The Federal Aviation Administration has ordered US airlines to begin carrying emergency equipment to help passengers who suffer heart attacks while traveling. US airlines will have three years to put defibrillators on all domestic and international flights. Flight attendants will be taught how to use the devices to get a stricken passenger's heart beating normally.

"The availability of a defibrillator is a life-and-death matter for someone suffering cardiac arrest," said Richard Hamburg, director of government relations for the American Heart Association. "If you're up in a plane, and you don't have a medical kit that has a defibrillator, and you don't have personnel trained, that's almost a death sentence."

The new FAA rules issued Thursday also require airline medical kits, which now contain drugs for patients in insulin shock or suffering from allergic reactions, to contain antihistamine, aspirin and inhalers.

Automated external defibrillators are the size of a toaster and weigh about 4 pounds (2 kilograms). Designed to treat ventricular fibrillation, the most common cause of sudden cardiac arrest, the machines use electric shocks to try to get the heart to resume beating normally.

Ventricular fibrillation kills about 225,000 people each year, according to American Heart Association estimates. Hamburg said chances of survival drop by 10 percent for each minute that a person in cardiac arrest fails to receive treatment.