The Riata leads were recalled after the silicone coating around the wires eroded at a higher than expected rate. But the Durata lead abrasion was instead caused by scraping against another object within the body.

Defibrillators are implanted devices that use a brief electric shock to the heart to restore normal heartbeat.

Shares of the medical device maker fell 6 percent on June 12 after a physician report filed with U.S. regulators said a Durata lead wire had failed in a single patient -- raising fears of another product recall.

St. Jude late on Friday said the Durata lead was removed from a patient at a Florida hospital and then examined there by one of the company's senior lead investigators.

"Our analysis indicates the damage to the Durata lead is consistent with external abrasion from contact with a calcified, or hardened, heart valve" or possibly from contact with another implanted lead, the device maker said in a release.

The company said the abrasion was "different from the inside-out abrasion" seen in the Riata leads.

Shares of St. Jude, which announced its findings shortly before the close of trading on the New York Stock Exchange, ended up 96 cents, or 2.6 percent, at $37.90.

(Reporting By Ransdell Pierson; Editing by Bernard Orr)

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