What is the effect of beta-adrenergic blockers on heart rate?

Beta-adrenergic blockers, also known as beta-blockers, primarily function by blocking the action of adrenaline on beta-adrenergic receptors, which are found in the heart and other tissues. When these receptors are inhibited, there is a reduction in the heart's response to sympathetic nervous system stimulation. This results in a decrease in heart rate, primarily because the blockers prevent the usual increase in heart rate that occurs during stress or physical activity.

By mitigating the influence of adrenaline, beta-blockers can lead to lower heart rates during both resting and active states. This effect is beneficial in managing various cardiovascular conditions such as hypertension, heart failure, and certain arrhythmias, where controlling heart rate can help reduce the overall workload on the heart and improve blood flow dynamics. Additionally, the ability of beta-blockers to decrease heart rate is one of their key therapeutic benefits, making this choice the correct understanding of their pharmacological action.