QuestionSBA
QuestionChoice
SVT, by definition, originates from _above_ the ventricles - as a result, it is a **narrow** complex tachycardia - conduction in the ventricles is by the usual mechanism
33270
c
Supraventricular tachycardia (SVT)
QuestionChoice
Polymorphic ventricular tachycardia (otherwise known as _torsades de pointes_) has a characteristic twisting of the QRS complexes around the baseline, compared to monomorphic VT in which each complex is very homogenous to the next
33272
e
Polymorphic ventricular tachycardia
QuestionChoice
Though VF is a broad complex tachycardia, this rhythm is too regular in morphology to represent VF. VF is caused by chaotic and uncoordinated electrical activity in the ventricles and as such produces an irregular rhythm with broad QRS complexes of differing amplitudes
33269
b
Ventricular fibrillation (VF)
QuestionChoice
ECG findings in monomorphic VT show wide QRS complexes at a rate of ≥100bpm. This rhythm originates in the ventricles, meaning no P waves are present (indicating the absence of atrial conduction) and often runs very fast, with no discernible ST segment or T wave. If VT occurs without a pulse, it is a shockable rhythm in the resuscitation. If VT occurs with a pulse, this is a peri-arrest rhythm and requires urgent assessment and treatment to stabilise the patient
33268
a
Monomorphic ventricular tachycardia (VT)
QuestionChoice
At this time in the stem it is not certain if the patient has a pulse; therefore we could not name any ECG trace accurately as PEA
33271
d
Pulseless electrical activity (PEA)
QuestionComment
Rhythm check
26521
User
subscriber
Metabolism Myopathy
Concept
Chapter
# Summary 

Broad complex tachycardia refers to dysrhythmias with a heart rate greater than 100 beats per minute and a QRS complex broader than 120 milliseconds. This term encompasses life-threatening rhythms such as ventricular tachycardia (VT) and ventricular fibrillation (VF). VT is a regular, broad complex tachycardia and may be with or without a pulse. In contrast, VF is irregular and is always pulseless. Pulseless VT and VF must be managed according to the ALS algorithm and require immediate defibrillation and administration of medications like adrenaline and amiodarone, whilst managing pulsed VT involves synchronised shocks and amiodarone. SVT with aberrancy, a condition where supraventricular tachycardia occurs in the presence of bundle-branch block, can mimic VT and should be treated cautiously.

# Definition 

Broad complex tachycardias are dysrhythmias that have a heart rate greater than 100bpm and a QRS complex that is greater than 120ms. The most common broad complex tachycardias are ventricular tachycardia or ventricular fibrillation. 

# Ventricular Tachycardia (VT)

A regular broad complex tachycardia. It can occur with a pulse or it may be pulseless. 

ECG features include: 

* Tachycardia (>100 beats per minute)
* Absent p waves
* Monomorphic regular broad QRS complexes (>120ms)

[lightgallery]

# Management of VT 

## Pulseless VT 

If there is no pulse the patient should be managed according to the Advanced Life Support algorithm. 

* Pulseless VT is a shockable rhythm so a 200J bi-phasic **unsynchronised** shock should be administered. 
* IV adrenaline (1mg of 10ml 1:10,000 solution) and IV amiodarone (300mg) should be administered after delivery of the 3rd shock.
* Adrenaline should be administered every 3-5 minutes thereafter.  

## Pulsed VT with Adverse Features

If the patient has a pulse but is demonstrating adverse features (shock, syncope, myocardial ischaemia, or heart failure) the patient should be managed according to Resuscitation Council Tachyarrhythmia algorithm. 

* Administer synchronised DC shocks (up to 3 attempts). If the patient is conscious this will require sedation or anaesthesia. 
* Expert help should guide amiodarone administration (300mg IV over 10-20 minutes followed by 900mg infusion over 24 hours). 

## Pulsed VT with No Adverse Features 

If the patient has a pulse and is not demonstrating adverse features then the Resuscitation Council Tachyarrhythmia algorithm should be followed. 

* Amiodarone 300mg IV over 10-60 minutes. 
* If this is ineffective then administer synchronised DC shocks (up to 3 attempts). If the patient is conscious this will require sedation or anaesthesia. 
* *N.B. if there has been a previous certain diagnosis of SVT with aberrancy treat as for regular narrow complex tachycardias*

# Ventricular fibrillation (VF) 

An irregular broad complex tachycardia. This is always a pulseless rhythm.

ECG features include: 

* Tachycardia >100bpm 
* QRS complexes are polymorphic and irregular (>120ms)

[lightgallery1]

# Management of VF

The patient should be managed according to the Advanced Life Support algorithm. 

* VF is a shockable rhythm so a 200J bi-phasice **unsynchronised** shock should be administered. 
* IV adrenaline (1mg of 10ml 1:10,000 solution) and IV amiodarone (300mg) should be administered after delivery of the 3rd shock.
* Adrenaline should be administered every 3-5 minutes thereafter.

# Other Broad Complex Tachycardias 

Include: 

* Torsades des pointes: see section. 
* SVT with aberrancy: occurs when a patient with a bundle-branch block goes into SVT. It can be difficult to distinguish between VT and an SVT with aberrancy. The safest approach is to treat as VT. 

[lightgallery2]

# NICE Guidelines

[NICE CKS Guidelines for Cardiac Arrest and ALS](<https://cks.nice.org.uk/topics/cardiac-arrest-out-of-hospital-care/management/advanced-life-support-adult/>)

# References
[Resuscitation Council UK Adult Tachycardia Algorithm](<https://www.resus.org.uk/sites/default/files/2021-04/Tachycardia%20Algorithm%202021.pdf>)

[Resuscitation Council UK Adult ALS Algorithm](<https://www.resus.org.uk/sites/default/files/2021-04/Adult%20Advanced%20Life%20Support%20Algorithm%202021.pdf>)
613
Picture
151
ventricularFibrillation.png
images/xtspeo851548088453325.jpg
images/xtspeo851548088453325_256.jpg
images/xtspeo851548088453325_512.jpg
NygCBICJhomAZ4hxd2BthvA6GA==
Topic
59
ECG Interpretation
Picture
380
Ventricular tachycardia.png
images/5ndmzlp31639016754969.jpg
images/5ndmzlp31639016754969_256.jpg
images/5ndmzlp31639016754969_512.jpg
OQgCA4D0xmmFebhoAAAAAAA=
Topic
35
Cardiology
Picture
Torsade de pointes on an ECG.
724
Torsades de pointes.png
images/qj5w8ria1665036171704.jpg
images/qj5w8ria1665036171704_256.jpg
images/qj5w8ria1665036171704_512.jpg
NigCBICBz0xVeZqZZoh2fwPVVQ==
3429
Broad Complex Tachycardia
Topic
59
ECG Interpretation
6654
Picture
376
VT ECG.png
images/4yr16el01639016716185.jpg
images/4yr16el01639016716185_256.jpg
images/4yr16el01639016716185_512.jpg
NUgCAoCHh3eIh/h3CXZp8qk=
Topic
35
Cardiology
A 30 year old man has a cardiac arrest whilst playing rugby and is brought into the emergency department (ED) by ambulance. Cardiopulmonary resuscitation (CPR) is ongoing and it is time for a rhythm check.

Which rhythm can be identified on this ECG trace?

[lightgallery]
a