User's Manual

4. Program the pulse generator appropriately if a lead port(s) is not used.
5. Program the pulse generator to desired parameters appropriate for the patient for conversion testing.
CAUTION: To prevent inappropriate shocks, ensure that the pulse generator ’s Tachy Mode is programmed to
Off when not in use and before handling the device. For tachyarrhythmia detection and therapy, verify that the
Tachy Mode is programmed to Monitor + Therapy.
Step I: Test for Ability to Convert Ventricular Fibrillation and Induci ble Arrhythmias
After obtaining acceptable signals from the implanted leads, the physician may choose to perform VT and VF
conversion testing to determine (1) if the configuration and position of the implanted leads are appropriate
for the patient and (2) if the pulse generator’s programmed shock energy or maximum-shock energy will
be sufficient to convert arrhythmias reliably and (3) if AGC and RhythmMatch Threshold are programmed
appropriately to detect VF/VT. A conversion test consists of inducing the arrhythmia and then attempting to
convert the arrhythmia with a preselected energy level.
Demonstrating conversion of ventricular fibrillation is suggested before implanting a pulse generator because a
shock delivered during ventricular tachycardia has the potential to accelerate the arrhythmia. Intraoperative
testing may be minimized by performing only VF testing at time of implant and performing VT testing
post-operatively in the electrophysiology lab prior to the patient’s discharge.
If the conversion is unsuccessful, the patient should be rescued using an appropriate transthoracic defibrillator.
Early conversion is important because a prolonged arrhythmia may be more difficult to terminate.
WARNING: Always have external defibrillation equipment available during implant and electrophysiologic
testing. If not terminated in a timely fashion, an induced ventricular tachyarrhythmia can result in the patient’s
death.
NOTE: If open chest surgery is performed and a chest retractor is used, remove it before conversion testing
to best simulate the ambulatory conditions in which the pulse generator will operate and to avoid potential
shunting of energy.
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