Hyperkalemia! Please Read

My mother was diagnosed with Hyperkalemia. I know her adrenals are weak just like mine however she doesn't have a doctor that believes in adrenal fatigue. They have not assessed what is causing this as of yet, however they are doing test. Is there anything that is low in potassium that she could take naturally or medically that could help keep her heart stronger and beat normally until, Lord willing, they find a way to help her?