SVT Flashcards
Define SVT
Narrow complex tachycardia, dependent on the atrial tissue or AVN node. Often due to re-entry rhythm.
Causes of SVT
Congenital re-entry rhythms
Infection
Poisoning
Metabolic disturbance
Cardiomyopathy
Following cardiac surgery
Symptoms of SVT
Due to insufficient filling of the heart, there’s not enough oxygenated blood to get around, so you get:
SOB, tachycardia, tachypnoea
Chest pain, dizziness, syncope
Palpitations
In children - poor feeding, pallor, irritability
How would you clinically assess this child?
Airway, breathing
Circulation - check for cardiogenic shock
D - agitation and confusion
Exposure - rule out other causes
Electrolytes
Infection
Signs of cardiogenic shock
Prolonged CRT >2 seconds
Low blood pressure
Acidotic blood gas
Gallop rhythm
Enlarged liver
If we suspect infection, SVT could be a presenting feature of? When should we prescribe antibiotics?
Myocarditis
Give Ab if neonates
What electrolytes would you check for?
Magnesium
Phosphate
Calcium
Potassium
You should check drug levels if the patient is on which two drugs?
Digoxin
Theophylline
If there is no cardiogenic shock, how would you manage?
VAGAL manoeuvre
If no shock, vagal manoeuvre hasn’t worked, what do you do?
100mcg/kg of Adenosine
Wait 2 mins
If no response
200mcg/kg of adenosine, wait 2 mins
If no response
300mcg/kg of adenosine, wait two minutes
If 300mcg/kg hasn’t worked in a non-shocked patient?
Adenosine 400 -500mcg/kg* but maximum 12mg if neonate
Synchronous DC shock
Or Amiodarone
Or other antiarrhythmics
Discuss with Paediatric Cardiologist
What is the max dose of adenosine at each round?
3mg, 6mg then 12mg
If the patient is in cardiogenic shock, what do you do?
Large bore cannulae / IV access then try adenosine
If the patient is in cardiogenic shock, and you can’t find IV access, what do you do?
DC synchronised shock 1J/kg, if it hasn’t worked then 2J/kg and repeat the 2J/kg
If DC cardioversion hasn’t worked, what do you do?
Consider anti-dysrhythmics, and discuss with paediatric cardiology
