
9
18
0
Scan Hysteresis programmed to 5 cycles
Sensed event
Hysteresis rate
B asic rate
Paced event
17
8
17
9
18
0
Scan Hysteresis programmed to 5 cycles
1 2 3 4
Hysteresis rate
B asic rate
Paced event
17
8
17
9
18
0
Scan Hysteresis programmed to 5 cycles
Sensed event
Figure 5: Repetitive Hysteresis
In the left portion of Figure 5 , pacing occurs at the hysteresis rate for the programmed number of
five cycles. Because there is no return of the intrinsic rhythm, the device restores pacing at the
programmed/sensor rate. The right side of Figure 5 shows a return of intrinsic activity after two paced
events at the hysteresis rate.
Once the intrinsic rhythm returns, the repetitive hysteresis count begins again. If the intrinsic rhythm
falls to the hysteresis rate before the 180 count has been met, the device uses the standard rate
hysteresis.
Repetitive hysteresis has been incorporated to promote spontaneous cardiac rhythm and may reduce
pulse generator energy consumption.
NOTE:
Repetitive Hysteresis can be used during night mode but it will not take the rate below the programmed
night rate.
Repetitive Hysteresis is only available when Hysteresis is selected on.
There is one Standard Hysteresis interval which occurs before the programmable number of Repetitive
Hysteresis occur.
5.2.5 Night Mode
Night rate is designed to reduce the pacing rate to emulate the decreased metabolic needs during
sleep. When Night Rate is active, the pacing rate automatically decreases during the programmed
hours. The Night Rate is programmable from 30 to 200 bpm or OFF.
Night rate can be programmed as low as 30 bpm EXCEPT when Ventricular Capture Control is
programmed ON in the Evia HF / HF-T if Bi-V pacing is turned OFF. When Ventricular Capture Control
is enabled, the lowest rate Night rate can be programmed is 45 bpm. This is because Ventricular
Capture Control requires a “working margin” of 15 bpm for AV modulation during capture testing. These
conflicts will appear in blue, as seen in Figure 6 .