Dear Suzy,
The first thing that comes to mind here is that there seems to be a disconnect in the communication between your cardiologist and you. You should be able to walk out of your doctor’s office comfortable with what the evaluation and the plan is for your child’s care, and have all of your questions answered. I will say that without personally evaluating your son and his information, I cannot say what exactly he is experiencing. I can also say that the test results that you have need to be interpreted in light of what is going on with your son’s symptoms. It very well may be that your son’s symptoms may match up exactly with what is found on these tests, or they may have nothing to do with these findings and the findings are coincidental.
At this point, I would recommend adequate hydration for your son, to include four 8-12 ounce glasses of fluid/day, a salty snack, no skipping meals, and no caffeine. This is a frequent cause of these symptoms in the adolescent age group, and an easy fix. However, if this does not improve these problems, I would either go back to your cardiologist and try to get a better explanation or consider a second opinion.