Effects of Magnetic Resonance Imaging (MRI) on St. Jude Medical Implantable Cardiac Rhythm Devices

Background

Magnetic Resonance Imaging (MRI) is contraindicated by MRI manufacturers for patients with implanted cardiac rhythm management devices, including both pacemakers and implantable cardioverter defibrillators (ICDs), unless the leads and device are labeled for MRI use. Clinicians should carefully weigh the decision to use MRI with ICD or pacemaker patients with systems that are not labeled for MRI use. MRI may cause device malfunction or injury to the patient. The powerful magnetic and radiofrequency fields generated by MRI systems may cause inappropriate operation or permanent damage to implanted pacemakers or ICDs.

Potential Effects

Potential effects of MRI exposure range from single-beat inhibition of pacing to component damage leading to inappropriate operation or device failure.

  • Magnetic and RF fields produced by MRI may increase pacing rate, inhibit pacing, cause asynchronous pacing or result in pacing at random rates.
  • MRI may result in changes in capture thresholds due to heating of pacing leads in any patient.
  • MRI may irreversibly damage the pulse generator.

A summary of potential effects is provided in the table on page 2 and is based on device testing at St. Jude Medical, clinical experience and a review of the scientific literature.

Potential Effect Estimated Frequency
  Pacemakers ICDs
Reversion to magnet mode Common Common
Asynchronous pacing/noise reversion Common Common
Single-beat inhibition Common Common
Permanent loss of RF telemetry Common Common
Lead dislodgement on acute leads Uncommon Uncommon
Device movement in the pocket Uncommon Uncommon
High rate pacing Rare Rare
Lead heating, possibly leading to tissue damage andpacing threshold changes Rare Rare
Arrhythmia induction Rare Rare
Component damage Rare Rare
Inappropriate therapy delivery Not applicable Rare
Failure to deliver needed therapy Not applicable Rare
Reset mode Not applicable Rare

Recommendations

Clinicians should carefully weigh the decision to use MRI with pacemaker or ICD patients. If MRI must be performed, please refer to the 2017 HRS Expert Consensus Statement on MRI for recommendations.

If you have any questions please contact St. Jude Medical CRM Technical Services.

PDF Effects of Magnetic Resonance Imaging (MRI) on St. Jude Medical Implantable Cardiac Rhythm Devices (77.8kb)
Rev 06/17