Which among the following is considered a negative chronotropic medication?

A negative chronotropic medication is one that decreases the heart rate. Beta-blockers are a class of medications that fall into this category, as they block the effects of adrenaline on the beta-adrenergic receptors in the heart. This action leads to a reduction in heart rate, particularly during stress or physical activity.

In cardiac physiology, managing heart rate is crucial for patients with various cardiovascular conditions. When patients are prescribed beta-blockers, they may experience improved exercise tolerance and decreased myocardial oxygen demand, which can be beneficial in treating conditions like hypertension, angina, or heart failure.

While the other options have their own clinical uses, they do not primarily function to decrease heart rate. ACE inhibitors primarily work by relaxing blood vessels and reducing blood pressure, aspirin is used as an antiplatelet agent to prevent clotting, and diuretics help reduce fluid overload by increasing urine output. None of these actions involve the direct modulation of heart rate in the manner that beta-blockers do.