Dear katiedevall1 and abbymay16,
Having many pediatric patients with asthma, I have heard a lot of different symptoms that children can describe for asthma--coughing, tightness, shortness of breath, wheezing are certainly the "classic" symptoms, but I completely agree with you Abbymay16 that tightness of the chest can be described as soreness or "heart hurting" for a 6 year old. I've had kids complain that their stomach hurts (and it turns out that it is from coughing all the time). If the asthma symptoms are fully controlled (i.e. he is otherwise fine) and these symptoms are persistent, I would certainly question it being due to asthma and it warrants further evaluation. However, it is also important to look at how he initially presented and how he was diagnosed with the asthma--were his initial symptoms also chest tightness and shortness of breath? Does he appear to be breathing fast/working hard to breathe or wheezing when he complains? Does it get better if you give him his rescue inhaler?
Some kids who have GE Reflux actually can be misdiagnosed with asthma, particularly if they have a chronic cough as a major symptom. If they have heartburn or reflux symptoms, this may also be called "heart hurting" or "cramping." I would trust your instincts (true, sometimes mom does know best) and if this does not seem to be improved with your asthma care plan, then question it. Maybe he is undertreated? You could always get a second opinion or go back to your pediatrician if it was the allergist/pulmonologist who made the diagnosis.
Good Luck!
Michael