What is a potential effect of excessive potassium on the heart's function?

Excessive potassium in the blood, a condition known as hyperkalemia, can significantly alter the electrical activity of cardiac muscle cells. One of the primary effects of increased potassium levels is the disruption of the resting membrane potential of these cells, which can lead to changes in the heart's rhythm. High potassium levels can impair the normal repolarization process during the cardiac cycle, resulting in an arrhythmic heartbeat. This means that the heart may beat irregularly or even stop beating altogether in severe cases.

In contrast, while increased rest potential, enhanced depolarization, and cardiac hypertrophy reference aspects of heart function, they do not directly describe the immediate consequences associated with excessive potassium levels. Therefore, the potential for an arrhythmic heartbeat stands out as the specific and critical effect of hyperkalemia on heart function.