How can hyperkalemia affect cardiac function?

Hyperkalemia, or elevated levels of potassium in the blood, can significantly affect cardiac function due to the role potassium plays in electrical conduction in the heart. With high potassium levels, the resting membrane potential of cardiac cells is altered, which can lead to disturbances in the normal rhythm of the heart.

When potassium levels increase, it can cause an increase in the excitability of the heart's cells, leading to arrhythmias, which are abnormal heart rhythms. These arrhythmias can manifest as palpitations, tachycardia (rapid heart rate), or even bradycardia (slow heart rate) depending on the severity and nature of the disturbance. In extreme cases, severe hyperkalemia can lead to ventricular fibrillation or asystole, resulting in cardiac arrest.

The impact of hyperkalemia on cardiac function is critical in clinical settings, especially for individuals with existing heart conditions or those undergoing dialysis, where potassium levels can fluctuate. Understanding this mechanism is key to preventing serious complications associated with hyperkalemia.