Low/No Carb diets and irregular rhythm

Have been on a very low carb diet for the last two weeks, and suddenly this weekend experienced a few PACs every few minutes, heightened today with two occurring in a row every few minutes or so. Seems more prevalent by far when I am resting vs. moving around. Oddly enough, the only two A-fib events I ever experienced (11 and 2 months ago) were both during periods of low carb dieting I was doing. Now I'm starting to think there's something here.

I've done similar diets most of my life, periodically and never have had any issues.

If you aren't "keto-adapted," this can happen. When you drop carbs very low, your insulin levels will drop significantly. Higher insulin levels will signal the kidneys to conserve or retain sodium. Conversely, low insulin levels will signal the kidneys to excrete sodium. This signal can be strong enough that potassium will be excreted, too - to keep the Na/K balance. This can be a primary cause of "low carb flu." The standard advice is to supplement sodium, up to 5g/day. Also potassium & magnesium.

I've been keto adapted since Oct 2009. I did experience an afib episode caused by electrolyte imbalance during the adaptation process (knew a lot less about the electrolyte story and low carb diets then). Subsequently, this has not caused me any issues. I routinely fast 5 consecutive days out of 14 (sometimes 7) and eat a 75% fat calorie diet on days I do eat. My insulin can drop to less than 1 on a fast.

Interesting. I do supplement Magnesium and Potassium, but I never would have thought of doing sodium as well. What would be the recommended amount of Mag and Potassium you would suggest?

Does make sense though, because I went and ate two bags of potato chips and a cookie, and the PACs vanished this afternoon - though I cringed because my diet was wrecked.

Well, you could just try the sodium and see what happens. The advice comes from Phinney & Volek <[www.amazon.com] It may take care of it. I'd start with a couple of grams of salt and work up to what you need.