Download DDI Prodigy Pocket Specifications

Medtronic Confidential
9879EN-13_9501043EN/CTC.qxd 5/10/99 11:29 Page 13-6
7 x 9 inches (178 mm x 229 mm)
13-6
Understanding Pacemaker Operations
Bipolar Sensing Polarity Confirmation
Before programming from unipolar to bipolar sensing, the programmer
verifies the presence of a functioning bipolar lead by testing impedance for
each lead at an Amplitude of 5.0 V and a Pulse Width of 1.0 ms if the
permanent settings are at or below this level. If permanent settings are
above these values, the measurement will be made at the permanent
settings. If lead impedance is between 200 Ω and 3000 Ω, a functional
bipolar lead is assumed to be present. If the impedance is outside this
range, a functional bipolar lead is not present; the programmer warns that
the test failed, and Sensing Polarity remains set to unipolar. This interlock
feature may be overridden and lead Sensing Polarity forced to bipolar.
WARNING: Do not override for an implanted lead. The override feature is
intended only as a means to program the pacemaker for bipolar polarity
before lead connection.
Determining Sensing Threshold(s) at Implant
At implant, a Medtronic Pacing System Analyzer (PSA) may be used to
determine sensing threshold values for all Prodigy models except the
Prodigy VDD model. Refer to the PSA manual for detailed instructions.
(Refer to the CapSure VDD Model 5032 lead technical manual for
information on determining sensitivity.)
Prior to lead connection, measure the sensing potentials in the unipolar and
(when appropriate) the bipolar configurations. When using a bipolar
system, an adequate intracardiac signal should be present in both
configurations to ensure proper sensing in either.
Verifying Sensing Threshold(s) at Follow-up
Intracardiac signal amplitudes decrease during the lead maturation process.
Medtronic programmers provide an automatic sensitivity test that allows
the follow-up clinician to verify a patient’s sensitivity setting(s). The
automatic test provides for atrial or ventricular monitoring. The test
provides the sensitivity setting just above and below the point at which
P or R waves are sensed.
For a detailed description of the test procedures, refer to “Determining a
Setting for Sensitivity” in Chapter 7.
196407001
Rev A
Refer to the “Reference man.” category in doc#163256 for Printing
Instructions.