Government advisors say defibrillators, machines that jump-start a stopped heart, may not need to be sold with a doctor's prescription. Philips Medical Systems has asked the Food and Drug Administration to allow over-the-counter sales of its HeartStart home defibrillator. There's no proof yet that in-home use of the machines actually saves lives, though studies show they can be useful in public places like airports. Roughly 80 percent of cardiac arrests happen in the home, and that's where many cardiologists question the usefulness of the two-thousand dollar machines. Still, the FDA asked its scientific advisers to debate the issue. Their general consensus was that getting a prescription for the easy-to-use devices didn't add much value. The FDA isn't bound by the panel's advice, but generally follows it. Every year, about 220-thousand Americans die of cardiac arrest.