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* Younger patient with known paroxysmal tachycardias and who is hemodynamically stable = most like SVT | * Younger patient with known paroxysmal tachycardias and who is hemodynamically stable = most like SVT | ||
== The ACC algorithm <cite>ACC</cite>== | == The ACC algorithm <cite>ACC</cite>== | ||
[[File: | [[File:VT_algorithm_en.svg|800px|thumb|left|SVT vs VT algorhytm. Adapted from <cite>ACC</cite>]] | ||
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==ECG algorithms to differentiate wide QRS-complex tachycardias== | ==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: | 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: | ||
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== Ultrasimple Brugada criterion: RW to peak Time (RWPT) == | == 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. | [[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. | ||
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== Vereckei aVR algorithm <cite>Vereckei</cite>== | == Vereckei aVR algorithm <cite>Vereckei</cite>== |