For bradycardia, which medication is indicated to increase heart rate?

Atropine sulfate is indicated for the treatment of bradycardia as it acts as an anticholinergic agent that inhibits the action of acetylcholine at parasympathetic sites in smooth muscle, secretory glands, and the central nervous system. By blocking the effects of the vagus nerve, atropine effectively increases heart rate by allowing the heart's intrinsic pacemakers to become more dominant, thereby overriding the slow heart rate associated with bradycardia.

This mechanism is crucial in clinical settings where bradycardia may lead to decreased cardiac output and subsequent symptoms. Atropine is often administered in emergency situations, such as during advanced cardiac life support (ACLS) protocols, specifically for symptomatic bradycardia.

Other medications listed do not have the same effect on heart rate in this context. For instance, ipratropium is primarily used as a bronchodilator and does not significantly impact heart rate. Diltiazem is a calcium channel blocker that can actually slow the heart rate further and is typically used to treat hypertension or certain types of tachyarrhythmias. Amiodarone is an antiarrhythmic that is used in various types of arrhythmias but may not significantly raise the heart rate in