Effects of Implantable Biostimulators on St. Jude Medical Implantable Cardiac Rhythm Devices

Background

Biostimulators are an integral component of surgically implanted systems, such as neurostimulation, deep brain, vagus nerve, bladder incontinence, and dorsal or paravertebral column stimulation. These implanted systems are designed to treat a variety of disorders. These systems include the neurostimulators made by St Jude Medical.

Potential effects

Although we have had no reports from the field of any interference, the electrical signals from the biostimulator system can interfere with the normal operation of pacemakers and implantable cardioverter defibrillators (ICDs). If the biostimulator does interfere with the pacemaker, either inhibition or reversion to asynchronous pacing may occur. Bipolar pacemakers are much less likely to be affected by interference than are unipolar pacemakers.

The electrical impulses from the biostimulator may be interpreted as “electrical noise” in ICDs and cause a noise reversion. During a noise reversion the device will not deliver therapy (therapy includes ATP pacing, cardioversion and defibrillation). If biostimulator impulses are misinterpreted as cardiac events in an ICD, inhibition of bradycardia pacing and/or inappropriate arrhythmia detection and therapy delivery are possible. Extraneous signals from the biostimulator will not cause any damage to the pacemaker or ICD.

The magnet supplied with some of the biostimulators may temporarily cause asynchronous pacing in pacemakers and may temporarily disable tachycardia detection and therapy in ICDs when applied in close proximity to the pacemaker or ICD.

A summary of potential effects is provided in the table below and is based on device testing at St. Jude Medical, clinical experience and/or a review of the scientific literature.

Potential Effect Estimated Frequency
  Pacemakers ICDs
Inhibition of pacing Rare Rare
Asynchronous pacing/noise reversion Rare Rare
Inappropriate therapy delivery Not applicable Rare


Recommendations

  • It is recommended that the biostimulator be tested for possible interactions with the pacemaker or ICD after it is implanted. This testing could be done by programming the biostimulator to its highest output in its intended stimulation configuration and the pacemaker or ICD to its most sensitive setting and then monitoring the patient on an ECG to determine whether or not the biostimulator is causing oversensing that may interfere with the function of the pacemaker or ICD.
  • Per the 2011 HRS perioperative consensus committee, it might be necessary to demonstrate that spinal cord stimulation during ventricular fibrillation (VF) does not cause problems with sensing1.
  • The biostimulator should also be tested in all modes directly programmable by the patient (e.g. Burst, stimulation set#1, Stimulation set #2, stimulation vectors) at the highest output amplitude settings available.

If you have any questions on this topic, please contact CRM Technical Services.

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EMI TI16‐104

REFERENCES


1. Crossley, G., Poole, J., et al.: The Heart Rhythm Society Expert Consensus Statement on the perioperative management of patients with implantable defibrillators, pacemakers and arrhythmia monitors: Facilities and patient management. Heart Rhythm, 2011.