What class of drugs can cause a significant reduction in heart rate?

Beta blockers are a class of drugs that work primarily by blocking the effects of epinephrine (adrenaline) on beta-adrenergic receptors in the heart. This action leads to a decrease in heart rate and myocardial contractility, resulting in reduced cardiac workload and oxygen demand. Beta blockers are commonly prescribed for conditions such as hypertension, heart failure, and arrhythmias. Their ability to effectively lower heart rate makes them particularly valuable in managing tachycardia and other heart rhythm disorders.

On the other hand, calcium channel blockers primarily affect vascular smooth muscle and cardiac contractility; while some may also lower heart rate, their primary action is not as pronounced as that of beta blockers. ACE inhibitors are primarily focused on the renin-angiotensin-aldosterone system to help manage blood pressure, and they do not directly impact heart rate. Thrombolytics, used to dissolve blood clots, play no role in heart rate reduction either. Therefore, beta blockers are specifically recognized for their significant effect on lowering heart rate among the listed drug classes.