Related Experiment Videos
Do we need pacemakers resistant to magnetic resonance imaging?
Werner Irnich1, Burkhard Irnich, Christine Bartsch
1Department of Legal Medicine, University Hospital, Giessen, Germany. werner.irnich@technik.med.uni-giessen.de
Summary
Magnetic resonance imaging (MRI) is generally contraindicated for pacemaker (PM) patients. However, this study found that asynchronous pacing is the main risk, and MRI-triggered scans can be safely performed in PM patients, even those with spontaneous rhythm.
Area of Science:
- Biomedical Engineering
- Cardiology
- Radiology
Background:
- Pacemaker (PM) and magnetic resonance imaging (MRI) device manufacturers contraindicate MRI scans for PM wearers.
- Potential risks include interference with PM function and patient safety concerns.
Purpose of the Study:
- To investigate the effects of MRI on pacemakers.
- To identify hazardous interactions and propose modifications for safe MRI procedures in PM patients.
Main Methods:
- Tested pacemakers from deceased patients in varying magnetic fields.
- Assessed reed switch thresholds, gradient field influence, and radiofrequency (RF) heating.
- Surveyed legal medicine departments regarding PM patient deaths during MRI.
Main Results:
- Reed switches are affected above 0.7 mT; pacemaker function varied with orientation in MRI fields.
- Gradient fields influenced sensing but not stimulation; RF heating decreased with distance.
- Six deaths were reported, primarily due to ventricular fibrillation in non-PM-dependent patients.
Conclusions:
- Asynchronous pacing is a concern in PM patients with spontaneous rhythm.
- MRI-triggered scans, restricted to the pacemaker's refractory period, are proposed as a safe alternative.
- Neither PM inhibition nor electrode heating posed significant risks in tested patients.