The U.S. Food and Drug Administration is warning physicians to closely watch some defibrillator wires once sold by St. Jude Medical.
The agency says failure of the wires will probably cause serious injury or death. The "leads" connect a defibrillator to a patient's heart, providing electrical shocks to restore normal heart rhythm.
The FDA warning concerns St. Jude's family of Riata leads. St. Jude has not sold the Riata leads for about a year.
St. Jude Spokeswoman Amy Jo Meyer said the FDA action reinforces advice the company gave to doctors last month.
"The FDA's classification of our physician advisory letter is part of the normal process that follows any advisory issued by a device manufacturer to physicians," Meyer said. "We've worked with the FDA to insure the news release reinforces the recommendations from the advisory letters regarding how physicians should monitor their patients."
Last month, the company informed doctors the failure rate for the wires was about six per thousand, up from a previous estimate of five per thousand.
Two people have died when surgeons tried to remove the leads. But St. Jude says no other deaths have occurred due to lead failures.
St. Jude advised physicians to closely monitor the leads. But the company said removal isn't necessary unless a lead isn't working.
The FDA says it supports St. Jude's recommendations. An estimated 79,000 U.S. patients still have the Riata leads implanted in them.