In fact, patients whose EKGs showed they'd had a serious heart attack were brought in faster after the city equipped its ambulances and fire trucks with machines to do the test.

Pre-hospital EKGs are recommended by medical groups because they cut the time it takes hospitals to get heart attack patients the care they need, with every minute saving heart tissue.

But some researchers had feared that doing the tests in the field would slow down the paramedics instead, producing no or little net benefit.

"This study shows that out in the real world those concerns were not true," said Dr. Umesh Khot, a cardiologist at the Cleveland Clinic in Ohio, who wrote an editorial about the findings.

The City of San Diego began training paramedics in doing EKGs, or electrocardiograms, after it received a donation of half a million dollars from a heart attack patient.

Until the end of 2005, San Diego emergency medical services had been taking people with chest pain to a hospital of their choice. But since the pre-hospital EKGs were rolled out, patients who test indicated a massive heart attack, called STEMI, have been directed to the nearest hospital that can care for them.

The new study, led by Dr. Ehtisham Mahmud of the University of California, San Diego (UCSD), used data from nearly 22,000 patients evaluated for chest pain before and after the new system was put in place.

On average, paramedics spent only 18 seconds more on the scene after they started doing field EKGs, and the transportation time rose by just 12 seconds.

By comparison, the advance notice saves about 15 to 20 minutes once patients get to the hospital, said Mahmud, whose study appears in the Journal of the American College of Cardiology.

And with the new system, it took considerably less time for STEMI patients, who have completely blocked heart arteries, to reach the hospital.

"The paramedics are getting those patients to the hospital even faster than the rest," Mahmud told Reuters Health. "They were shaving off about three minutes."

He added that for every additional 15 minutes a heart attack patient goes without treatment, one in 100 will die - so although three minutes isn't a lot, it could still be meaningful, according to Mahmud.

Pre-hospital EKGs have now been rolled out across San Diego County, and the Cleveland Clinic's Khot said most other places in the U.S. have adopted it as well.

Mahmud said death rates from heart attacks have dropped from between six and seven percent to less than four percent at UCSD over recent years, although it's hard to pinpoint the exact reasons. While medical treatments have been refined, he ventured, "this is more a system-of-care thing."

Khot praised the study for looking at the whole picture instead of just focusing on the faster treatment once patients reach the hospital.

"This is part of making sure there are no untoward effects" of the new system, he said.

SOURCE: bit.ly/MIhoDS Journal of the American College of Cardiology, online July 25, 2012.

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