What is the role of potassium in cardiac function?

Potassium plays a crucial role in cardiac function primarily by maintaining myocardial contractility. In the heart, potassium ions are essential for the proper functioning of cardiomyocytes (heart muscle cells). They are involved in the generation and conduction of electrical impulses that regulate the heart's rhythm and contractility.

When the levels of potassium are within the normal range, they help maintain the resting membrane potential of cardiac cells, facilitating the repolarization process after each cardiac cycle. This proper repolarization is vital for the heart's ability to contract effectively and pump blood efficiently.

In situations where potassium levels are abnormally high or low, such as in hyperkalemia or hypokalemia, there can be significant disruptions in cardiac electrical activity, potentially leading to arrhythmias or decreased myocardial contractility. Therefore, maintaining optimal potassium levels is essential for sustaining normal heart function and ensuring effective cardiac output.