What are the effects of elevated and decreased blood potassium levels on myocardial cells?

Elevated or reduced blood potassium levels can both stimulate myocardial cells when the change is mild. However, significantly increased or decreased blood potassium levels will suppress myocardial cell activity.

Potassium ions in the blood help maintain normal cellular metabolism and regulate blood osmotic pressure and acid-base balance. Abnormal potassium levels—either too high or too low—can cause damage to myocardial cells. If a patient's blood potassium level is only slightly elevated or reduced, it may mildly stimulate the myocardial cells, potentially causing symptoms such as palpitations or arrhythmias. When blood potassium levels are markedly elevated or reduced, they begin to inhibit myocardial cells, decreasing their excitability, which can also lead to various arrhythmias.

Whether blood potassium levels are too high or too low, they can cause damage to myocardial cells. If any discomfort occurs, prompt medical attention and treatment are recommended to prevent risks to life and health.