SVT

Question 1

definition

Answer 1

• Whilst strictly speaking the term supraventricular tachycardia (SVT) refers to any tachycardia that is not ventricular in origin the term is generally used in the context of paroxysmal SVT.
• Episodes are characterised by the sudden onset of a narrow complex tachycardia, typically an atrioventricular nodal re-entry tachycardia (AVNRT).
• Other causes include atrioventricular re-entry tachycardias (AVRT) and junctional tachycardias.

Question 2

Acute management

Answer 2

• vagal manoeuvres: e.g. Valsalva manoeuvre
• intravenous adenosine 6mg → 12mg → 12mg: contraindicated in asthmatics - verapamil is a preferable option
• electrical cardioversion

Question 3

Prevention of episodes

Answer 3

beta-blockers
radio-frequency ablation