What is the impact of potassium on heart function?

Potassium plays a vital role in maintaining normal heart rhythm, which is why the correct choice highlights its critical function in this process. This mineral is essential for the proper conduction of electrical impulses throughout the heart. It helps regulate the balance of excitability and contractility of cardiac muscle cells.

When potassium levels are within the appropriate range, they support the repolarization phase of cardiac action potentials. This is crucial for ensuring that the heart beats in a coordinated and rhythmic manner. An imbalance, such as hypokalemia (low potassium levels) or hyperkalemia (high potassium levels), can lead to arrhythmias, which are disturbances in heart rhythm that can be serious or even life-threatening.

Other choices provided do not accurately portray potassium's primary function in heart health. While potassium can influence heart rate, particularly in cases of imbalance, the core aspect to note is its integral role in maintaining a stable and regular heartbeat. Therefore, understanding potassium's function in the context of cardiac physiology underscores why it is deemed critical for normal heart rhythm.