Pacemakers and MRI scanners have never mixed well. The powerful magnetic field of the MRI scanners can interfere with the operations of a pacemaker in ways that can damage the device and possibly even accidentally shock the heart.
The result, according to the Los Angeles Times, is that an estimated 200,000 Americans who rely on pacemakers for heart care, most of them elderly, have to forgo an MRI scan each year.
But now the Food and Drug Administration has approved its first MRI-safe pacemakers. The Revo MRI SureScan pacing system, developed by Minnesota-based Medtronic Inc., has electrical leads with modified internal wiring to decrease the risk of overheating. It also has a “safe mode” that is activated before a scan to prepare patients for the MRI.
“FDA’s approval of the Revo pacemaker represents an important step forward toward greater device innovation,” Dr. Jeffrey Shuren, director of the FDA’s Center for Devices and Radiological Health, said in a news release. “Those patients who meet the parameters for the device will be able to maintain their critical cardiac therapy while benefiting from the precise diagnostic capability of an MRI.”
The FDA approval followed a review of a clinical trial of 484 patients. Of those, 464 were successfully implanted with the new pacemaker and none of the 211 who underwent an MRI suffered an MRI-related complication. Medtronic has agreed to conduct further studies of the device.
MRIs, or magnetic resonance imaging exams, are being used increasingly to diagnose ailments because they provide precise pictures of internal organs and soft tissues.


