Supraventricular tachycardia

Disclaimer

These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline. 

Read the full PCH Emergency Department disclaimer.

Aim

To guide staff with the assessment and management of supraventricular tachycardia.

Background

  • Rapid regular, usually narrow (< 0.08 sec) complex tachycardia of 220 to 320 bpm in infants and 150 to 250 bpm in older children
  • Supraventricular tachycardia (SVT) may be well tolerated in infants for 12 to 24 hours, heart failure later manifests with irritability, poor perfusion, pallor, poor feeding and then rapid deterioration
  • Do not use verapamil or beta blockers in infants or children with SVT - cause profound AV block, negative inotrophy and sudden death
  • Several atrial rhythms; atrial flutter, atrial fibrillation and sinoatrial node re‐entry tachycardia are considered subgroups of re‐entrant SVT. 
    • These do not respond to adenosine but the transient slowing of the ventricular rate may unmask the atrial activity and therefore underlying cause of the SVT. A running rhythm strip is therefore imperative.

Management 

  • Assess and manage ABC
  • A 12 lead ECG in SVT and post conversion is essential 
  • Monitoring with a rhythm strip during manoeuvres (i.e. in SVT and post conversion) allows later assessment of underlying rhythm in unclear cases.

Child Appears Shocked 

  • Hypotensive
  • Poor peripheral perfusion
  • Reduced GCS 
  • Seek urgent senior assistance 
  • Insert IV/IO
  • Administer sedation if child is conscious
    • Sedation requires a senior doctor (e.g. ED, PICU, Anaesthetist) 
  • Synchronous DC shock
    • 1st shock – 1 Joule/kg
    • 2nd shock – 2 Joules/kg
    • 3rd shock – 2 Joules/kg
  • Consider amiodarone in discussion with Cardiologist

Child Does Not Appear Shocked 

  • Attempt Vagal Manoeuvres
    • Infants: ice plus water in bag placed on the face for up to 10 seconds – often effective
    • Older children: carotid sinus massage, valsalva manoeuvre (30 to 60 seconds), deep inspiration/cough/gag reflex, blow through straw

If unsuccessful

  • Insert peripheral intravenous cannula as proximal as possible with 3 way tap
  • Turn on continuous trace monitoring
  • Administer rapid IV adenosine bolus. Follow bolus immediately with a 0.9% saline flush (minimum of 5mL)
    • 1st dose: 0.1mg/kg and wait 2 minutes
    • Maximum single dose 12mg 
  • Further doses 2 minutes apart if required up to the maximum dose
    • 2nd dose: 0.2mg/kg and wait 2 minutes
    • 3rd dose: 0.3mg/kg

  • If reversion to sinus rhythm occurs but is not sustained, there is little to be gained by persisting with that manoeuvre/drug
  • Discuss with Cardiologist.

Nursing

Observations

  • Baseline observations include temperature, pulse rate, respiratory rate, blood pressure, SpO2
  • 12 lead ECG as soon as possible and have it reviewed by a doctor
  • Continuous cardiac monitoring using the defibrillator is preferable as printing and recording an event is instant
  • If unwell or unstable – Minimum of 15 minutely pulse rate, respiratory rate, blood pressure and SpO2 
  • If stable and in sinus rhythm – hourly observations
  • Continuous cardiac monitoring for 1 hour post resolution of SVT or longer if specified by medical staff.

Other nursing considerations 

  • Reassure the child
  • Vagal manoeuvres such as ice water on face, valsalva manoeuvre and carotid body massage will often be attempted after medical review
    • If this is unsuccessful then it is likely that the child will require intravenous adenosine. 

Bibliography

  1. Advanced Paediatric Life Support: The Practical Approach. 6th edition. Australian and New Zealand Version. Wiley-Blackwell, 2017.
  2. Textbook of Paediatric Emergency Medicine 2nd Edition Cameron Elesevier 2012
  3. Fleisher, Gary R. Ludwig, Stephen. Textbook of Pediatric Emergency Medicine, 6th Edition. 2010

Endorsed by:  Director, Emergency Department  Date:  Jan 2018


 Review date:   Jan 2021


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