Cardiopulmonary resuscitation is crucial when people collapse with cardiac arrest, but it's hard to perform correctly.
High-tech machines that promise to help are already showing up in ambulances and offices. It's not yet proven whether the new technology - like a chest-squeezing gadget or sensors that coax rescuers to pound harder - will improve the 40-year-old resuscitation technique and save lives.
Emergency-care specialists agree that CPR today doesn't save as many lives as it could.
"We've got our work cut out for us to make sure CPR is done better," says Mary Fran Hazinski of the American Heart Association, which is finalizing new recommendations designed to do just that.
More than 300,000 Americans each year die of cardiac arrest, where the heart's electrical system goes haywire and the heart abruptly stops beating, The Associated Press reports.
Portable defibrillators can increase survival, delivering a jolt of electricity that stuns the heart, ending the abnormal rhythm and giving it a chance to resume a normal beat.
But the heart-zappers alone aren't enough. Virtually all cardiac-arrest victims need CPR, too. It buys time until a defibrillator arrives. Often, it's needed immediately after zapping, as the heart struggles to resume circulation.
