WASHINGTON (AP) _ The government has approved the first wearable defibrillator, one people strap on under their clothes to zap their hearts out of lethal irregular rhythms _ possibly helping 50,000 patients a year.
The Lifecor Wearable Cardioverter Defibrillator is intended for people at risk of dying from sudden cardiac arrest while they are awaiting a heart transplant or right after they survive a heart attack.
About 250,000 Americans die each year of cardiac arrest, which occurs when the heart suddenly quits pumping in an organized way, stopping blood circulation.
Unless victims are quickly revived by an electrical shock to the heart, they soon die or suffer irreversible brain damage. For each minute that passes before a defibrillator shocks the heart back into a normal rhythm, the chance of surviving drops 10 percent.
Some people at high risk of cardiac arrest have defibrillators surgically implanted in their chests. Others survive thanks to portable external defibrillators that bystanders can use when they collapse.
The Food and Drug Administration approved Lifecor's wearable version Tuesday as an alternative to portable defibrillation for people who need only temporary help _ while they're awaiting a transplant or until their heart recovers after a heart attack.
``It's user-friendly,'' said FDA cardiovascular device chief Dr. Bram Zuckerman. ``It might have a significant impact,'' helping 50,000 recovering heart-attack patients and another 1,000 people awaiting a new heart each year.
The device resembles a fabric gun holster, strapped to the lower chest and over the shoulders. Four sensors measure heartbeat. They are wired to a battery-operated tiny defibrillator worn on the belt that sends a shock back to the heart when the sensors measure a lethal irregular heartbeat.
In clinical trials, 289 heart patients in the United States and Europe wore the defibrillator 20 hours a day for three months. It was 71 percent successful in treating sudden cardiac arrest, compared to a 25 percent success rate when people call 911 for treatment, FDA officials concluded.
The device failed to successfully treat two episodes of cardiac arrest because patients had incorrectly assembled the electrodes, but Lifecor subsequently changed the design to eliminate confusion, FDA said.
Some 2 percent of patients experienced an unnecessary shock from the device, a rate similar to implantable defibrillators. The most frequent side effect was a temporary skin rash experienced by 5 percent of defibrillator wearers.
The new defibrillator will be available early next year but only in limited numbers because Pittsburgh-based Lifecor is redesigning it to be even smaller, said vice president Kathy Higgs. Because patients will need it only temporarily, the company plans to rent it and currently is negotiating rental fees with Medicare and insurance companies, she said.