i think you have nailed it, CS.
there are certain key conditions that can exacerbate this heart action.
first is the kidneys themselves. kidney function in the general population is not good and varies greatly from person to person. things like that stuff from china - melamine i think its called - just destroys the kidneys. so does mercury.
second is the effect on hormones, or the lack thereof.
third is one of primary concern to me in most folks - oxygen and water. people are not oxygenated. supplement it until you find out what its like to have enough oxygen. people are not hydrated - this takes a lot of effort for some. it sounds simple, people drink water. they even take the salt. they are still not hydrated. nothing works right without proper hydration. take all of anything you want, it wont work right. may not work at all. could make things worse. make it a goal to get hydrated in 30 days. it may take that long or longer to figure it out.
also, a quick fix is a potassium supplement, as long as not on blood pressure meds.