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Ventricular Tachycardia: Difference between revisions
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Ventricular tachycardia is defined as a sequence of three or more ventricular beats. The frequency must by higher than 100 bpm, mostly it is 110-250 bpm. | Ventricular tachycardia is defined as a sequence of three or more ventricular beats. The frequency must by higher than 100 bpm, mostly it is 110-250 bpm. | ||
Ventricular tachycardias often origin around old scar tissue in the heart, e.g. after myocardial infarction. Also electrolyte disturbances and ischemia can cause ventricular tachycardias. The cardiac output is often strongly reduced during VT resulting in hypotension and loss of conciousness. VT is a medical emergency as it can deteriorate into [[#Ventricular fibrillation|Ventricular fibrillation]] and thus mechanical cardiac arrest. | Ventricular tachycardias often origin around old scar tissue in the heart, e.g. after myocardial infarction. Also electrolyte disturbances and ischemia can cause ventricular tachycardias. The cardiac output is often strongly reduced during VT resulting in hypotension and loss of conciousness. VT is a medical emergency as it can deteriorate into [[#Ventricular fibrillation|Ventricular fibrillation]] and thus mechanical cardiac arrest. Although ventricular tachycardia is often associated with cardiac disease, short non-sustained VTs during exercise in otherwise healthy individuals, are not necesarrily associated with a worse prognosis <cite>NSVT</cite>. | ||
Ventricular tachycardia can be catechorized as follows: | Ventricular tachycardia can be catechorized as follows: | ||
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*'''Polymorphic VT''': the ventricular beats have a changing configuration. The RR interval is 180-600 ms (comparable to a heart rate of 100-333 bpm). | *'''Polymorphic VT''': the ventricular beats have a changing configuration. The RR interval is 180-600 ms (comparable to a heart rate of 100-333 bpm). | ||
*'''Biphasic VT''': a ventricular tachycardia with a QRS complex that alternates from beat to beat. Associated with [[Miscellaneous#Digoxin|digoxin intoxication]] and [[lqts|long QT syndrome]]. | *'''Biphasic VT''': a ventricular tachycardia with a QRS complex that alternates from beat to beat. Associated with [[Miscellaneous#Digoxin|digoxin intoxication]] and [[lqts|long QT syndrome]]. | ||
Ventricular tachycardia can be difficult to diagnose when confronted with a wide complex tachycardia. A seperate chapter deals with [[Approach_to_the_Wide_Complex_Tachycardia|ECG algorithms to analyze wide complex tachycardias]]. | |||
==Localisation of the origin of a ventricular tachycardia== | ==Localisation of the origin of a ventricular tachycardia== | ||
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<biblio> | <biblio> | ||
#segal pmid=17338765 | #segal pmid=17338765 | ||
#NSVT pmid=23747767 | |||
</biblio> | </biblio> | ||