New York ? Children should be screened for heart problems with an electrocardiogram before getting drugs like Ritalin to treat hyperactivity and attention-deficit disorder, the American Heart Association recommended Monday.

Stimulant drugs can increase blood pressure and heart rate. For most children, that isn’t a problem. But in those with heart conditions, it could make them more vulnerable to sudden cardiac arrest – an erratic heartbeat that causes the heart to stop pumping blood through the body – and other heart problems.

About 2.5 million American children and 1.5 million adults take medication for attention-deficit hyperactivity disorder, or ADHD, according to government estimates. Stimulant drugs, like Ritalin, Adderall and Concerta, help children with ADHD stay focused and control their behavior.

The medications already carry warnings of possible heart risks in those with heart defects or other heart problems, which some critics said were driven more by concerns of overuse of the drugs than their safety.

The heart group is now recommending a thorough exam, including a family history and an EKG, before children are put on the drugs to make sure that they don’t have any undiagnosed heart issues.

“We don’t want to keep children who have this from being treated. We want to do it as safely as possible,” said Dr. Victoria Vetter, a pediatric cardiologist at the University of Pennsylvania School of Medicine and head of the committee making the recommendation.

The label warnings were added after a review by the Food and Drug Administration of its databases found reports of 19 sudden deaths in children treated with ADHD drugs and 26 reports of other problems including strokes and fast heart rates between 1999 and 2003. There were also reports of heart problems in adults; the committee didn’t look at adults.