(CNN) -- Mike Mertz was dead.

Mike Mertz says doesn't remember a thing -- only what people told him later.

With no pulse, no heartbeat and no vital signs, he lay slumped in the front seat of his Saturn, foot wedged against the accelerator with the car stuck between a tree and a stucco wall in Mertz's townhome complex in Glendale, Arizona.

He never saw his life flash before his eyes. In fact, he doesn't remember a thing -- only what people told him later. A UPS driver, Corey Ash, was making deliveries that Wednesday afternoon, when he heard the engine noise.

Sprinting across the street, Ash reached across Mertz's slumped body, turned off the car and pulled the 59-year-old from his vehicle. He hit 911 on his cell phone and started CPR, the way he had learned it in a National Guard training exercise two months earlier.

The American Heart Association says that sudden cardiac arrest kills more than 400,000 people in the United States every year.

This is the worst-case scenario. If a person's heart stops pumping blood through the body, and they aren't in a hospital, they have only about a 2 percent chance of surviving without serious disability. But Arizona cities including Glendale are starting to find that a few simple steps can radically improve the odds.

Less than a minute after his 911 call, Ash could hear the ambulance siren racing from Fire Station 154, barely a mile from the complex. When the truck arrived, a burly medic firefighter named Ruben Florez thumped an urgent rhythm on Mertz's chest, 200 times in the next two minutes, before another medic stepped in and delivered an electric shock from the paddles of a defibrillator. After 600 chest compressions and three electric shocks, a weak pulse returned.

Until three years ago, Arizona's success rate in cases like this was no better than most of the country. This past month, however, physicians in the state reported in the Journal of the American Medical Association that a new regimen by paramedics has tripled the success rate, to more than 5 percent. Among patients whose collapse from cardiac arrest was observed, long-term survival went from 4.7 percent to 17.6 percent.

In a bold departure from standard practice, paramedics in most Arizona cities do not follow the guidance of the American Heart Association. Instead, they follow a protocol that was developed at the University of Arizona's Sarver Heart Center, largely by Dr. Gordon Ewy.

Even after cardiac arrest, Ewy said, there's enough oxygen in the body to feed the brain and keep a person alive for several minutes. But that air helps only if someone compresses the heart to circulate blood. In traditional CPR, rescuers alternate 30 chest compressions with two long "rescue breaths." Paramedics are trained to start by checking the airway, and insert a breathing tube at the start of resuscitation. These extra steps, said Ewy, waste precious time.

In Arizona, paramedics skip the breathing step when they begin to treat a cardiac arrest. They simply alternate two minutes of pumping on the chest -- 200 compressions -- with a single shock from a defibrillator.

Health Library MayoClinic.com: CPR

Epinephrine, a powerful stimulant that jump-starts the body's vital systems, is given as soon as possible. Paramedics insert a breathing tube only if several cycles of shock and compressions fail to re-start the heart.

Ewy said the Arizona study, along with studies on bystander interventions in Japan and his own animal research, show that resuscitation without additional breathing is superior.

"In my mind, the evidence is overwhelming right now," he said.

On Monday, just weeks after the Arizona study was published, the AHA revised its official guidelines to promote breathless resuscitation as the preferred method for bystanders without CPR training -- even as it continues to recommend medical professionals such as EMTs continue to incorporate artificial breaths.

Dr. Vinay Nadkarni, past chairman of the American Heart Association's Emergency Cardiovascular Care Committee, said it is too soon to say whether Arizona's EMT method is better than the AHA guidelines. He noted that while Arizona paramedics don't stop to give breaths, they do insert a device to keep the airway open. He said the AHA agrees that forceful, "minimally interrupted compressions" are the most important factor in resuscitation.

But Nadkarni said the AHA is committed to what works. "If there is a way to save lives, and a system can find a way to save a life, the Heart Association is for it."

Crystal Sorenson, a Glendale firefighter and medic for more than 20 years, experienced a vivid example last summer with the case of 48-year-old Daniel Lane. As she pounded his chest, Lane kept grabbing her wrist, struggling to look up. Each time she paused to deliver a defibrillator shock, "he'd let go and drop down, passing out."

A similar story inspired Ewy, who told CNN about a recording of a 911 call he heard several years ago, on which dispatchers guided a woman through CPR on her husband while she waited for paramedics to arrive.

"After a while, she came back to the phone and said, 'Why is it every time I press on his chest, he opens his eyes, and every time I stop and breathe for him, he goes back to sleep?' " Ewy paused and gave a rueful laugh. "This woman in 10 minutes learned more about cerebral perfusion [getting blood flow to the brain] than we had in 15 or 20 years of CPR research."

All that research, Ewy said, pointed to one thing: "You don't stop pressing on the chest for anything."

In Glendale, paramedics are convinced they have a good thing going. "I hate to say it, but before, you went in [to a cardiac arrest scene], almost expecting that it wouldn't work," paramedic Matt Juscius said. "Now... it's almost commonplace to have these guys come down to the station."

Mike Mertz had a big grin on his face last week, walking in to shake hands with Florez and the rest of the crew at station 154. Outside, he shook his head at what might have been.

"I was completely out. Gone." Now, aside from still-sore ribs and a new implanted defibrillator, he's fine. "If that UPS guy didn't come around the corner, I wouldn't be here today. It was that close." E-mail to a friend

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