CATS 2009 Review date January 2013

CATS Clinical Guideline Supraventricular tachycardia Most tachyarrhythmias in children are due to congenital re-entrant pathways but some are secondary to poisoning, metabolic disturbance, following cardiac surgery or cardiomyopathy. 1. Assessment 1.1 Assess airway and breathing 1.2 Heart rate: perform ECG rhythm strip and12 lead ECG 1.3 SVT usually 220-300, sinus tachycardia – may be up to 220 bpm in infants

and 180 in children. 1.4 Heart rhythm – SVT is regular with no beat-to-beat variability, sinus

tachycardia has some beat-to-beat variability 1.5 P waves may or may not be present 1.6 QRS complexes – usually narrow in SVT 1.7 Is the child in cardiogenic shock?

o prolonged capillary refill o reduced blood pressure o acidotic blood gas o mental state: agitated or reduced conscious level o gallop rhythm o enlarged liver

1.8 Check electrolytes (Mg, Ca and K) and correct if necessary 1.9 Consider possible aetiologies and investigate as appropriate (see above) 2. Immediate management 2.1 Try vagal stimulation

o diving reflex o one sided carotid sinus massage o Valsalva manoeuvre in older child

2.2 Follow algorithm below 2.3 Intravenous adenosine into large peripheral vein followed by rapid saline

flush: 100 mcg/kg, 200 mcg/kg then 300 mcg/kg. A maximum dose of 500 mcg/Kg (maximum dose up to 12 mg) on the advice of paediatric cardiologist (unless age <1 month, in which case, maximum dose 300 mcg/kg)

2.4 IF ADENOSINE FAILS, DISCUSS WITH PAEDIATRIC CARDIOLOGIST. Further options may be:

o Assume cardiac dysfunction is present.

Amiodarone infusion, usually 15-25 mcg/kg/min.

CATS 2009 Review date January 2013

o If no cardiac dysfunction: Amiodarone bolus 5 mg/kg over 20 minutes, followed by repeat chemical cardioversion with adenosine if SVT persistent

o +/- elective DC cardioversion under GA

3. Indications for intubation (see CATS Intubation guideline) 3.1 Cardiac failure with acidosis 3.2 Impending cardiorespiratory collapse 4. Management following intubation 4.1 Paralyse and sedate 4.2 Correct acidosis – give up to 30 mls/kg volume, bicarbonate and consider

inotropic support (be aware that inotropes may precipitate further dysrhythmias –discuss use with CATS consultant)

4.3 Continue to try to achieve sinus rhythm (discuss with CATS consultant and paediatric cardiology SpR).

4.4 If SVT is intractable and acidosis severe consider transport to an ECMO centre for further support (discuss with CATS consultant and CICU consultant)

Treatment algorithm

Shock present?

Consider: Adenosine 500 mcg/kg

Amiodarone DC Cardioversion

Flecainide Discuss with paediatric

cardiologist

Adenosine 100 mcg/kg

Adenosine 200 mcg/kg

Vagal manoeuvres

Synchronised DC shock

2 J/kg

Synchronised DC shock

1 J/kg

Establishing vascular access quicker than

obtaining defibrillator?

No Yes

No

Yes

Consider antidysrhythmics

Discuss with paediatric cardiologist

Adenosine 300 mcg/kg

Wait 2 min

Wait 2 min