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Studies Show Pacemakers and ICDs Have a Future with MRI Scanning

 It is believed that MRI’s and pacemakers (or implanted defibrillators) don’t go well together.  Even MRI manufacturers warn against usage on patients with pacemakers.  It has been suggested that the magnetic resonance imaging would negatively affect the pacemaker’s ability to function, causing the metal wires to heat up, which would burn the heart tissue and possibly even thwart the electric properties.  However, this is all theoretical! Research has been done to prove differently and could mean new options for patients with pacemakers.

Dr. Robert Russo and his colleagues at Schripps Clinin in La Jolla, California, looked at medical records from 109 patients with pacemakers or ICDs.  Every 1 out of 109 had at least one necessary MRI and during the procedure the pacemakers were either turned off or set to a constant rhythm, for those who would not have a viable heartbeat without them that would not be disturbed by the magnetic field.

According to this study, published in the American Journal of Cardiology, there were no deaths, none of the devices failed and no heart rhythm disturbances occurred in any of the patients.  Some of the electrical measurements taken before and after the scan were slightly different, although the changes were not considered large enough to have an affect on the patients’ health.

The researchers also studied 50 patients with heart devices that never had an MRI scan, helping to indicate the variation in the electrical measurements to be normal.  However, the findings are not yet complete and need a larger study, like the MagnaSafe Registry, which Russo is already working on.

Russo said, “If it is clinically necessary, the clinician needs to weigh the risk and benefits on a case-by-case basis,” about patients with pacemakers needing MRIs.  Also, Kramer and Russo both said that more centers are beginning to do MRIs on patients with these devices when MRI is the safest option.

Although the U.S. health regulators have approved one MRI-compatible pacemaker, thousands of people still have the older models and they say about 50-70% of those people will need an MRI eventually.

Dr. Christopher Kramer, who was not involved in the work, a spokesperson for the American Heart Association, said, “With this study, and the several studies prior, there are really no clinically relevant changes that occur in 99.9% of the devices that got scanned.”  Although Kramer speaks about this study, the AHA is not endorsing MRI for pacemaker patients just yet.  Medicare will not pay for the scans either unless they are part of a registry being used to study the safety of the procedure.

For more information, read the article or look at the study in the American Journal of Cardiology.