Symptomatic Bradycardia
Source: AHA Guidelines for CPR & ECC 2025 · Last reviewed: Jul 2026
1
Initial Action
Identify symptomatic bradycardia (usually HR <50/min). Secure airway, O₂ if hypoxic, monitor, 12-lead ECG, IV access.
2
Decision
Signs of hypoperfusion (hypotension, altered mental status, shock, ischaemic chest pain, acute heart failure)?
No → close observation, look for cause (drugs, ischaemia, hypothyroid, electrolyte disturbance, vagal tone). Yes → continue.
3
Atropine 1 mg IV/IO, may repeat every 3–5 min, maximum total 3 mg.
4
If unresponsive / unlikely to respond (e.g. high-grade AV block):
- Transcutaneous pacing (immediately if available), or
- Dopamine infusion 5–20 mcg/kg/min, or
- Epinephrine infusion as alternative
Quick Dose Reference
| Drug | Dose |
|---|---|
| Atropine | 1 mg IV/IO, repeat q3–5 min, max 3 mg |
| Dopamine | Infusion 5–20 mcg/kg/min |
Educational quick reference only, not a substitute for clinical judgement.