THURSDAY, May 18, 2006 (HealthDay News) -- More than one in five external defibrillators, which are often placed in public places to revive heart attack victims in emergencies, were recalled because of potential malfunctions, new research shows.
The data, based on 10 years of U.S. Food and Drug Administration records, provide some of the first evidence on the safety and reliability of automated external defibrillators (AEDs). The findings were presented Thursday at the Heart Rhythm Society's annual meeting in Boston.
"AEDs provide automated heart rhythm analysis, voice commands, and shock delivery, and can be used by individuals with minimal training or experience," study author Dr. William H. Maisel, director of the Pacemaker and Device Service at Beth Israel Deaconess Medical Center, said in a statement. "As a result, widespread installation of AEDs has occurred in recent years."
"Public places such as airports, sports arenas and casinos are now routinely outfitted with AEDs and the U.S. Food and Drug Administration [FDA] has approved certain AED models for home use," he said. "Unfortunately, as AED use has increased, so too has the number of recalled devices."
The annual number of the devices distributed between 1996 and 2005 increased almost ten-fold, from fewer than 20,000 to nearly 200,000. During that same period, the study authors found the FDA issued 52 advisories involving either AEDs or critical AED accessories, affecting a total of 385,922 devices.
"The results showed that during this 10-year study period, more than one in five AEDs were recalled due to a potential malfunction," said Maisel, who added that electrical and software problems were the most common reasons for the advisories. The number of devices that were recalled also increased significantly over time.
In a separate analysis of FDA data, the researchers found that 370 confirmed AED malfunctions occurred during attempted resuscitation of cardiac arrest victims.
But Maisel stressed the findings should not scare people away from using these devices in an emergency.
"While AED malfunctions do occasionally occur, the number is small in comparison to the number of lives saved by these important devices," he said. "However, because the number of AEDs in distribution continues to increase rapidly, efforts should be directed at developing a reliable system to locate and repair potentially defective devices in a timely fashion."
In separate research presented at the same meeting, Mayo Clinic doctors said a five-year review of the replacement of potentially faulty internal -- implanted -- defibrillators at that center found a complication rate of about 1.24 percent. A similar Canadian study found an 8.1 percent complication rate. The complications included infection and blood clots.
Use of these devices, which deliver a shock to restart a malfunctioning heart, has also exploded in recent years. However, along with that increase in use there has been a number of highly publicized recalls of a significant number of those devices.
The American Red Cross has more on automated external defibrillators.