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| {{Ventricular tachycardia}}
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| {{CMG}}
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| '''Associate Editor-In-Chief:''' {{CZ}}
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| ==Overview==
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| Ventricular tachycardia can be classified under three main categories; the morphology of complexes on EKG, the duration of the episode, and the symptoms.
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| ==Classification Based Upon Morphology of Complexes==
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| Ventricular tachycardia can be classified based on its ''morphology'': [[Monomorphic ventricular tachycardia]] means that the appearance of all the beats match each other in each lead of a surface [[electrocardiogram]] (EKG).
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| [[Polymorphic ventricular tachycardia]], on the other hand, has beat-to-beat variations in morphology. This most commonly appears as a cyclical progressive change in cardiac axis referred to by its French eponym [[Torsade de pointes]] (literally twisting of the points).
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| [[Image:Electrocardiogram of Ventricular Tachycardia.png|thumb|center|500px|12 lead [[electrocardiogram]] showing a run of monomorphic ventricular tachycardia (VT)]]
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| ==Classification Based Upon Duration of Episode==
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| Another way to classify [[ventricular tachycardia]]s is the ''duration of the episodes'': Technically, three or more beats in a row on an EKG that originate from the ventricle at a rate of more than 100 beats per minute constitute a [[ventricular tachycardia]]. If the fast rhythm self-terminates within 30 seconds, it is considered a '''non-sustained ventricular tachycardia'''. If the rhythm lasts more than 30 seconds it is known as a '''sustained ventricular tachycardia''' (even if it terminates on its own after 30 seconds).
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| ===Sustained Ventricular Tachycardia===
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| * Ventricular tachycardia originates from a ventricular focus
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| * Lasts more than 30 seconds
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| * Broad [[EKG|QRS]] complexes: rate of >90 beats/minute
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| === Paroxysmal Ventricular Tachycardia(Non Sustained Ventricular Tachycardia) ===
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| * Rapid succession of three or more ectopic beats.
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| * Sustained if it lasts longer than 30 seconds.
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| ===Incessant Ventricular Tachycardia===
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| * The ventricular tachycardia is recurrent and the episodes are interrupted by only a few sinus beats.
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| ==Classification Based Upon Symptoms==
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| A third way to classify [[ventricular tachycardia]] is on the basis of its symptoms: [[Pulseless VT]] is associated with no effective [[cardiac output]], hence, no effective pulse, and is a cause of [[cardiac arrest]]. In this circumstance it is best treated the same way as [[ventricular fibrillation]] ([[VF]]) and is recognized as one of the shockable rhythms on the [[cardiac arrest]] protocol. Some [[VT]] is associated with reasonable cardiac output and may even be asymptomatic. The heart usually tolerates this rhythm poorly in the medium to long term, and patients may certainly deteriorate to [[pulseless VT]] or to [[VF]].
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| ==References==
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| {{reflist|2}}
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| {{WH}}
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| {{WS}}
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