Obese children show early signs of heart disease, according to researchers at the Washington University School of Medicine.

A team analyzed 168 children ages 10 to 18 who had heart troubles such as murmurs, pain, acid reflux or high cholesterol. Thirty-three patients -- almost 20 percent -- were considered obese, and 20 -- about 12 percent -- were considered at risk for obesity.

The researchers used an imaging technique that tracks movement of heart muscles.

They found that as a child's body-mass index increases, the heart was more likely to show changes in how the heart moves. The same thing had been seen in obese adults, but it had been assumed this was from long-time strain.

The researchers said the finding may allow doctors to intervene more effectively with overweight children.

"Based on this study, these subtle markers can help us predict who could be at risk for heart disease and heart attacks," said Dr. Angela Sharkey.

Nineteen percent of children 6 to 11 years old and 17 percent of those 12 to 19 are overweight, according to the Centers for Disease Control and Prevention.

The study was published in the Winter 2007 issue of the Journal of Cardiometabolic Syndrome.