Most of the athletes who die are college or high school students who suffer cardiac arrests triggered by heart disease nobody knew about until the accident.

While current guidelines recommend a physical exam and a medical history before participating in college sports, some doctors believe measurements of the heart's electrical activity -- known as an electrocardiogram, or ECG -- should also be required.

Two independent U.S. studies, both published in the Annals of Internal Medicine, now show that this extra measure allows doctors to identify twice as many at-risk athletes in a cost-effective way.

We spend a lot of money trying to design treatment for people late in life, cardiologist Dr. Aaron Baggish, who worked on one of the studies, told Reuters Health. This is a chance to make a difference in young people.

Over three years, Baggish, of Massachusetts General Hospital, Boston, and his colleagues screened 510 Harvard students with ECG.

Most heart problems show up as abnormal activity, but not all. So to vet the results, the researchers also did an ultrasound scan, considered the gold standard for detecting heart problems, though considerably more expensive than the

ECG.

From the ultrasound, it turned out that 11 of the athletes had heart disease. Three of them had conditions serious enough to restrict sports participation, including a thickening of the heart muscle that can lead to heart-rhythm disturbances and cardiac arrest - in which the heart stops beating suddenly.

Using ECG in addition to medical history and physical examination, doctors picked up 10 of the 11 cases, including the three serious ones.

When limited to standard screening, however, they registered only five of the cases, missing two of the serious ones.

ECG is an extraordinary tool to detect risk in patients, said Dr. Gaetano Thiene, a cardiologist at the University of Padua in Italy, who was not involved in the study.

Italy introduced mandatory screening of all young athletes in the early 1980s, and since then sudden deaths have dropped ten-fold, from 4 to 0.4 per 100,000 athletes each year. In the US, the rate has been estimated at about 1 in 100,000.

When the cardiologist discovers a potential problem in the ECG, the doctor goes on to do an ultrasound. If there is serious heart disease, the athlete may be disqualified from sports other than low-intensity disciplines such as golf.

In Baggish's study, one in six athletes who were tested turned out to be a false positive. While this number may seem prohibitively high, Baggish said the ECG criteria are based on average people and need to be refined for use in athletes.

Baggish said the study was not designed to change public policy, although his personal preference would be for teams that are already doing screenings to consider this.

This is a rare phenomenon, he said, but when it occurs it's catastrophic.

Adding ECG to the standard screening would cost $89 per athlete, Stanford researchers found in a cost-effectiveness analysis.

The cost per participant is pretty reasonable -- less than the cost of a good pair of athletic shoes! Dr. Mark Hlatky of Stanford University, who worked on the study, told Reuters Health in an e-mail.

Other experts said ECG-based screening was not an option in the US at this point. Lack of resources, including too few cardiologists, makes it a far more complex venture than it might seem initially, wrote Dr. Barry Maron of the Minneapolis Heart Institute Foundation in an editorial accompanying the new reports.

Medicine