U.S. Approves Wearable Defibrillator

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 of 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%.

Some people at high risk of cardiac arrest have defibrillators surgically implanted. 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.

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% successful in treating sudden cardiac arrest, compared with a 25% success rate when people call 911 for treatment, FDA officials concluded.