Health Canada has given the green light for a new pacemaker that allows patients with the devices to enter magnetic resonance imaging machines without risk of injury.

Dr. Anne Gillis, a professor of medicine at the University of Calgary, says patients with pacemakers have been warned against the risks associated with MRIs.

MRIs are especially effective for viewing the brain, heart, muscles and other soft tissues to aid diagnosis of cancer, injury or disease.

But Gillis says there have been concerns the device can improperly pace the heart or burn heart tissue at the tip of the pacemaker lead.

Gillis says the new pacemaker created by Medtronic Inc. of Mississauga, Ont., has redesigned components and circuitry that eliminates the risk.

She says the average patient needing a pacemaker is 73 — an age when MRIs are often needed to determine other health problems.