Guidant Corp. is warning doctors to stop using five defibrillator models because they could malfunction and may have to be recalled. It's the second safety announcement in a week from Guidant, which earlier recalled seven defibrillator models.
The devices included in the latest recall are the Contak Renewal 3 and 4, Renewal 3 and 4 AVT and Renewal TF, the U.S. Food and Drug Administration (FDA) said.
"Guidant has determined that the devices listed above are subject to a component failure that may limit available therapy," the company said. "We have determined that a magnetic switch in these devices may become stuck in the closed position, which in some cases inhibits the device's ability to treat ventricular or atrial tachyarrhythmias and can accelerate battery depletion."The agency said that four malfunctions have been confirmed and a fifth is suspected. In the four confirmed incidents, patients or physicians were alerted to the condition by audible tones that signaled the magnetic switch was closed.
The four devices have been replaced and there have been no documented patient injuries.
Guidant said physicians should reprogram the defibrillators so their magnet use is off. The devices will continue to function. Patients who hear beeping tones from the defibrillators, however, should go to the emergency room immediately.
