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MRI no longer off limits for pacemakers

JOHNS HOPKINS (US) — Patients with cardiac implants can safely undergo MRI scans if their doctors follow new guidelines, researchers say.

MRI—or magnetic resonance imaging—has been off limits to more than 2 million people in the United States who have implanted pacemakers to regulate heart rhythms or implanted defibrillators to prevent sudden cardiac death.

“The guidelines we have published can be used to make MRI more available to people who could benefit from early detection of cancer and other diseases and for guiding surgeons during procedures,” says lead researcher Saman Nazarian, a cardiac electrophysiologist and assistant professor of medicine at Johns Hopkins University.

MRI is considered superior to CT scans in many clinical scenarios, especially for brain and spinal cord imaging, says Nazarian. To date, more than 700 patients with implanted cardiac devices have safely undergone MRI exams at Johns Hopkins.

The study of the new protocol, published this week in the Annals of Internal Medicine, followed 438 people with implanted cardiac devices who had 555 MRI scans. Almost all of the exams, 94 percent, were conducted at The Johns Hopkins Hospital. The rest were performed at Rambam Medical Center in Haifa, Israel.

The researchers found that with appropriate precautions, patients with pacemakers and defibrillators can have an MRI scan with very low risk of the device malfunctioning, moving, heating, or causing abnormal heart rhythms due to the magnetic and radiofrequency energy generated by the test.

The devices implanted in three of the patients in the study had a power-on reset event during an MRI scan, which means the energy emitted from the scanner caused the devices to revert to default settings. This is a rare occurrence that warrants close expert monitoring during the test, but is easily remedied after the test is completed. None of the three had device dysfunction during the long-term follow-up of between 15 and 66 weeks. One of those patients completed four repeated MRI examinations during the study without any problems.

Johns Hopkins cardiac electrophysiologist and biomedical engineer Henry Halperin began researching the issue of MRI safety with implanted devices about 15 years ago, testing a range of devices. The safety protocol he developed is now being adopted by institutions around the world.

“The newer pacemakers made after 1998 and defibrillators manufactured since 2000 come with electromagnetic interference protection,” says Halperin, who is a professor of medicine and the study’s senior author.

In addition to the age of the device, the Johns Hopkins team checks the type and configuration of the leads attached to the device. For example, if a lead is disconnected and not functional, an MRI would not be recommended because the tip of the wire could get very hot.

“We reprogram the device to a safe mode while the patient is having the MRI scan,” says Rozann Hansford, a nurse and study author who monitors patients at Johns Hopkins during scans. “We carefully monitor the patient’s blood pressure, electrical activity of the heart, and oxygen saturation, and look for any unusual symptoms. After the test, we reprogram the device and carefully check its function.” The patients’ devices are checked again in three to six months.

The researchers conclude that with a protocol based on device selection, programming and careful patient monitoring, MRI can be performed safely in many patients who have a pacemaker or a defibrillator.

“With the advancing age of the population and the expanding indications for pacemakers and defibrillators, this has become an increasingly important issue, and a lifesaving one for some patients,” Nazarian says.

He adds that many of the patients with cardiac devices who have come to Johns Hopkins for an MRI scan had tumors and other serious problems diagnosed and treated, whereas those problems had been missed by a previous imaging test such as a CT or ultrasound exam.

More news from Johns Hopkins University: http://releases.jhu.edu/

chat19 Comments

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19 Comments

  1. richard jordan

    i am due to return to bayview hopkins this year for a follow up mri for a pituitary macroadenoma. since my last visit, i had a pacemaker implant……with a medtronic model RVDR01. i travel from the virgin islands. would i have to return for a check up before my regular yearly visit?

  2. Dennis O'Shea

    Dear Mr. Jordan: I’d urge you to check directly with your doctor on that question. Those of us here at the university who work with Futurity are in the communications office, and we’re not qualified (far from it!) to give you any medical advice. Best regards,
    Dennis O’Shea

  3. denise cooper

    My dad has severe hip pain and back pain. His dr. would like to run an mri but he has a pacemakerl My dad is 77 years old and in very good health, He drives and still feeds his cattle and has been very active but the pain is beginning to hinder his lifestyle. Is there a possibility that he could have an mri run and if so, where?

  4. Rigoberto

    thi is great news!! I am 52 years old, i have medtronic pacemaker sen 2001 i been suffering with upper end lower back pain for several years with difficult to walk ,i can not work i am disabled.please what i have to do, I am eligible for a MRI?

