Ventricular Tachycardia

Question 1

What is VT?

Answer 1

-Originates below the AV node
-Usually (not always) outside normal conduction pathways

=QRS ≥120ms (broad complex)
=Rate >100bpm
=Duration ≥30s
==Or haemodynamic compromise
==Sustained vs non-sustained
==Morph

Question 2

Pathophysiology of VT

Answer 2

-Re-entry (most common)
=Fibrosis/ structural disease!!!
=PVCs (premature ventricular complex)
=BBB

-Automatic
=Ischaemia
=Metabolic disturbance
=Sympathetic tone

-Triggered
=Metabolic disturbance
=Drug toxicity

Question 3

Symptoms of VT

Answer 3

-Asymptomatic
-Palpitations
-Malaise
-Dyspnoea
-Chest pain
-Pre-syncope
-Syncope

Question 4

Signs of VT

Answer 4

-Tachycardia
-Reduced CO (BP, GCS)
-Other
=Fluctuating BP
=Cannon A waves
=Varying S1 intensity

Question 5

What do symptoms and signs of VT depend on?

Answer 5

-Duration
-CO (rate, ventricular function)
-Other disease (CAD, VHD)

Question 6

Investigations of VT

Answer 6

-ECG
-Bloods (electrolytes)
-Angiography (ischaemia)

-Sinus rhythm ECG and bloods
-Myocardial assessment of function/ structure
-Assessment for ischaemia
-Provocative testing/ EP study

Question 7

VT Differentials ECG

Answer 7

-SVT with aberrant conduction, AVRT
=Assume VT unless you know what you are doing
=Algorithms

-Extreme R axis deviation
-AV dissociation= capture beats , fusion beats (atria and ventricles are doing different things)
-Precordial concordance (V1-6)
-Brugada criteria

Question 8

Acute treatment for VT

Answer 8

-ALS
-Directed therapy (electrolytes, coronary angiography for infarct)

Question 9

Chronic treatment of VT

Answer 9

-Ablation
-ICD (implantable cardioverter defib)
-Stereotactic radiation therapy

Question 10

Chronic prevention of VT

Answer 10

-Optimise underlying pathology (treat inducible ischaemia, stop QT prolonging medications)
-Beta blockade