BIOTRONIK Evia DR, Техническое руководство

Страница: 146 / 183

138 Evia Technical Manual
In addition to the manual ventricular threshold test, the threshold
test can be performed automatically, requiring no user
interaction. The automatic threshold test uses the VCC function
to determine the threshold. Once the threshold is determined,
VCC is deactivated if the feature is not programmed ON in the
permanent program.
12.4 P/R Measurement
The pulse generators provide a P-/R-wave test for measuring the
amplitude of intrinsic events during follow-up examination. The
test determines the minimum, mean and maximum amplitude
values over a programmable period of time. In addition, these
values may be printed out.
To permit evaluation of the sensing function, the pacing rate
must be lower than the patient's intrinsic rate. In demand
pacing, the proper sensing function can be recognized if the
interval between intrinsic events and the following pacing pulse
equals the basic interval (if no Hysteresis is programmed).
For evaluation of the sensing function, the pulse generator
features an intracardiac electrogram (IEGM) with marker signals
to indicate sensed and paced events. In addition, triggered
pacing modes can be selected, which synchronously to the
detection of an intrinsic event, emit a pacing pulse and mark the
sensed event and its timing on the ECG.
Especially with unipolar sensing functions, the selected
sensitivity level should be checked for possible interference from
skeletal myopotentials. If oversensing is observed, the
programming of a lower sensitivity (higher value), or bipolar
sensing function, if the implanted lead is bipolar, should be
evaluated.