What is considered the first-line treatment for unstable bradycardia?

In the context of treating unstable bradycardia, atropine is considered the first-line treatment due to its mechanism of action as an anticholinergic agent that increases heart rate by blocking vagal influences on the heart. When a patient exhibits symptoms of instability, such as hypotension, altered mental status, or signs of shock, rapid intervention is crucial. Atropine can be administered quickly and effectively to increase the heart's conduction rate, thereby improving cardiac output.

While transcutaneous pacing is an important alternative for immediate management of unstable bradycardia, especially if atropine is ineffective or if the patient is severely symptomatic, it is not the initial recommendation in most cases. Atropine is generally preferred as a first step before considering other invasive measures.

This makes atropine a key component in the ACLS algorithms for managing bradycardia, as it allows for prompt treatment of the underlying issue without the need for more complex interventions right away.