Atropine Use in Bradycardia

Indications and Administration

The American College of Cardiology recommends atropine for symptomatic sinus bradycardia, generally heart rate less than 50 bpm associated with hypotension, ischemia, or escape ventricular arrhythmia, with an initial dose of 0.5 mg IV, which can be repeated every 3-5 minutes to a maximum total dose of 3 mg 1, 2
Atropine is indicated for symptomatic AV block occurring at the AV nodal level, with a recommended initial dose of 0.5 mg IV, which can be repeated every 3-5 minutes to a maximum total dose of 3 mg 1, 2
The American Heart Association recommends atropine for ventricular asystole, with a dose of 0.5 mg IV, which can be repeated every 3-5 minutes to a maximum total dose of 3 mg 2, 3
Atropine is recommended for bradycardia with evidence of hemodynamic compromise, such as hypotension, altered mental status, chest pain, acute heart failure, or shock, with an initial dose of 0.5 mg IV, which can be repeated every 3-5 minutes to a maximum total dose of 3 mg 1, 4

The American College of Cardiology recommends using atropine with caution in patients with acute coronary ischemia or myocardial infarction, as increased heart rate may worsen ischemia or increase infarct size 1, 4
Atropine should be used with caution in patients who have undergone cardiac transplantation, as it may cause paradoxical slowing of heart rate 1, 4
The American Heart Association recommends avoiding atropine in patients with type II second-degree or third-degree AV block with new wide-QRS complex, as the block is likely at the infranodal level 1, 4

The American College of Cardiology recommends considering transcutaneous pacing for unstable patients not responding to atropine 1, 4
The American Heart Association suggests using β-adrenergic support, such as dopamine or epinephrine, as temporizing measures while preparing for transvenous pacing 1, 4

The American College of Cardiology notes that atropine may cause tachycardia, which may worsen ischemia in patients with acute coronary syndrome, and ventricular tachycardia or fibrillation, although rare 3
Atropine may cause central nervous system effects, including hallucinations and fever, with repeated administration 3
The American Heart Association warns that atropine may cause paradoxical worsening of bradycardia with doses less than 0.5 mg 2, 3

The American College of Cardiology recommends an initial atropine dose of 0.5 mg IV push for bradycardia, with repeat dosing of 0.5 mg every 3-5 minutes as needed, up to a maximum total dose of 3 mg 5
The American College of Cardiology updated its guidelines in 2019 to reflect a maximum total dose of 3 mg, which provides more complete vagal blockade when needed, replacing the older maximum of 2.0 mg 6

The American College of Cardiology notes that doses less than 0.5 mg can cause paradoxical bradycardia due to central vagal stimulation, and recommends avoiding such doses 5
The American College of Cardiology suggests titrating atropine to a minimal effective heart rate, targeting approximately 60 bpm, rather than aggressive rate increases, particularly in acute MI 6

The American College of Cardiology recommends caution when using atropine in heart transplant recipients, as it can cause paradoxical heart block or sinus arrest in 20% of these patients due to lack of parasympathetic innervation 5
The American College of Cardiology recommends dopamine infusion at 5-20 mcg/kg/min IV, titrated to effect, as a second-line therapy for bradycardia that persists after maximum atropine dosing or is contraindicated 5
The American College of Cardiology found no difference in survival between transcutaneous pacing and dopamine in a trial of 82 patients with unstable bradycardia refractory to atropine 5