Stimulants can raise your heart rate. If you raise it high enough, it can cause a heart attack. There are certain medication combinations that can increase this, such as SSRIs, dopamine agonists like Wellbutrin.
Stimulants are like meth, or if you want a prescription possibly adderall or Ritalin. It's very easy to get a prescription of adderall or buy off the black market, just take like 5x the dose prescribed with some SSRIs or Wellbutrin or tricyclic antidepressants. Even better go for a run or anything cardio and you're basically guaranteed a really high heart rate.
There aren't many cases of people who die by taking even high doses of stimulants (like meth) but it can definitely happen if you're actually trying.
Edit: also snorting the stimulants as opposed to taking them orally will probably increase the effect.