What is the first line treatment for bradycardia, including atropine (anticholinergic) dose and frequency?

From the Guidelines

Atropine is the first-line medication for symptomatic bradycardia, with a recommended dose of 0.5–1 mg IV, which can be repeated every 3–5 minutes as needed, up to a maximum dose of 3 mg. This is based on the most recent and highest quality study, which is the 2019 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1. The guideline recommends atropine as the initial treatment for symptomatic sinus bradycardia or atrioventricular block, with a dosage of 0.5–1 mg IV, repeated every 3–5 minutes as needed, up to a maximum dose of 3 mg.

Key Points

• Atropine works by blocking parasympathetic (vagal) influences on the heart, increasing the firing rate of the sinoatrial node and enhancing conduction through the atrioventricular node.
• Atropine should be used for symptomatic bradycardia, which is defined as bradycardia with signs of hemodynamic instability, such as hypotension, altered mental status, chest pain, or heart failure.
• If atropine is ineffective, alternative interventions include transcutaneous pacing, dopamine infusion (5 to 20 mcg/kg/min), or epinephrine infusion (2–10 mcg/min) 1.
• Doses less than 0.5 mg of atropine should be avoided, as they may paradoxically worsen bradycardia due to central vagal stimulation.

Additional Considerations

• The 2010 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations also supports the use of atropine as the first-line treatment for symptomatic bradycardia, with a recommended dose of 0.5 to 1 mg IV, repeated as needed to a total of 1.5 to 3 mg 1.
• The 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care also recommend atropine as the first-line drug for acute symptomatic bradycardia, with a recommended dose of 0.5 mg IV every 3 to 5 minutes to a maximum total dose of 3 mg 1.

From the FDA Drug Label

Adult dosage ... Bradyasystolic cardiac arrest: 1 mg dose, repeated every 3 to 5 minutes if asystole persists. ( 2)

The first line treatment for bradycardia is atropine. The recommended dose and frequency for atropine in the context of bradyasystolic cardiac arrest is an initial dose of 1 mg, repeated every 3 to 5 minutes if asystole persists 2.

• Key points:
  • Atropine dose: 1 mg
  • Frequency: every 3 to 5 minutes if asystole persists
  • Indication: Bradyasystolic cardiac arrest

From the Research

First Line Treatment for Bradycardia

• The first line treatment for symptomatic bradycardia is atropine 3

Atropine Dose and Frequency

• The study does not specify the exact dose and frequency of atropine for bradycardia treatment
• However, another study suggests that patients with hemodynamically unstable bradycardia may respond to a single dose of atropine, and those with bradycardia are more likely to receive a lower total dose of atropine compared to those with atrioventricular block (AVB) 4

Treatment of Bradycardia

• Treatment of bradycardia may also involve correcting the underlying cause, pharmacologic interventions, and temporary pacing 5
• In some cases, a permanent pacemaker may be required, especially for patients with sick sinus syndrome or high-degree atrioventricular blocks 3, 6