CLEVELAND -- Sudden cardiac death claims 300,000 lives in the United States every year, but there is a new way to prevent it.

NewsChannel5 reports that doctors at MetroHealth Medical Center are leading a major international study aimed at identifying those most at risk.

A light walk on the treadmill gives doctors detailed information about Denise Chambers' heart. They're looking for tiny irregularities in the electrical pattern, called T-wave alternans.

"When the pattern becomes irregular or starts to alternate from beat to beat, then that leads to electrical instability in the heart and cardiac arrythmias," Dr. David Rosenbaum of MetroHealth said.

T-wave alternans are found in 70 percent to 80 percent of patients at high risk for sudden cardiac death. The problem is that they don't show up well on standard EKGs.

So Rosenbaum and his colleague, Dr. Otto Constantini, found a way to catch them.

"The test is performed as a standard low level stress test; it's a very simple exercise stress test," Rosenbaum said.

The information gathered during the stress test is then fed into a complicated computer formula. What comes out is a much closer look at the heart's electrical patterns.

"If a patient tests positive for T-wave alternans, then they should have definitive therapy with an implantable defibrillator in much the same way that Dick Cheney did several weeks ago," Rosenbaum said.

After a mild heart attack and irregular heartbeats landed her in the emergency room, Faith Brinkley was anxious to join the study.

"It was kind of scary living like that -- not knowing whether I was going to get an irregular heartbeat and not pull through (or) go to sleep and not wake up," she said.

Brinkley tested positive for T-wave alternans, and doctors at MetroHealth implanted a defibrilator last month.

"At least I know it's going to help me to be here another 10 or 20 years," she said.

The only other test available to measure T-wave alternans is an invasive procedure that can be risky and that isn't 100 percent accurate.

MetroHealth is looking for more volunteers to enroll in the study. For more information, call (216) 778-ABCD.