Hello. I have a six year old daughter. Recently she has been stating that her heart is racing very fast. It doesn't appear to be all the time but the frequency is increasing. She has moments when she goes pale and she will grab her chest and say that her heart is racing. She is autistic and suffers from anxiety however she has started to say this when she appears quite calm and not in stressful situations. I thought they were panic attacks however now I am concerned that it is something else. Her resting heart rate is ranges from 108 -115 however it increases when she states her heart is racing. Should I be concerned?