Sodium is the primary electrolyte to supplement. It seems to be lowest in your list,..

The same thing was happening to me I figured out that my body was sending out alarms for low sugar so I added about a tablespoon of honey and after a few days it went away...I read about hypoglycemia and how low blood glucose can cause heart palpitations I’m not a diabetic but now I’m aware that when it happens I need to grab a little something to bring sugar up and the heart flutters go away.. I also bought a glucose starter kit just to check blood sugar levels to keep track it’s good to know even though I’m not a diabetic

I would be very cautious taking potassium supplements - especially at 1000mg. Too much or too little potassium can be impact your heart. Have your doctor specifically check your potassium levels - you may be too high.

You guys are right to warn of being careful in taking potassium. My daughter tests chronically low so she takes a prescription potassium supplement and it’s only 99mg. This is with a blood test verifying the need.
It’s definitely not good to be low but it’s equally dangerous if not more so to potentially take too much.

avocados, egg yolks, oysters, and sardines.
these four items give you your vitamin and minerals.
a book could be written on each one.
Avocados are the potassium source. They are considered a free food because the fiber almost equals the carbs but that does not mean you eat tons of them. Some experts say 1/2 is great; other experts say one avocado is fine.
Egg yolk has choline and sulfur, which heals almost everything. Egg yolk is a natural vitamin-mineral supplement. Do not worry about the cholesterol of egg yolk. The body adjusts. Yolks have vitamins A, D, E, K, and minerals calcium, magnesium, iron, potassium, sodium, and selenium. Yolk choline -- help to regulate cardiovascular function.
Oysters do have carbs. A can is almost 8 carbs but they do not seem to act like veggie carbs. Oysters are full of minerals like zinc, potassium, and magnesium. Oysters fix heart problems.
Sardines with bones have every known and unknown mineral and is a source of quality omega-3 fatty acids which fixes the heart. My cheapest source is the trader joes brand.
Last item: Make sure you only breathe through your nose. Mouth breathing is the root of many illnesses.
Many people have been cured of extreme illnesses just by switching to nose only breathing.

Please do not make a bunch of comments on this. Let it be as it is.
The lady asked for advice; this is mine to her.
Put your advice as your own response.

Never thought to put sardines in Caesar dressing. I use anchovies.

I had severe hart palpitations for 3 years (not related to Keto) - the were called PVCs. (Premature Ventricular Contractions). They drove me crazy and my cardiologist didn't have a good non-invasive solution. At his recommendation, I finally had an endoscopy done of my stomach and esophagus and found that I had acid reflux bad enough to cause ulcers. I never experienced heart burn, so this was a surprise. When I got the acid reflux under control the palpitations stopped. Seems the acid was triggering the Vegas nerve, which lies right up against the heart, thus causing the PVCs. If you are having any kind of heart burn or acid reflux along with your palpatations, try getting that under control and see if it helps.

Kaucar has it improved after stopping the potassium supplement?