There are no amino acids (thus no proteins) that I am aware of that contain either potassium or chloride.

However, amino acids (and thus, proteins) are typically polar, and can have regions that are slightly electronegative or slightly electro positive (or both).

Potassium ions are positive, and chloride ions are negative, so the possibility exists that these ions “stick” to the spike protein in solution, like magnets. However, it wouldn’t be a very strong bond. Consider that all the proteins in our blood have slightly negative and slightly positive regions, so I doubt that would be the case, but I suppose it is possible.

If your concern is that the spike proteins are custom made with bond with KCl (like how hemoglobin is custom made to attract oxygen via its iron atom), the real concern would be it depleting potassium ions from our blood (which our hearts need to function), not additional potassium being added.

So again, there is simply no reason to be concerned with the KCl in the shots from what I see.

The myocardial issues have more likely been due to inflammation (a foreign protein our body does not recognize), and its associated issues (blood pressure increase, arterial wall damage, and excess cholesterol production).