MRIs ok for people with pacemakers

Evidence is mounting that MRI scans may be safe for people with pacemakers or implanted defibrillators, according to the latest study on the issue that appeared in the American Journal of Cardiology.

Manufacturers currently warn against putting the devices into MRI scanners, whose strong magnetic field might in principle cause the metal wires from the devices to heat up and burn heart tissue. This could also upset the electrical properties of the delicate devices.

How the study was done

For the study, Robert Russo and colleagues at Scripps Clinic in La Jolla, California, reviewed medical records for 109 patients with pacemakers or implantable cardioverter-defibrillators. Each had undergone one or more medically necessary MRIs such as scans to look for brain tumors.

The devices were turned off during the scans or, if the patients didn't have a viable heartbeat without them, set to a constant rhythm that wouldn't be upset by the scanner's magnetic field.

There were no deaths, no device failures and no heart rhythm disturbances in any of the patients. While there were slight changes in the electrical measurements before and after the scan, they weren't deemed big enough to have any impact on the patients.

"A small number of clinically relevant changes in device parameter measurements were noted," Russo and his colleagues wrote. "However, these changes were similar to those in a control group of patients who did not undergo MRI."

Findings not definitive

Russo said the findings are not definitive and need to be confirmed in a bigger study, but he and others noted that more and more centers have started doing MRIs on patients with heart devices if there are no other good alternatives.

"With this study, and the several studies prior, there are really no clinically relevant changes that occur in 99.9 percent of the devices that get scanned," said Christopher Kramer, a spokesperson for the American Heart Association (AHA), who was not involved in the study.

Although US health regulators have already approved one MRI-compatible pacemaker, thousands of patients still live with older models. Between 50 and 70% of those might eventually need an MRI, Russo said.

(Reuters Health, August 2012)

Read more:

The different MRI scans

We live in a world where facts and fiction get blurred
In times of uncertainty you need journalism you can trust. For 14 free days, you can have access to a world of in-depth analyses, investigative journalism, top opinions and a range of features. Journalism strengthens democracy. Invest in the future today. Thereafter you will be billed R75 per month. You can cancel anytime and if you cancel within 14 days you won't be billed. 
Subscribe to News24
Voting Booth
Eskom has considered continuous load shedding at Stage 2, instead of introducing it when the power system faces a crunch. What are your thoughts?
Please select an option Oops! Something went wrong, please try again later.
Results
I'm all for it - we're going to have power cuts regardless, so we might as well have some stability to better plan our lives
45% - 4190 votes
No thanks! I prefer having periods of no load shedding and we cannot normalise this crisis
55% - 5065 votes
Vote
Rand - Dollar
17.93
-1.8%
Rand - Pound
19.45
-0.0%
Rand - Euro
17.37
-0.0%
Rand - Aus dollar
11.70
-0.0%
Rand - Yen
0.13
-0.0%
Gold
1,643.66
0.0%
Silver
18.87
0.0%
Palladium
2,073.00
0.0%
Platinum
858.50
0.0%
Brent Crude
86.15
-5.0%
Top 40
57,110
-3.1%
All Share
63,417
-2.9%
Resource 10
56,319
-7.5%
Industrial 25
78,436
-1.2%
Financial 15
14,142
-1.6%
All JSE data delayed by at least 15 minutes Iress logo
Editorial feedback and complaints

Contact the public editor with feedback for our journalists, complaints, queries or suggestions about articles on News24.

LEARN MORE