Ventricular Tachycardia (VT): ECG Features, Types & Treatment

Ventricular tachycardia is a fast, wide-complex rhythm from the ventricles that can be life-threatening. Here's how to recognise it on the ECG, tell it from SVT, and treat it fast.

What is ventricular tachycardia?

Ventricular tachycardia (VT) is three or more consecutive beats arising from the ventricles at a rate above 100 bpm, producing a wide-complex tachycardia. Because the impulse starts below the AV node and spreads slowly through muscle rather than the fast conduction system, the QRS is wide (≥ 0.12 s). VT can be brief and self-limiting or degenerate into ventricular fibrillation and cardiac arrest.

ECG features

• Wide QRS (≥ 0.12 s)
• Rate usually 100–250 bpm
• Regular (monomorphic) or varying (polymorphic)
• No consistent P waves; AV dissociation, capture beats, and fusion beats favour VT

Ground the basics in our ECG interpretation guide.

Monomorphic vs polymorphic VT

Type	QRS shape	Typical cause
Monomorphic	Uniform, beat to beat	Scar from prior MI or cardiomyopathy
Polymorphic	Continuously changing	Ischaemia; with a long QT it is torsades de pointes

VT is also classed as sustained (lasting > 30 seconds or causing collapse) or non-sustained. Torsades is covered in our QT interval guide.

VT vs SVT with aberrancy

A wide, regular tachycardia is either VT or a supraventricular tachycardia conducted with aberrancy — and getting it wrong is dangerous. The safe rule: treat a wide-complex tachycardia as VT until proven otherwise, especially in anyone with known heart disease. Features favouring VT include AV dissociation, very wide QRS, fusion/capture beats, and an extreme axis.

Causes

• Coronary artery disease and prior myocardial infarction (scar) — the commonest
• Cardiomyopathy and heart failure
• Electrolyte disturbance (low potassium or magnesium)
• Long QT syndrome and certain drugs (polymorphic VT / torsades)
• Inherited channelopathies

Treatment

Management hinges on whether there's a pulse and whether the patient is stable:

Situation	Treatment
Pulseless VT	Immediate defibrillation + CPR (a shockable arrest rhythm)
Unstable VT with a pulse	Synchronised cardioversion
Stable VT	Antiarrhythmics — amiodarone, procainamide, or lidocaine
Torsades de pointes	Intravenous magnesium

For recurrent VT, an implantable cardioverter-defibrillator (ICD) and sometimes catheter ablation are used to prevent sudden death.

Key takeaways

• VT is a wide-complex tachycardia from the ventricles at > 100 bpm.
• Monomorphic is usually scar-related; polymorphic with a long QT is torsades.
• Treat a wide, regular tachycardia as VT until proven otherwise.
• Pulseless VT → defibrillate; unstable → cardiovert; stable → antiarrhythmics.
• An ICD prevents sudden death in recurrent VT.

Frequently asked questions

What is ventricular tachycardia?

A fast heart rhythm of three or more consecutive beats from the ventricles at over 100 bpm, producing a wide-complex tachycardia that can be life-threatening.

How do you recognise VT on an ECG?

A wide QRS (≥0.12 s), a rate of 100–250 bpm, a regular or varying rhythm with no consistent P waves, and features such as AV dissociation, capture, or fusion beats.

What is the difference between monomorphic and polymorphic VT?

Monomorphic VT has a uniform QRS (usually from scar) and polymorphic VT has a continuously changing QRS; polymorphic VT with a long QT is torsades de pointes.

How do you tell VT from SVT with aberrancy?

Both are wide and regular, so treat a wide-complex tachycardia as VT until proven otherwise, especially with known heart disease. AV dissociation and fusion/capture beats favour VT.

How is ventricular tachycardia treated?

Pulseless VT is defibrillated; unstable VT with a pulse is cardioverted; stable VT is treated with antiarrhythmics like amiodarone; torsades is treated with magnesium.

Is ventricular tachycardia an emergency?

It can be. Pulseless VT is a cardiac-arrest rhythm needing immediate defibrillation, and even VT with a pulse can deteriorate quickly.