WASHINGTON, Dec. 14 (UPI) -- U.S. Food and Drug Administration researchers say they have identified a new magnetic resonance imaging safety risk for patients with pacemakers.
The FDA said some cardiac pacemakers might inadequately stimulate the heart while the patient is undergoing a MRI scan because of the strong magnetic pulses mixing with the electronic pulses produced by the pacemaker. The inadequate stimulation is potentially dangerous for the patient, the researchers said.
FDA researchers Howard Bassen and Gonzalo Mendoza evaluated the risk of pacemakers causing unintended cardiac stimulation following exposure to a simulated MRI magnetic field by measuring electrical voltage produced at the tip of the pacemaker lead, where it would touch the interior of the heart.
They said they found that when exposed to the strong, "gradient," magnetic field, the pacemaker could deliver a drastically altered pulse and stimulate the heart inappropriately, which could have devastating consequences for the patient.
"MRI systems emit several types of extremely intense magnetic fields and have caused injury to patients due to interactions with pacemakers," said Bassen. "Cardiologists who choose to scan patients with cardiac pacemakers must assess the risks versus the benefits of the scan.
"This paper identifies one more risk," he added.
The research is reported in the journal BioMedical Engineering Online.
