Does Taking Vyvanse Cause Dizziness And And High Heart Rate?

I m 16 years old, male, 6 3 , 185 lbs. I have been prescribed Vyvanse to treat my ADD symptoms for about two years (currently at 70mg), and the results have been amazing. I have maintained a 4.0 GPA or higher in every grading period so far in my highschool career. But, I have recently noticed that I often get dizzy while doing cardio workouts, and a dangerously high heart rate. However, I m in no means out of shape, and am extremely ripped. I m worried that Vyvanse is messing with my heart, and I m not sure what to do. I was a 3 sport varsity athlete as a freshman, and this issue is really giving me a scare. I would just stop taking Vyvanse, but it helps me do great in school, and I m getting to the point where I m dependent on the drug. What do I do?