I had the event where I got shocked seven times in a row, and it started a series of panic attacks, which led me to what I thought was a solution (the benzo). Of course now I know better. I have a genetic mutation that affects the main cardiac sodium channel and causes arrhythmias. My dad died in his sleep at 42 from a fatal rhythm, which led to cardiac arrest. That's why I investigated my own arrhythmias, saw an electrophysiologist, had an ablation, and ended up with the ICD implanted.
For sure, our guts do a lot more than we give them credit for, and we wonder why eating crap food all the time maybe isn't the greatest idea. Obviously in benzo withdrawal, we've probably started eating a little better if we didn't already. Histamine may play a role in some arrhythmias. I really don't know. Many varied things can cause them.