The problem with Guidant's pacemakers poses less of a risk for patients than those with its defibrillators because of the relatively small number of pacemakers implanted and because the malfunction occurs gradually.

The Indianapolis-based company, which last month recalled almost 109,000 defibrillators, released a warning that says a sealing component in the pacemakers has degraded in some cases, resulting in higher-than-normal moisture in the devices and possible malfunction.

About 78,000 of the pacemakers were distributed, with about 18,000 remaining in US patients, the company said in the statement. The devices, which send electrical pulses to the heart to correct a slow heart beat, have a seven- to 10-year life span before they must be replaced.

Guidant said it has identified 69 failures among the pacemakers -- all after they had been used for at least 44 months. The models include: Pulsar Max, Pulsar, Discovery, Meridian, Pulsar Max II, Discovery II, Virtus Plus II, Intelis II, and Contak TR.

The company told physicians they should consider replacing the devices for patients who are dependent on the devices. Pacemakers are about the size of two half dollars held together.

Several patients implanted with the devices have lost consciousness or developed possible heart failure, Guidant said. It reported the death of one person whose pacemaker may have failed, but said the role of the device could not be confirmed as the device was not returned for testing.

Food and Drug Administration spokeswoman Julie Zawisza said the agency was evaluating Guidant's warning. Guidant said the FDA may classify the warning as a recall. The company issued two safety warnings last month for 11 models of defibrillators that were later classified by the FDA as recalls.

Defibrillators are also implanted devices; they shock the heart back into rhythm when it beats too quickly. Almost 88,000 of the Guidant devices that were recalled remain implanted worldwide.

The problem with Guidant's pacemakers poses less of a risk for patients than those with its defibrillators, according to Dr. Angel Leon, chief of cardiology at Emory Crawford Long Hospital in Atlanta. That's because of the relatively small number of pacemakers implanted and because the malfunction occurs gradually, allowing patients more time to seek advice.

Leon also said he expects more warnings from medical-device manufacturers including Guidant, as the companies respond to criticism that they've withheld safety information.

"Every manufacturer of these devices has had failures, has had recalls and has had advisories," he said. "It will continue to happen. It's how the companies handle the recalls that's important."

Guidant said that it would replace the pacemakers at no charge through the end of the year, even though the warranty on many has expired, and that it would reimburse patients up to $2,500 for medical expenses.

The company, which has faced a barrage of criticism from patients and physicians on its handling of the recalls and warnings, also said in its statement Monday that it has planned to set up an "independent panel of experts to recommend guidelines for when to disseminate information" on its devices.

Shares of the company fell $1.11 to $68.30 in midday trading on the New York Stock Exchange; they have traded in a 52-week range of $49.95 to $75.15. On June 24, following the second of two recalls, shares sank 6.9 percent, or $4.70, to $63.90.

Those levels compare with $76 per share offer from Johnson & Johnson, which Guidant shareholders voted to accept in April. The $24.5 billion cash-and stock-deal is still pending.

Analyst Hemant K. Shah of HKS & Co. said it is possible that J&J will be able to negotiate a lower purchase price since Guidant's share price has fallen. "J&J is clearly committed to medical devices," he added.

Jeffrey Leebaw, a spokesman for New Brunswick, NJ-based Johnson & Johnson, said Monday the company stood by its June 17 statement that it was still working to close the acquisition in the third quarter. It called the initial safety advisories "serious matters."

A.G. Edwards & Sons analyst Jan Wald said Guidant's newest warning follows continued internal scrutiny about potential malfunctions in its products and was unlikely to jeopardize the planned acquisition.

"I think it's a company going through their files," he said. "They've gone through their defibrillator product line. Now they're going through their pacemaker product line."

Guidant's second-quarter earnings are to be released Thursday.