Quick Chart
  • A dysrhythmia refers to an abnormality of the heart rhythm.
  • Although not all patients will become unstable and show adverse signs, brady-dysrhythmias (<60bpm) and tachy-dysrhythmias (>100bpm) have the potential to severely compromise cardiac output and lead to cardiac arrest.
  • Supraventricular tachycardia (SVT) is a common cardiac dysrhythmic disturbance. It is narrow complex and regular, usually of rapid onset and is typically defined as having an absence of P waves.
  • Rates can range from +/- 150bpm, can be slower, although are often much faster. Typically, SVT is not usually life threatening and can be self-resolving.
  • Patients presenting with cardiac dysrhythmia, demonstrating adverse signs such as distress and fatigue may require urgent transport.
 Clinical Presentation

Unstable bradycardia (with pulse and not associated with traumatic cause):

  • Poor signs of perfusion, including:
    • Hypotension
    • Altered conscious state
    • Diaphoresis
    • Shortness of breath and/or cyanosis
    • Syncope

Unstable tachycardia (with pulse)

  • Unstable indicates that cardiac output has reduced to produce blood pressure changes, altered mental status, ischaemic chest pain, hypotension, syncope or other signs of shock.

Supraventricular tachycardia (SVT):

  • Pulse > approx 150 bpm, rapid onset, regular, with diaphoresis and signs or symptoms of reduced cardiac output.
 Exclusion Criteria
Exclusion Criteria
 Risk Assessment
  • Nil
Primary Care
Intermediate Care
  • Apply cardiac monitor including a 12 Lead if available, trained and authorised
  • Pain relief: If pain >3/10 post 1x spray of GTN, administer Methoxyflurane
  • Consider ondansetron if required
  • Monitor patient persistently, recording full observations every 10 minutes (or 5 minutes if time critical)
  • Transport Priority 1 if patient time critical, pre-notifying receiving facility
Advanced Care
Unstable bradycardia:
  • Address reversible cause:
    • If inferior/right ventricular MI associated with bradycardia and hypotension, consider IV saline to address cardiogenic shock and follow STEMI protocol.
    • Hypovolaemia, hypoxia and some toxins that can be addressed in the field.
  • Consider Atropine Sulphate, if likely to have effect. Atropine would not be effective in 3rd degree Heart Blocks or in wide complex bradycardias.
  • Consider ASMA consult for advice.
Critical Care (CCP) only
Consider transcutaneous pacing
Unstable tachycardia:
  • Early recognition.
  • 12 Lead ECG should not delay transport.
  • Consider proximity to ED; consider ASMA consult if delivery to ED will be delayed.
  • Consider patient in peri-arrest state.
Supraventricular tachycardia (narrow complex, rapid rate, regular):
  • Consider pain relief
  • Consider anti-emetic
  • Monitor patient continuously, recording full observations every 10 minutes (or 5 minutes if time critical)
  • Transport Priority 1 if patient time critical, pre-notifying receiving facility
Critical & Extended Care
Narrow complex tachycardia (irregular):
  • If atrial fibrillation, consider Amiodarone (if onset <48 hours)
  • Transport for rate control
Broad complex tachycardia (regular):
  • Early recognition
  • 12 Lead ECG should not delay transport
  • Synchronised cardioversion
  • Consider Amiodarone if cardioversion unsuccessful
Broad complex tachycardia (irregular):
  • Resuscitation equipment should be at hand
  • Consider unstable patient as being time-critical and in a peri-arrest state.
 Additional Information
  • Resuscitation equipment should be at hand.
  • Consider unstable patient as being time-critical, possible peri-arrest.
Key Terms & Links
Extended Care:
Colour assist:


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