BOSTON (Reuters) - Destroying a small part of the heart with radio waves can dramatically cut the risk of developing a fatal heartbeat in young adults with a special type of heart rhythm, even if they have no symptoms, Italian researchers reported on Wednesday.

The rhythm problem, known as Wolff-Parkinson-White syndrome, is caused by extra wiring in the heart. As a result, signals telling the heart to beat may get to the main chambers too soon, which can occasionally lead to sudden death. The problem exists in about one in 500 people, but it rarely causes death. Each year, only one out of every 1,000 sufferers dies as a result. Many others experience dizziness, fainting or chest palpitations -- symptoms that can show up as early as age 11.

Doctors already use radio waves, fired from a tiny catheter positioned inside the heart, to destroy the extra wiring. But the operation is not routinely done, in part because doctors try to use medication to prevent the problem.

The new study, published in the New England Journal of Medicine (news - web sites), found that the radio wave technique, known as radiofrequency ablation, benefits many people with no symptoms. Over a five-year period, only two of the 37 patients who received the treatment developed a serious rhythm problem compared to 21 out of the 35 who received no treatment.

The team of doctors, led by Carlo Pappone of the San Raffaele University Hospital in Milan, said young adults with Wolff-Parkinson-White syndrome whose abnormal rhythm can be induced during a special test should receive treatment with radio waves.