Approach to the Wide Complex Tachycardia

During wide complex tachycardia (heart rate > 100/min, QRS > 0.12 sec) the differentiation between supraventricular and ventricular origin of the arrhythmia is important to guide therapy. Several algorhythms have been developed to aid in this differentiation.

The ACC algorhythm [1]

SVT vs VT algorhytm. Adapted from [1]

Brugada criteria

Brugada criteria to differentiate SVT from VT [2]
Are there fusion or capture beats? (this is not an item from Brugada, it is however very specific	Yes? => VT	specificy=100%
RS complexen missing in the chest leads?	Yes? => VT	sensitivity=21% specificity=100%
RS-interval in one of the cheast leads > 100 msec (in the absence of anti-arrhythmics)?	Yes? => VT	sensitivity=66% specificity=98%
AV-dissociation?	Yes? => probably VT (Note AVNRT can also present with AV dissociation!)	sensitivity=82% specifity=98%
Morphological criteria (if the above criteria are inconclusive)
LBBB pattern
Initial R more than 40ms?	Yes => VT
Slurred or notched downwards leg of S wave in leads V1 or V2	Yes => VT
Beginning of Q to nadir QS >60 ms in V1 or V2?	Yes => VT	LR >50:1
Q or QS in V6?	Yes => VT	LR >50:1
RBBB pattern
Monofasic R or qR in V1?	Yes => VT
R taller than R' (rabbit-ear sign)?	Yes => VT	LR >50:1
rS in V6?	Yes => VT	LR >50:1

Examples

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  Wide complex tachycardia. No AV dissociation. RBBB. Resembles sinus rhythm from the same patient. Conclusio SVT with RBBB

• 

  ECG from the same patient in sinus rhythm. The QRS complex is very similiar.

• 

  Wide complex tachycardia. LBBB configuration. Absence of RS in the chest leads. AV dissociation is present. Conclusion: VT

• 

  Wide complex tachycardia. LBBB configuration. Absence of RS in the chest leads. AV dissociation is present. Conclusion: VT

Referenties

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