Not for me, I literally don’t notice it unless I know it’s happening right now and “listen” for it.

But I’ve been told by other patients that they feel it as light-headedness or dizziness, may feel their heart pounding or like they can’t breath, or like the heart/body skips a step, and if the arrhythmia exacerbates to fibrillation, people lose consciousness very quickly (and may or may not die if untreated). Maybe that translates to your experience, but I don’t know. Generally it’s described more as a continuous feeling for some time, from a couple of seconds up to hours. But it varies a lot. ECG monitoring helps there.

But my specific arrhythmia were also found quite a long time ago, by chance during a standard exam for sports competition fitness as a child. So for pretty much my whole life I’ve been barred from stimulant and basically psychopharmaceutical medication of any kind, since pretty much all of them can cause or exacerbate heart conditions.

Seeing as I totally don’t notice episodes, a scenario where someone didn’t go to that exam and unsuspectingly walks around with that same or similar heart condition completely untreated, and kills themself by self-medicating and slipping into fibrillation is totally possible.

That said, it’s also not a very wide-spread condition, just a rare possibility. Still, please continue to advocate for yourself to have that checked out!

(Edited for an attempt at brevity)