Ventricular Tachycardia: Difference between revisions

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| example = An example of a polymorphic ventricular tachycardia [[Image:vtach.png|250px|Ventricular Tachycardia (VT or V-tach)]]
| example = An example of a polymorphic ventricular tachycardia [[Image:vtach.png|250px|Ventricular Tachycardia (VT or V-tach)]]
| example2 = Ventricular tachycardia on a 12 lead recording[[Image:12lead_vt1.jpg|thumb|Ventricular tachycardia of 140 bpm with a left bundle branch block and a left axis.]]
| example2 = Ventricular tachycardia on a 12 lead recording[[Image:12lead_vt1.jpg|thumb|Ventricular tachycardia of 140 bpm with a left bundle branch block and a left axis.]]
| animation = <flash>file=TenTusscherVT.swf|width=300|height=300|quality=best|align=right||</flash>  
| animation = <flashow>http://nl.ecgpedia.org/images/7/73/TenTusscherVT.swf|width=300|height=300|quality=best|align=right||</flashow>  
| animationdesc = This movie shows a computer model of ventricular tachycardia in the human heart. The VT in this example is initiated by a ventricular extrasystole and maintained by a re-entry rotor inferior in the left ventricle.<cite>tentusscher</cite> In reality, this is possibly not the etiology of VT in diseased hearts, however it is very illustrative. Read [[Copyright|this]] if you want to use this image in a presentation. [[Media:TenTusscherVT.swf|Link to the file / enlargement]]
| animationdesc = This movie shows a computer model of ventricular tachycardia in the human heart. The VT in this example is initiated by a ventricular extrasystole and maintained by a re-entry rotor inferior in the left ventricle.<cite>tentusscher</cite> In reality, this is possibly not the etiology of VT in diseased hearts, however it is very illustrative. Read [[Copyright|this]] if you want to use this image in a presentation. [[Media:TenTusscherVT.swf|Link to the file / enlargement]]
}}
}}
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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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*'''Monomorphic VT''': all ventricular beats have the same configuration.
*'''Monomorphic VT''': all ventricular beats have the same configuration.
*'''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]].
*'''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==
 
The localisation of the origin (or exit site) of a ventricular tachycardia can be helpful in understanding the cause of the VT and is very helpful when planning an ablation procedure to treat a ventricular tachycardia. [[Localisation of the origin of a ventricular tachycardia]] is discussed in a seperate chapter.
 
==Examples==
==Examples==
<gallery >
<gallery >
Image:12lead_vt1.jpg|Ventricular tachycardia of 140 bpm with a [[LBBB|left bundle branch block]] pattern and left [[heart axis]].
Image:12lead_vt1.jpg|Ventricular tachycardia of 140 bpm with a [[LBBB|left bundle branch block]] pattern and left [[heart axis]].
Image:12lead_vt2.png|Ventricular tachycardia of 250 bpm with a [[RBBB|right bundle branch block]] pattern and right [[heart axis]].
Image:12lead_vt2.png|Ventricular tachycardia of 250 bpm with a [[RBBB|right bundle branch block]] pattern and right [[heart axis]].
Image:12lead_vt3.png|Ventricular tachycardia of 150 bpm with a [[RBBB|right bundle branch block]] pattern and right [[heart axis]]. Mind the 5th and 6th complex from the right side. These are fusion complexes.
Image:12lead_vt3.png|Ventricular tachycardia of 150 bpm with a [[RBBB|right bundle branch block]] pattern and right [[heart axis]]. Mind the 5th and 6th complex from the right side. These are fusion complexes. Furthermore this ECG shows [[Technical Problems|baseline drift]], which is a technical artefact
Image:12lead_vt4.jpg|Ventricular tachycardia of 145 bpm with a [[RBBB|right bundle branch block]] pattern and left [[heart axis]].
Image:nsvt.png|A non sustained VT of five beats duration
Image:ECG000006.jpg|An example of idiopathic ventricular tachycardia (Belhassen VT)
File:DVA2161.jpg|A biphasic VT in a patient with long QT syndrome
</gallery>
</gallery>
==References==
<biblio>
#segal pmid=17338765
#NSVT pmid=23747767
</biblio>

Latest revision as of 20:33, 25 August 2013

This is part of: Ventricular Arrhythmias
Ventricular Tachycardia (VT or V-tach)
{{{locatieafbeelding}}}
Atrial rate 60-100 bpm
Ventricular rate 110-250 bpm
Regularity regular
Origin ventricles
P-wave AV-dissociation
Effect of adenosine no rate reduction (can accelerate)
Example ECG: An example of a polymorphic ventricular tachycardia Ventricular Tachycardia (VT or V-tach)
Example ECG2: Ventricular tachycardia on a 12 lead recording
Ventricular tachycardia of 140 bpm with a left bundle branch block and a left axis.


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 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 [1].

Ventricular tachycardia can be catechorized as follows:

  • Non-sustained VT: three or more ventricular beats with a maximal duration of 30 seconds.
  • Sustained VT: a VT of more than 30 seconds duration (or less if treated by electrocardioversion within 30 seconds).
  • Monomorphic VT: all ventricular beats have the same configuration.
  • 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 digoxin intoxication and long QT syndrome.

Ventricular tachycardia can be difficult to diagnose when confronted with a wide complex tachycardia. A seperate chapter deals with ECG algorithms to analyze wide complex tachycardias.

Localisation of the origin of a ventricular tachycardia

The localisation of the origin (or exit site) of a ventricular tachycardia can be helpful in understanding the cause of the VT and is very helpful when planning an ablation procedure to treat a ventricular tachycardia. Localisation of the origin of a ventricular tachycardia is discussed in a seperate chapter.

Examples

References

  1. Marine JE, Shetty V, Chow GV, Wright JG, Gerstenblith G, Najjar SS, Lakatta EG, and Fleg JL. Prevalence and prognostic significance of exercise-induced nonsustained ventricular tachycardia in asymptomatic volunteers: BLSA (Baltimore Longitudinal Study of Aging). J Am Coll Cardiol. 2013 Aug 13;62(7):595-600. DOI:10.1016/j.jacc.2013.05.026 | PubMed ID:23747767 | HubMed [NSVT]
  2. Segal OR, Chow AW, Wong T, Trevisi N, Lowe MD, Davies DW, Della Bella P, Packer DL, and Peters NS. A novel algorithm for determining endocardial VT exit site from 12-lead surface ECG characteristics in human, infarct-related ventricular tachycardia. J Cardiovasc Electrophysiol. 2007 Feb;18(2):161-8. DOI:10.1111/j.1540-8167.2007.00721.x | PubMed ID:17338765 | HubMed [segal]

All Medline abstracts: PubMed | HubMed