VT (1*)

Question 1

What is it?
→ What are the other types similar to this?

Why is it a problem?
→ When does it become life-threatening?

What are the complications?

Answer 1

➊ Type of broad complex tachycardia characterised by 3 consecutive wide QRS complexes at a rate of >100bpm
→ Torsades de Pointes (TdP) and Supraventricular tachycardia (SVT)

➋ Ventricles beat too fast, so heart doesn’t pump enough blood around the body
→ When sustained as it lowers the BP, resulting in light-headedness and syncope

➌ • VF
• Cardiac arrest

Question 2

How is it classified by Morphology?

How is it classified by Duration?

Answer 2

➊ • Monomorphic VT - QRS complexes similar in all beats, indicating a single arrhythmogenic focus
‣ Causes include MI, RV outflow tract
• Polymorphic VT (aka Torsades de Pointes) - QRS complexes vary in each beat, indicating multiple arrhythmogenic foci
‣ Causes include those leading to Prolonged QT

➋ • Non-sustained VT (NSVT) - lasts < 30 secs w/spontaneous termination
• Sustained VT (VT) - lasts > 30secs, causing haemodynamic instability

Question 3

What are its causes?

How does it present?

Which investigations should be done?

How is it managed?

Answer 3

➊ • Structural heart disease e.g. post-MI
• Electrolyte imbalances e.g. hypokalaemia
• Prolonged QT syndrome e.g. drug-induced w/erythromycin

➋ • Often asymptomatic
• Palpitations
• Light-headedness
• SOB
• Sudden cardiac arrest if complicated

➌ • ECG
• Cardiac Imaging (Echo, MRI, CT, Angio) - check for structural defects

➍ • Synchronised DC cardioversion if unstable
• IV Amiodarone if stable
• ICD - Used to terminate episodes of VT and prevent sudden cardiac arrest
• Ablation