Earlier this month, Guidant stood by its decision to continue selling the Prizm 2 DR for months after a potential flaw prompted a redesign, saying the original device was still reliable.

At least two patients with the devices have died, and the Indianapolis-based company said its devices had failed at least 45 times. Guidant said it was advising physicians about the safety of several models.

The company said it would replace 28,900 of the implanted defibrillators if requested because the potential flaw couldn't be fixed without removal. More than 20,000 of those are used by patients in the United States.

Another 21,000 devices -- 18,000 used by US patients -- can be fixed by external reprogramming, the company said.

Under Fire

The US Food and Drug Administration advised patients to see their doctor and said it would not recommend whether individual patients with one of the recalled devices should have them removed and replaced.

Implantable defibrillators are intended to sense an irregular heart rhythm and shock the heart back into correct beating.

"This is a voluntary recall," US Food and Drug Administration spokeswoman Julie Zawisza said. "We're in complete agreement that they need to do that."

Guidant came under fire this spring after reports that it failed to alert physicians about potential problems with the Ventak Prizm 2 DR model defibrillator.

Friday's recall includes that model and the Contak Renewal and Renewal 2; the Ventak Prizm AVT; Vitality AVT; Renewal 3 AVT; and Renewal 4 AVT ICDs. The company said about 63,000 of the devices had been implanted, with nearly 50,000 still in use.

Guidant said patients implanted with those devices should continue to see their doctors at three-month intervals and any patient who recently received a defibrillator shock should consult with their physician.

The company said a programming change can be performed for the Prizm AVT, Vitality AVT and Renewal AVT devices at a physician's office to reduce the risk of a short circuit, while defective Prizm 2 DR and Contak Renewal devices will be replaced at no charge.

"Patient safety is paramount and our highest priority," Guidant CEO Ronald W. Dollens said in a statement. "Guidant takes seriously its responsibility to create the most reliable products and services, enhance patient outcome and limit adverse events to patients."

Electrical Flaw

Earlier this month, Guidant stood by its decision to continue selling the Prizm 2 DR for months after a potential flaw prompted a redesign, saying the original device was still reliable.

In April, the company told doctors that the Prizm 2 DR defibrillator had failed in a small number of cases because of an electrical flaw. It also said that it had fixed the flaw in devices made after mid-2002.

No failures in the Prizm 2 DR has been reported since April 2002. The faulty Contak Renewal defibrillators were manufactured on or before Aug. 26, 2004, Guidant said.

A Pennsylvania man sued Guidant on June 1, claiming the company is financially liable to all patients implanted with one of its heart defibrillators because it did not tell them the devices could short-circuit. Lawyers for 74-year-old John Brennan said they hoped to make the legal complaint into a class-action lawsuit.

Shares of Guidant fell 80 cents, or 1.1 percent, to $72.86 in afternoon trading on the New York Stock Exchange, where they have traded in a 52-week range of $49.95 to $75.15.

Guidant shareholders in April voted overwhelmingly in favor of a planned $25.4 billion acquisition by Johnson & Johnson. The merger, which still must win regulatory approval in the United States and Europe, would be the largest business deal in the 119-year history of New Brunswick, N.J.-based health care products giant J&J. J&J has said it expects to complete the acquisition during the third quarter.

Johnson & Johnson did not immediately return a message.