The Food and Drug Administration is recommending stricter testing requirements for heart-zapping defibrillators after years of increasing problems with the emergency medical devices.

Under the agency's proposal posted online Friday, makers of external defibrillators would need to submit more data and undergo manufacturing inspections before launching a new product.

The tighter regulation is aimed at curbing design and manufacturing flaws with the devices, which are found everywhere from hospitals to schools to airports. The changes would not apply to implantable defibrillators, which are pacemaker-like devices given to patients with heart problems.

Next Tuesday the FDA will ask an expert panel to weigh in on its recommendations. The agency is not required to follow their advice.

Currently, makers of defibrillators are only subject to inspection if the FDA has cause to suspect a problem. Companies including Philips Healthcare and Cardiac Science Corp. have petitioned the FDA to keep their devices approved at this standard.

But the FDA says defibrillator makers have failed to fix problems that have led to the recall of hundreds of thousands of devices.

In 2009, the FDA issued 17 mass recalls on the devices, up from nine in 2005. And more than 28,000 problems have been reported to the agency in the last five years.

Defibrillators use electric shocks to jolt the heart back to normal after patients collapse from cardiac arrest.

External defibrillators generally include two plastic pads that attach to the patient's chest and detect whether the heart is suffering an abnormal heart rhythm. If the problem can be corrected — which is the case about one-fourth of the time — the pads deliver an electric shock that resets the heart's pumping action.

Nearly 300,000 people in the U.S. collapse each year from cardiac arrest, according to the FDA. Academics estimate nearly 500 lives are saved each year in the U.S. as a result of bystanders using external defibrillators.