For which bradyarrhythmias is atropine effective and when does it fail?

Atropine effective: sinus bradycardia, sinus node dysfunction, vagally mediated (e.g., Bezold-Jarisch reflex), 1st degree and Mobitz I (Wenckebach) AV block. Atropine generally ineffective: Mobitz II AV block and 3rd degree AV block (infranodal) - may paradoxically worsen block by increasing sinus rate without improving conduction. Use TCP or epinephrine for high-degree AV block.

What atropine doses are used for symptomatic bradycardia?

Adult: 0.5 mg IV, repeat every 3 to 5 minutes. Maximum total: 3 mg (vagal blockade complete). Minimum: 0.5 mg (lower doses may cause paradoxical bradycardia from central vagal stimulation). For hemodynamically unstable bradycardia unresponsive to atropine: transcutaneous pacing first-line, then dopamine or epinephrine infusion while preparing for TCP/TVP.

Atropine Bradycardia Response Probability Calculator

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Frequently Asked Questions

For which bradyarrhythmias is atropine effective and when does it fail?

What atropine doses are used for symptomatic bradycardia?