====== Bradycardia Algorithm ======

Bradycardia is defined as:

  * Heart rate < 60 bpm

Clinical relevance depends on:
  * Symptoms
  * Hemodynamic stability
  * Presence of AV block

This page follows the [[cardio:arrhythmias:start|Dysrhythmias Module]] and mirrors ACLS principles.

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===== Step 1 – Identify Symptomatic vs Asymptomatic =====

Assess:

  * Hypotension
  * Altered mental status
  * Signs of shock
  * Ischemic chest discomfort
  * Acute heart failure

If **NO symptoms**:
  → Monitor  
  → Evaluate underlying cause  
  → No emergent therapy required  

If **SYMPTOMATIC**:
  → Proceed to Step 2

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===== Step 2 – Determine Rhythm =====

Common causes:

  * [[cardio:arrhythmias:sinus_bradycardia|Sinus Bradycardia]]
  * [[cardio:arrhythmias:av_block|AV Block]]
  * Medication-induced bradycardia
      * [[cardio:beta_blockers:start|Beta-Blockers]]
      * [[cardio:ccb:non_dhp|Non-DHP Calcium Channel Blockers]]
      * [[cardio:arrhythmias:digoxin|Digoxin]]
      * [[cardio:arrhythmias:amiodarone|Amiodarone]]

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===== Step 3 – Immediate Treatment (Unstable Bradycardia) =====

==== First-Line Medication ====

[[cardio:arrhythmias:atropine|Atropine]]

  * 1 mg IV push
  * Repeat every 3–5 minutes
  * Maximum total dose: 3 mg

Mechanism:
  * Blocks vagal tone at SA/AV node

Not effective in:
  * Infranodal block
  * High-grade distal AV block

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===== Step 4 – If Atropine Ineffective =====

Escalate immediately:

==== Transcutaneous Pacing ====

  * Initiate external pacing
  * Provide sedation if patient conscious

See:
  * [[cardio:arrhythmias:av_block|Advanced AV Block]]

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==== OR Start Infusion ====

[[cardio:vasopressors:dopamine|Dopamine]] infusion  
OR  
[[cardio:vasopressors:epinephrine|Epinephrine]] infusion  

Used when pacing not immediately available.

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===== Special Scenarios =====

==== High-Grade AV Block (Mobitz II or Complete Heart Block) ====

  * Often does NOT respond to [[cardio:arrhythmias:atropine|Atropine]]
  * Early pacing is preferred
  * Cardiology consultation required

See:
  * [[cardio:arrhythmias:av_block|AV Block]]

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==== Beta-Blocker Toxicity ====

  * Consider [[toxicology:glucagon|Glucagon]]
  * High-dose insulin euglycemia therapy
  * Vasopressors

See:
  * [[cardio:beta_blockers:start|Beta-Blockers]]

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==== Calcium Channel Blocker Toxicity ====

  * IV calcium
  * Insulin therapy
  * Vasopressors

See:
  * [[cardio:ccb:non_dhp|Non-DHP CCBs]]

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==== Digoxin Toxicity ====

  * [[cardio:arrhythmias:digoxin|Digoxin]]
  * Consider [[cardio:arrhythmias:digoxin_immune_fab|Digoxin Immune Fab]]

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===== Full Flow (Quick View) =====

Bradycardia →  
Is patient symptomatic?

NO → Monitor  

YES →  
Give [[cardio:arrhythmias:atropine|Atropine]]

If no response →  
Transcutaneous pacing  

If pacing unavailable →  
[[cardio:vasopressors:dopamine|Dopamine]] or [[cardio:vasopressors:epinephrine|Epinephrine]] infusion  

Consider reversible causes.

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===== Reversible Causes =====

  * Hypoxia
  * Electrolyte abnormalities
  * Drug effects
  * Increased vagal tone
  * Ischemia

Always treat underlying cause.

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===== Clinical Pearls =====

  * Treat the patient, not just the number.
  * Asymptomatic bradycardia does not require emergent therapy.
  * Atropine works at the AV node — not distal conduction tissue.
  * Early pacing saves time in high-grade block.
  * Always review medication list.

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===== Related =====

  * [[cardio:arrhythmias:start|Dysrhythmias Module]]
  * [[cardio:arrhythmias:atropine|Atropine]]
  * [[cardio:arrhythmias:adenosine|Adenosine]]
  * [[cardio:arrhythmias:av_block|AV Block]]
  * [[cardio:beta_blockers:start|Beta-Blockers]]
  * [[cardio:ccb:start|Calcium Channel Blockers]]
  * [[cardio:intro:start|Cardiovascular Pharmacology]]