Harvard Heart Letter

Getting an MRI if you have a pacemaker

Ask the Doctor

Q. I've had a pacemaker for several years. Does it make sense to replace it with a newer model that is safe during an MRI scan?

A. Your concern is valid, given some estimates that many people who currently have an implanted cardiac electronic device will need magnetic resonance imaging (MRI) during their lifetime. Sometimes, computed tomography (CT) scans can be used instead. But MRI is the gold standard for diagnosing certain diseases of the brain and spinal cord.

Implanted cardiac devices (which include both pacemakers and defibrillators) can be damaged by an MRI scan. The powerful magnets can trigger changes in a pacemaker's settings, and this may pose a risk for certain patients, such as those who are completely dependent on their pacemaker.

As you note, several MRI-safe pacemakers have been approved by the FDA in recent years. However, it doesn't make sense to switch your old pacemaker with an MRI-safe model, as the procedure to replace the generator carries some risks. Still, if you end up needing MRI, there are special protocols that doctors can use to minimize the risks. They include setting the pacemaker to a safe mode before the scan, monitoring you closely during the procedure, and reprogramming the pacemaker afterward. You and your physician would need to carefully weigh the risks and benefits of all your options.