Paediatric Clinical Guidelines

Cardiology

2.1 Supraventricular Tachycardia

Short Title: / Supraventricular Tachycardia
Full Title: / Guideline for the investigation and management of supraventricular tachycardia in children and young people
Date of production/Last revision: / August 2008
Explicit definition of patient group to which it applies: / This guideline applies to all children and young people under the age of 19 years.
Name of contact author / Dr Muthu Dhanarass, Paediatric SpR
Dr Damian Wood, Consultant Paediatrician
Ext: 67319
Revision Date / August 2011
This guideline has been registered with the Trust. However, clinical guidelines are 'guidelines' only. The interpretation and application of clinical guidelines will remain the responsibility of the individual clinician. If in doubt contact a senior colleague or expert. Caution is advised when using guidelines after the review date.

Supraventricular Tachycardia

Please note there is a separate neonatal supraventricular tachycardia guideline for infants less than 28 days of age.

Introduction

  • SVT is the commonest symptomatic arrhythmia in children
  • Typically
  • The heart rate is usually above 200.
  • 12 lead ECG shows a narrow complex, regular tachycardia.
  • If present, p waves are seen for each QRS complex.

Assessment

History:Infants – pallor, tachypnoea, poor feeding, irritability

Older children – palpitations, chest discomfort, dizziness

Often non-specific such as “feeling funny”

Examination:Heart rate over 180 bpm (over 220/min in infants)

No beat to beat variation as in sinus tachycardia

Hypotension may be present

Heart failure (esp. in infants)

Investigations:12 lead ECG if suspected

Urgent cardiology referral if tachycardia is broad complex

Or irregular

Other – if on medication, measure levels i.e. Digoxin,

Theophylline.

Management

  • Move to Resuscitation area when safe to do do
  • Assess ABC
  • Check BP and start continuous cardiac monitoring with paper recording
  • Oxygen Saturation.
  • 12 lead ECG-Rhythm strip (P waves may not be visible)

Algorithm for the Management of Supraventricular Tachycardia

If Shocked

1. Call for senior help,

2. Make sure airway equipment available

IF HAEMODYNAMICALLY STABLE – consider before drug treatment

  1. Vagal manoeuvre
  2. Bag of ice on face, Max. Duration 15 secs. (Ice cubes available in Children’s Emergency Department Refrigerator )
  3. Facial Immersion – wrap infant in towel, and immerse the whole head in iced water for 5 seconds. No need to obstruct the mouth or nose.
  4. Unilateral carotid massage
  5. Valsalva in older children

DO NOT USE EYEBALL PRESSURE IN CASES OF SVT

IV Access – in large PROXIMAL vein preferably with a 3 way tap

Adenosine

  • Prepare all doses of adenosine (as in algorithm) and 5ml saline flushes
  • Start with adenosine 100mcg/kg
  • Turn on ECG paper recorder
  • RAPIDLY administer adenosine as push, followed IMMEDIATELY by saline flush
  • If rhythm does not revert to Sinus rhythm, repeat Adenosine at increasing doses. Maximum dose is 300mcg/kg (<1 month); 500mcg/kg (>1 month) up to maximum of 12 mg.
  • For adolescents adenosine doses can be rounded as 3mg followed by 6mg and then 12mg

Perform ECG post reversion

Adenosine side effects – flushing, nausea, chest tightness.

Caution should be taken if patients are on Dipyrimadole – it prolongs the action of the adenosine. The dosage of adenosine should be reduced by a factor of 4.

IF THESE MEASURES FAIL, Contact the ON-CALL ACUTE PAEDIATRIC CONSULTANT and discuss with Dr Thakker or Paediatric Cardiologist at Glenfield Hospital(0116 2871471) and fax the ECG to cardiac centre

Other Drugs Used in the Treatment of SVT

One of the following drugs may be suggested. But many of them are unsafe to use in the same patient. The patient can be treated by external cardioversion with a general anaesthesia, but we strongly recommend discussion with the on call Paediatric Cardiologist before administration of drugs other than Adenosine.

Give on PICU only, monitoring BP and ECG closely. Make sure defibrillator and pacemaker facilities available.

Amiodarone:

Used in refractory atrial tachycardia, (Dose 5mg/kg over 30mins, Dilute in 4ml/kg of 5% Dextrose)

Procainamide: Loading dose 15mg/kg over 30 to 60 mins with ECG and BP monitoring. STOP if QRS complex widens in ECG or Blood pressure falls.

Flecainide

2mg/kg IV over 20 minutes

Particularly useful for WPW

STOP if new arrhythmias in ECG and changes in QRS.

Verapamil

Should not be given if

  • <1 year of age (risk of irreversible hypotension, asystole)
  • Beta-blocker (eg.propronolol) used within the last 24 hrs
  • if there are signs of heart failure or poor LV function

Administer as slow IV

  • Age 1-2 years, 100 to 200 mcg/kg (max 2g) over 3 mins
  • Over 2 years 100 to 300 mcg/kg (max 5g)

STOP infusion if sinus rhythm achieved or BP drops greater than 10mmHg

Muthu DhanarassPage 1 of 3October 2004