What cardiovascular effect does atropine typically have?

Atropine is an anticholinergic medication that primarily blocks the action of acetylcholine at muscarinic receptors. In the context of the cardiovascular system, its most well-known effect is to increase heart rate. This occurs because atropine inhibits the parasympathetic influence on the heart, which normally acts to slow the heart rate via the vagus nerve. By blocking this parasympathetic activity, atropine allows for unopposed sympathetic activity, thereby leading to an increase in heart rate.

This effect is particularly useful in clinical settings, such as in cases of bradycardia, where the heart rate is abnormally low. Administering atropine helps to raise the heart rate to a more acceptable level. In summary, the increase in heart rate induced by atropine is a direct result of its anticholinergic action and the resultant reduction in parasympathetic tone on the heart.