Advanced Cardiac Life Support (ACLS): Bradycardia

Updated: Aug 28, 2023
Author: James J Lamberg, DO; Chief Editor: Meda Raghavendra (Raghu), MD 

Advanced Cardiac Life Support (ACLS): Bradycardia

ACLS: Bradycardia

1. Initial evaluation is as follows:[1, 2, 3, 4, 5]

  • Assess appropriateness for clinical condition (pulse present and unstable).
  • Heart rate typically less than 50 bpm in bradyarrhythmia

2. Initial intervention is as follows:

  • Maintain patent airway and assist breathing, as needed.
  • Administer oxygen if hypoxemic.
  • Attach monitor/defibrillator.
  • Monitor blood pressure and oximetry.
  • Obtain intravenous (IV)/intraosseous (IO) access.
  • Perform 12-lead electrocardiography (ECG); do not delay therapy.

3. Assess for signs of poor perfusion, as follows:

  • Hypotension (systolic blood pressure [SBP] < 90 mm Hg)
  • Acutely altered mental status
  • Signs of shock
  • Ischemic chest discomfort
  • Acute heart failure

4. Therapeutic intervention is as follows:

  • If poor perfusion present, administer atropine.
  • If adequate perfusion present, monitor and observe.

5. Measures if atropine is ineffective are as follows:

  • Transcutaneous pacing OR dopamine infusion OR epinephrine infusion
  • Consider expert consultation and transvenous pacing.

Drug Therapy

Drug therapy is as follows:

  • Atropine 1 mg IV q3-5min; maximum dose, 3 mg  NOTE: This is changed from the 2015 guidelines.
  • Dopamine 2-20 μg/kg/min infusion; titrate to patient response; taper slowly.
  • Epinephrine 2-10 μg/min infusion; titrate to patient response.


Considerations for atropine administration are as follows:

  • Not reliable for third-degree block or second-degree type II block
  • Could potentially exacerbate the block by increasing sinoatrial (SA) node activation
  • May be ineffective in patients after heart transplantation

Most Recent Guideline Changes

Changes from the 2015 guidelines include the following:

  • The 2020 adult bradycardia algorithm increased the atropine dose to 1 mg (from 0.5-1 mg) but the frequency of dosing remains the same at every 3-5 minutes with a maximum of 3 mg.