Differentiating VT from SVT with abN conduction

Brugada criteria

You can try applying the Brugada criteria to the ECG. The criteria are not 100% reliable.

  • Is there an absence of RS complexes in all the chest leads?
  • Is the R-S nadir (interval betw. the start of the QRS complex and the lowest part of the S wave) > 100mS in any V lead?
  • Are there capture beats, fusion beats, or evidence of AV dissociation?
  • Is there an absence of typical classical BBB?

Yes to any = VT, No to all= SVT

If there is any doubt, or you are not sure how to apply these criteria, assume the rhythm is VT

Differentiating Polymorphic VT from AF with pre-excitation

  • Broad complex tachycardia
  • Irregularly irregular
  • Very short R-R intervals
  • "Pure" delta waves
  • More on WPW

If there is any doubt treat as for VT but do not use agents that block the AV node (such as Adenosine )

ECG in WPW with AF

Content by Dr Íomhar O' Sullivan. Last review Dr ÍOS, Dr Brian O' Riordan 11/04/23.