Overview
Ventricular tachycardia (VT) is a broad complex tachycardia that originates from a ventricular ectopic focus. It is defined as 3 or more consecutive beats at a rate of >100 bpm. It requires urgent treatment as it can lead to ventricular fibrillation and cardiac arrest.
It can further be defined as:
- Sustained VT – VT that continues for more than 30 seconds or leads to haemodynamic instability within 30 seconds requiring intervention
- Non-sustained VT – VT that lasts <30 seconds and does not cause haemodynamic instability
Types of ventricular tachycardia
VT can also be divided based on QRS morphology into:
- Monomorphic VT:
- Stable SQRS morphology with no variation between beats
- Most commonly caused by myocardial infarction
- Polymorphic VT:
- QRS morphology changes with each beat
- A subtype of polymorphic VT is torsades de pointes.
Presentation
- Palpitations
- Breathlessness
- Chest pain or tightness
- Anxiety
- Dizziness
- Syncope
- Fatigue
Some patients may present with haemodynamic instability. These patients need urgent emergency care:
- Acute heart failure:
- Shortness of breath
- Crackles on auscultation
- Elevated jugular venous pressure
- Cardiogenic shock:
- Tachycardia (>150 bpm) and hypotension (systolic blood pressure <90 mmHg)
- Syncope/pre-syncope
- Cardiac chest pain and shortness of breath
Investigations
- ECG:
- Rate >100 bpm
- Wide QRS complexes (>120 ms)
- Atrioventricular dissociation
Figure 1: An ECG showing monomorphic ventricular tachycardia
Management
Haemodynamically unstable
- Manage as per the Resuscitation Council UK Tachycardia guidelines. These are discussed in Adult Tachycardia.
Haemodynamically stable
- IV amiodarone through a central line
- Other options include lidocaine and implantable cardioverter-defibrillators
