Great question! I am not sure of the answer (I couldn't find supporting evidence in the literature) but here's my thoughts on this: Contractility is done majorly by Actin-myosin interaction with ignition (initiation) by Calcium from Sarcoplasmic reticulum ... etc. The active movement is ATP-dependant (and Mg also) and there's no role for potassium. Even the gap junctions between myocytes aren't potassium-dependant. It's mostly the depolarization, which in turn activates the myocytes that is hindered in hyperkalemia. 😊 I hope I could clarify it well.