  5. Dennis O'Shea

    Dear Rigoberto: I’m very sorry to hear about your pain. As I said in the posting above, I am not a doctor (I work in the university’s communications office), so I would urge you to ask your doctor about how these new guidelines apply to your case. Good luck! — Dennis O’Shea

  6. Ted Shaffer RN

    I stumbled across this web page in an internet search I was doing on pacemaker protocols. I am a Registered Nurse in a cardiac telemetry unit with the Veteran’s Affairs (VA) hospital in Tampa Florida. I am curious to know if the protocols from the research Johns Hopkins has conducted is being shared with other hospitals. I noticed from the above reading, that there was a journal article published in the Annals of Internal Medicine regarding the protocol. I have not had a chance to review that article but would be curious to learn more about the findings. As a nurse, I am always compelled to seek out new evidence-based practices and implement them for the betterment of our patient population. The benefit of being able to perform MRIs on patients with pacemakers and defibrillators could be life enhancing for many. any information you can provide would be helpful.

  7. Eileen S. Smith

    Right now, are the only two places that perform MRI’s on people with pacemakers Johns Hopkins in Baltimore
    and Haifa, Israel? If you know of any other centers, I would appreciate knowing them. I am in the northeast – Long Island, New York. Many thanks.

  8. James Lucas

    At Scripps, Lajolla, CA, I was told that here are 31 hospitals in the western USA that are doing MRI’s on people with pacemakers. I am currently endeavoring to get a list of them. When I receive the list I will post it.

  9. O.P. Saxena

    I am 83 years old. I have a pacemaker (Medtronic) implant in November 2005. I have been suffering from backache, intense pain in the legs, numbness and swelling in my feet, making it difficult to walk. Is it possible to get MRI done in India?

  10. Rebecca Rogers

    I am very curious to know if J.H. is the only place in the U.S. that is practicing MRI’s with people that have pacemakers? I live in Ohio and have been having some stomach issues. They have done every test available to me except an MRI because I have a pacemaker. I am to the point that if J.H. is the only place that does this to be booking a plane ticket and flying out there to have it done. Any information would be helpful. Thank you! R.R.

  11. Jim Lucas

    There are many places that do MRIs on us people with pacemakers. To find places that do MRIs on people with pacemakers, go to http://www.clinicalTrials.gov. Once at http://www.clinicalTrials.gov search for MagnaSafe and scroll down to locations. Good luck and good hunting.

  12. MRI-Geek

    OHSU -Oregon Health & Science University is now the new place in the NorthWest, where they are now starting to MRI scan patients with pacemakers and implanted defibrillators.

    Call for an appointment and screening interview.

    OHSU
    3181 S.W. Sam Jackson Park Rd.
    Portland, Oregon 97239-3098

    Switchboard
    503 494-8311

  13. UNVRKNW

    I understand that Emory University (Atl GA) does this MRI. I had the understanding that the pacer was not so much the issue but the wires placed in the heart itself. Otherwise, why do they ask questions about implants and watches etc that are magnetic. I ruined watch once by forgetting to remove it.

    I have MS and a pacer and am concerned about this procedure. Maybe I can be convinced.

  14. Martin Carlton

    I have a Boston Scientific pacemaker for 7 years. I have developed sever hip and lower extremety pain and my Orothepedic Surgeon would like to have me get an MRI. I have had a CAT Scan and Bone Scan and a nurological exam and still have not been able to determine what the problem is. I am living in Florida at present but would travel anywhere to get a MRI. Could you please advise me where I could go.
    Thank you.

  15. Don Kinderman

    I live in southern Oregon. I have severe balance problem. This has been going for 2 years.
    I would like a MRI that perhaps could find the problems. I have a Pace Maker.
    Could you help me with this?
    Don
    541 941-4707

  16. D.Zinger

    I think any Cardiology EP Doctor would actually be quite interested in a directory of such MRI Practices by location for their patients! Something that should absolutely be considered.

  17. Cardiology EP

    D. Absolutely agreed. Though I think such already exist, no?

  18. Angeline WILLERS

    I have debilitating low back pain extending down to my toes plus extreme knee pain,To the point of unbearable. Can only be active short time.Family think c-t scan to dangerous,Neurologist wont consult with out a new picture.Any way in Sioux Falls S,D, or Minneapolis area that would do a MRI with a Bostion Sientifet pace Maker since Feb. 2011, Getting desprite

  19. Anne Bayley

    I am researching MRI conditional pacemakers and came across this article. Where can I get the full written study from as I dont have access to the Annals? I am really interested in what pacemakers were scanned, whether the protocols were adapted to scan the patients, the MRI scanner that was used and how long the patients were scanned for. Appreciate any feedback to the above email thanks.

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