Specifications

7 x 9 inches (178 mm x 229 mm)
Medtronic Confidential
Refer to the “Reference man.” category in doc#163256 for Printing
Instructions.
196407001 Rev A
Threshold Test Options
The first two steps in the procedure for conducting a threshold test are to
select a test chamber/mode option (when applicable) and to select the
desired threshold test type. The buttons for these options appear below the
waveform display on the Threshold Test Start screen.
Chamber/Mode Selection
The chamber/mode options that appear depend on the present permanent
pacing mode.
If the permanent pacing mode is DDD or DDDR, you
can choose to run the threshold test in the atrium or
the ventricle using either DDD or AAI/VVI as the
test mode.
If the permanent mode is a dual chamber mode other
than DDD or DDDR, you can choose the chamber,
but the test mode will be limited to AAI/VVI.
If the permanent mode is a single chamber mode, the
test chamber and mode will be fixed according to
chamber being paced.
Test Type Selection
Test type buttons let you select one of four different threshold tests or the
Inhibit function.
[
STRENGTH
-
DURATION CURVE THRE-
SHOLDS
] — Select this test to use auto-
matic, step-by-step reduction of output
energy to measure stimulation thresholds
for both amplitude and pulse width. This
test graphically displays the results as a
computed strength-duration curve. The
results screen lets you select the desired
voltage safety margin and directly pro-
gram permanent amplitude and pulse
width values.
[
AUTO AMPL THRESHOLD
]
— Select this test to measure the patient’s ampli-
tude threshold. Pressing and holding the [
PROGRAM
] button results in
automatic, step-by-step reduction of the pacing pulse amplitude.
[
AUTO PW THRESHOLD
]
— Select this test to measure the patient’s pulse
width threshold. Pressing and holding the [
PROGRAM
] button results in
automatic, step-by-step reduction of the pacing pulse width.
Determining and Evaluating Parameter Settings 7-3