I had a cardiac arrythmia and first thing the ER doc asked when they realized I was telling the truth that I wasn't doing drugs (from lab results) was if I drank energy drinks. Yea, with vodka.
"Are you stupid? Don't do that."
Truth is, there's so many variables in play in the modern world who knows. My grandfather also had an arrythmia, so could be genetic. Energy drinks could have contributed. A random virus could have caused it (pre-COVID).
I have friends that have been taking legal meth (adderall) for years, I'm sure that isn't good for cardiac health in the long run either.