Magnetic resonance imaging tests are increasingly being used for diagnosing forms of heart disease and for a wide range of other ailments, at the same time that more and more people are receiving ICDs and pacemakers. Just what are the risks to patients and to devices themselves?
Medtronic's REVO MRI stands to be the first pacemaker FDA-approved specficially for patients undergoing MRI scans, after FDA's Circulatory System Devices advisory panel voted unanimously in favor of recommending the agency approve it.
UPDATED // Patients with pacemakers are not allowed in an MR scanner because of concerns about induced arrhythmias and overheated leads, but this study showed no complications and no changes in temperature at the tip of the lead. Investigators say this is good news, considering the growing number of pacemaker-implanted patients who require an MRI scan.
The AHA has issued a scientific statement on the safety of MRI in patients with cardiovascular devices. For most devices, if there is a good clinical indication for MRI, the benefits of scanning outweigh the risks, the lead author says. The exceptions to these are pacemakers and ICDspatients with such devices should receive MRIs only if needed and only then in expert centers, he says. (Levine GN et al. Circulation; published online before print November 19, 2007.)
New in vitro and animal testing suggests that MRI might be safely offered to patients with most types of pacemakers and ICD models manufactured after the year 2000. Such devices are currently considered a contraindication for MRI. (Roguin A et al. Circulation 2004; 110:475-482.)