Approach to the Wide Complex Tachycardia: Difference between revisions

* Younger patient with known paroxysmal tachycardias and who is hemodynamically stable = most like SVT

== The ACC algorithm <cite>ACC</cite>==

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==ECG algorithms to differentiate wide QRS-complex tachycardias==

Several ECG algorithms have been developed to differentiate wide QRS-complex tachycardias. Most of them performed very well in the population they were based upon. A recent review tested five commonly used algorithms in a control population and found that each of them only performed reasonably well in differentiating VT from SVT (accuracy 66-77%).<cite>Jastrzekbsi</cite> The five criteria tested were:

== Ultrasimple Brugada criterion: RW to peak Time (RWPT)  ==

[[File:RWPT.svg|thumb|right|300px|R-wave to Peak Time ≥ 50ms in lead II strongly suggests VT]]In 2010 Joseph Brugada et al. published a new criterion to differentiate VT from SVT in wide complex tachycardias: the R wave peak time in Lead II <cite>Brugada2</cite>. They suggest measuring the duration of onset of the QRS to the first change in polarity (either nadir Q or peak R) in lead II. If the RWPT is ≥ 50ms the likelihood of a VT very high (positive likelihood ratio 34.8). This criterion was successful in their own population of 163 selected patients and is awaiting prospective testing in a larger trial.

== Vereckei aVR algorithm <cite>Vereckei</cite>==

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The Griffith algorithm <cite>Griffith</cite>reverses the diagnostic strategy:  unless simple rules for a positive diagnosis of supraventricular tachycardia are satisfied, ventricular tachycardia is diagnosed by default. The algorithm only looks at bundle brach block morphology. Supraventricular tachycardia is diagnoses when ECG findings match typical bundle branch block:

* LBBB: rS or QS wave in leads V1 and V2, delay to S wave nadir < 70 ms, and R wave and no Q wave in lead V6