I started getting palpitations and flutters about 4 years ago. Didn’t know why and cardiologist said nothing wrong. Then I tried carnivore by accident when I first started keto and didn’t put it together that it got worse. I had tachycardia, heart palpitations and flutters that’s drove me nuts for a long time. Eventually added in lots of spinach, avocado, broccoli and cauliflower (I probably total >500g of all that) and problem solved. I don’t think it’s just the potassium because I’ll still get some heart pounding after eating a whole potato. Something about those veggies...
Just curious, were you eating organ meats at the time?