Best and Brightest: Testing MRI-Safe Pacemakers

Edward J. Schloss, Medical Director of Cardiac Electrophysiology at The Christ Hospital, was the first in the nation to implant a new MRI-safe pacemaker.


A traditional pacemaker’s job is to keep the heart from going too slow or to speed the heart up if the body’s asking for a faster heart rate. The most exciting new pacer technologies we have are pacers that are compatible with an MRI scan. Traditional pacers are considered contraindicated in MRI scanners for a variety of reasons, including pacer sensitivity to the electrical and magnetic fields emitted by the scanner—this can look like cardiac activity and thereby “fool” the device into pacing at the wrong rate—and pacer leads acting like antennae, concentrating energy to the heart, and adversely affecting the heart tissue. The design of both the hardware and software is modified to work around these issues in the MRI-compatible device. As a fella who’s had an MRI for torn knee cartilage, I know if I had told my surgeon that I couldn’t get an MRI, it would have made my care a little more difficult.

We were privileged here at Christ to be involved in the early research [of the original MRI-compatible pacemakers], which goes back to 2008; more recently we were the first in the country to put in the next generation device, sort of the 2.0 version. 

The procedure from where the patient sits with MRI-compatible devices is very similar [to the procedure with traditional pacemakers]. They’re a bit thicker, but that doesn’t really translate into anything important to the patient that we’ve been able to discern. I tell my patients it’s the long-term track record—as with any new product—that’s not as well known. We don’t anticipate any problems, but that’s why we’re doing the trial.

It’s important for people to know that these pacemakers exist. I think it’s probably not common knowledge to patients that they may not be able to get an MRI if they get an implantable device. There may be times where their doctor, for good reason, would tell them: “You’re not the right patient for this.” Sometimes it doesn’t have the features that the patient needs. There is only one currently available manufacturer and model, so many patients opt to use a system that has a longer track record to mitigate risk. But to have it as a starting point in the conversation is really critical.

It’s early enough right now that we are really just starting to collect data. We had a patient who got the MRI as part of the research trial, and we found a tumor. It was a nice success story: We made an early diagnosis on something that would potentially have been life-threatening.

It doesn’t mean that everybody should be getting scanned. That decision is best done between the patient and the doctor who knows them well. But it’s nice to know you have the options and all the imaging available to you.

Originally published in the January 2012 issue.

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