What effect do beta-blockers have on heart rate?

Beta-blockers primarily function by blocking beta-adrenergic receptors in the heart, which are stimulated by catecholamines like adrenaline. This blockage leads to a reduction in heart rate because it diminishes the effects of the sympathetic nervous system, which typically increases heart rate in response to stress or physical activity.

By inhibiting these receptors, beta-blockers decrease the heart's workload and oxygen demand, making them beneficial in managing conditions such as hypertension, heart failure, and arrhythmias. Patients often experience a reduced heart rate and improved cardiac function as a result of this medication. Additionally, this reduction in heart rate can help alleviate symptoms of heart conditions and improve overall cardiovascular health.

The other options do not accurately reflect the physiological effects of beta-blockers. They do not lead to an increase in heart rate nor simply maintain it; instead, they are specifically aimed at achieving a decrease in heart rate, making the correct answer evident.