Evidence is mounting that shows MRI scans are safe for those with pacemakers or implanted defibrillators, according to a new study published in the American Journal of Cardiology.
Manufacturers have warned in the past against putting the devices into MRI scanners, whose strong magnetic field could cause the metal wires to heat up and burn heart tissue, reports The Chicago Tribune. The electrical properties of the delicate devices could also be upset by the scanners.
Robert Russo and colleagues at Scripps Clinic in La Jolla, California reviewed medical records for the study, looking at 109 patients with pacemakers or implantable cardioverter-defibrillators. Each of the 109 patients had gone through at least one MRI scan, like those to look for brain tumors.
The implanted devices were turned off or, if the patients didn’t have a viable heartbeat without them, set to a rhythm that wouldn’t be upset by the MRI scanner’s magnetic field. Russo and his colleagues wrote that:
“A small number of clinically relevant changes in device parameter measurements were noted. However, these changes were similar to those in a control group of patients who did not undergo MRI.”
Fox News notes that more and more research like this is showing that the worries about MRI scans affecting implanted devices like pacemakers could be unfounded. Dr. Christopher Kramer, a spokesperson for the American Heart Association, who was not involved in the new study, stated that:
“With this study, and the several studies prior, there are really no clinically relevant changes that occur in 99.9% of the devices that get scanned.”
Despite the new evidence, the AHA does not endorse MRI scans in pacemaker patients. Medicare will also not pay for the scans, unless the patients are part of a registry that is used to investigate the safety of the theory. In the 109 patients whose records Dr. Russo studied, there were no deaths, device failures, and no heart rhythm disturbances.
Russo also stated that, while the evidence shows pacemakers are not affected by MRI scans, a bigger study, like the MagnaSafe Registry, needs to be completed in order to know for sure.