Medical devicemaker Medtronic warned doctors this week that wires on some of its Sigma pacemakers could separate, preventing them from working.
Medtronic said it has spotted the wire problem in 19 devices, or 0.05% of that class of Sigma pacemakers. It estimated that perhaps 0.17% to 0.30% of the devices might develop the problem over the device's projected 10-year life.
Medtronic said the wire problem might show up in patients in ways that included battery depletion, no pacing output, and a failure to keep up with a faster heartbeat during activity such as exercise.
Medtronic spokesman Rob Clark said problems in 14 of the 19 pacemakers were discovered because the device failed to work properly, causing symptoms such as dizziness or fainting for some of those patients. No patient deaths or injuries have been associated with the problem, according to Medtronic.
The advisory to doctors covers about 28,000 pacemakers sold worldwide, including approximately 6,650 in the U.S., the company said.