Children should be screened for heart problems with an electrocardiogram before getting drugs like Ritalin to treat hyperactivity and attention deficit disorder (ADD), 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 to stay focused and control their behaviour.

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.

2 per cent of children found to have heart problems

An EKG can detect abnormal heart rhythms that can lead to sudden cardiac arrest. Children who are already on ADHD drugs should also be tested, Vetter said. If problems are found, the child should be sent to a pediatric cardiologist. With careful monitoring, Vetter said children with heart problems can take the medicines if needed.

She said a screening of about 1,100 children found that about two per cent of them had some kind of heart problem.

"We thought it was reasonable to include the electrocardiogram as a tool for the pediatrician, the psychiatrist so that this would help identify additional children who have heart disease," Vetter said.

But Dr. Steven Pliszka, a child psychiatrist at the University of Texas in San Antonio, said he was baffled by the EKG recommendation. He said there's no evidence that sudden death is a bigger problem for children taking stimulants than for children who aren't taking the drugs.

Pliszka said an EKG might deter people from seeking treatment because it's an added expense and hassle. Psychiatrists aren't likely to have an EKG machine, and pediatricians might not either, making patients go elsewhere to get the test, he said.

An ADHD advocacy group called CHADD said parents should monitor their child's reaction to all medications. EKG screening "will bring an even further measure of safety to what is already a safe clinical treatment approach," the group said.

The American Academy of Child and Adolescent Psychiatry recently updated its treatment guidelines for ADHD, and did not recommend routine EKGs, said Pliszka, who was the lead author. He has received research support or served as a consultant for makers of ADHD drugs.

"We definitely did not feel we needed to screen everyone," Pliszka said.

He noted that the heart association doesn't recommended EKG screening for young athletes to prevent sudden death. The group has said it wasn't feasible or cost-effective to screen all student athletes.

A spokeswoman for Novartis Pharmaceuticals Corp., which makes Ritalin, said the company had not seen the latest heart association statement and could not comment, but she pointed out that the label does suggest patients be evaluated for heart problems.