Brugada Criteria

The following should be noted:

Is there an absence of RS complexes in all the chest leads?

Is the R-S interval (interval between the tip of the R wave and the lowest part of the S wave) > 100mS in any V lead?

Are there capture beats, fusion beats, or evidence of AV dissociation?

Does the morphology of the QRS complex in leads V1/ V6 suggest VT?

Morphologic Criteria suggestive of VT

1. RBBB morphology

V1:     Monophasic R wave
QR wave
RS wave

V6:     Monophasic R wave
QR wave
R wave smaller than the S wave

2. LBBB morphology

V1:      R wave > 30 msec wide
RS wave > 60 msec wide

V6:     QR wave
QS wave

If the answer to any of these questions is YES then the diagnosis is VT.

If the answer to all of these questions is NO then the diagnosis is SVT with a bundle branch block.

Brugada et al. showed that application of these criteria to a sample of 554 patients had a sensitivity of 98.7% and a specificity of 96.5% in making the correct diagnosis [8].

The main pitfall with these criteria is that they are not easy to apply or remember.

Learning bite

Objective criteria for distinguishing between VT and SVT with aberrant conduction are irrelevant if the patient is unstable. Synchronised DC cardioversion is required.