Cardiologist Referral After Vyvanse | ADHD Information

Hi everyone,

My 6 year old son was diagnosed at the beginning of summer with ADHD.  We started on Concerta 18mg, but he was moody, flat, depressed--didn't want to leave the house, didn't want to play, didn't smile.  It was awful.  We took him off after almost three weeks.  Then, we moved to Vyvanse.  Thirty minutes after his first dose, he said he felt tingly, and then a few minutes later he said he felt shaky.  He sat on the couch under a blanket, whimpering and rocking back and forth, and said he felt scared.  I was so frightened!  The change in him was so dramatic and intense, and it was a long day of crying and moodiness. He fell asleep around 5pm (he hasn't napped in 4 years), woke up at 5:30pm and then he finally smiled again for the first time since taking the med at 5:43pm!  I think he was as relieved as we were! 

So, I told our pediatric neurologist this, and she wants him seen by a cardiologist before she will try him on another med.  Personally, I am so burned on the meds right now, I don't know what to think.  But my question is...what are we looking for at the cardiologist?  Arrhythmia?  Some sort of pre-existing condition that would not allow him to be on the stimulants?  Does his reaction to the Vyvanse sound like some sort of cardiac problem?  Or is she just making sure that we are safe to proceed?  I am all about the cardiologist appointment--I am happy to go, because I certainly don't want to risk anything, but I am just curious if y'all have any feedback as to what we are looking for/ruling out here.