Ventricular tachycardia

• Is a broad complex tachycardia
• Most commonly mechanism is a re-entry pathway, usually caused by scar tissue (MI)
• It has the potential to precipitate ventricular fibrillation and hence requires urgent treatment.

Two main types of VT

• Mono-morphic VT
  • Most commonly caused by myocardial infarction
• Polymorphic VT
  • A subtype of polymorphic VT is torsades de pointes which is precipitated by prolongation of the QT interval

Causes of prolonged QT

• Congenital 👶🏼
  • Jervell-Lange-Nielsen syndrome (includes deafness and is due to an abnormal potassium channel)
  • Romano-Ward syndrome (no deafness)
• Drugs 💊
  • Amiodarone
  • Sotalol
  • Class 1a - antiarrhythmic drugs
  • TCAs
  • Fluoxetine
  • Chloroquine
  • Terfenadine
  • Erythromycin
• Other
  • Hypocalcaemia
  • Hypokalaemia - most important
  • Hypomagnesaemia
  • Acute MI
  • Myocarditis
  • Hypothermia
  • Subarachnoid haemorrhage

Management

Overview

Remember VT can present both with or without a pulse.

• If pulseless, the patient is in cardiac arrest, and you should follow the cardiac arrest algorithm, in which pulseless VT is a shockable rhythm
• If the patient has a pulse, you should follow the tachyarrhytmia algorithm
  • VT is a regular broad complex tachycarydia

Pulseless

<aside> 💡 No pulse → defibrillate → CPR

</aside>

Four Cardiac Arrest Rhythms

Has a Pulse