Has anyone else experienced the above. DS (nearly 7) has been on meds for adhd for 12 months which has improved his and our whole families life massively. He had paed check up app and his heart rate was increased, she asked me to get it checked with the GP who also found it to be increased. He's now been referred to a cardiologist at the children's hospital. I'm wondering if this is a medication. Side effect or an unrelated problem.