Ventricular tachycardia (VT) is a potentially life-threatening arrhythmia originating in the cardiac ventricles. VT usually results from underlying cardiac diseases, such as myocardial infarction or cardiomyopathy, but it can also be idiopathic or caused by drugs and electrolyte imbalances. Clinical manifestations range from palpitations and syncope to cardiogenic shock and sudden cardiac death (SCD). The characteristic ECG findings of VT are wide QRS complexes (> 120 ms), tachycardia (≥ 100/minute), and signs of AV dissociation. In the acute setting, management of VT may require immediate cardioversion, defibrillation, or administration of antiarrhythmic drugs. Most patients who develop symptomatic, recurrent VT require long-term therapy involving antiarrhythmic medication, cardioverter-defibrillator implantation, or catheter ablation of the arrhythmogenic focus. Torsades de pointes (TdP) is a type of polymorphic VT occurring in patients with a prolonged QT interval. Intravenous magnesium sulfate and correction of the underlying etiology of prolonged QTc are important aspects of TdP management.
Ventricular tachycardia: ≥ 3 consecutive ventricular complexes (wide QRS complex) at a frequency of ≥ 100/minute
- Classification by duration
- Classification by morphology
- Premature ventricular complex : ≤ 3 consecutive ventricular complexes often followed by a complete compensatory pause
- Electrical storm: ≥ 3 episodes of sustained tachycardia or defibrillations within 24 hours
Cardiac causes 
- Cardiac scars: secondary to myocardial infarction or cardiac surgery
- Myocardial ischemia: secondary to angina
- Inflammatory causes: myocarditis, endocarditis, or rheumatic heart disease
- Idiopathic: areas of increased automaticity in a structurally normal heart
- Nonischemic cardiomyopathy (CM)
Inherited arrhythmia syndromes (channelopathies)
- A group of genetic syndromes caused by mutations in genes that encode cardiac ion channels resulting in a predisposition for arrhythmias 
- Can lead to sudden cardiac death if uncontrolled
- Examples: Congenital long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia (CPVT)
Extracardiac causes 
- Certain drugs 
Drug-induced toxicity and electrolyte abnormalities are the most common extracardiac causes of ventricular tachycardia.
Monomorphic VT (similar QRS complexes)
- Increased automaticity
- Reentry circuit
- Polymorphic VT (dissimilar QRS complexes): abnormal ventricular repolarization (e.g., due to , drug toxicity, electrolyte abnormalities)
- Asynchronous atrial and ventricular beats and rapid ventricular rhythm → ↓ blood flow into the ventricle during diastole → ↓ cardiac output
- Consequent hemodynamic compromise → symptoms of syncope, MI, angina
- Often asymptomatic, especially in NSVT
- Cardiovascular features
- Symptoms may be unprovoked or exacerbated by physical and/or emotional triggers (e.g., exercise, anger). 
- See “ ” for detailed instructions on the initial evaluation of a tachyarrhythmic patient.
- Urgently consult cardiology.
- Assess for hemodynamic stability and .
Hemodynamically unstable patients
- Pulseless VT: Commence CPR while preparing to defibrillate (see “ACLS” for details).
- VT with pulse
- Deterioration to ventricular fibrillation: Defibrillation and CPR (managed the same as pulseless VT)
- Stable patients
Further management (once stabilized)
- Evaluate for an underlying cause (see “Diagnostics”).
- Consider long-term management (see “Treatment”).
- Ongoing sustained VT: Obtain an ECG to differentiate between ventricular and supraventricular tachycardia (SVT).
- Previous episodes of suspected or confirmed (resolved) VT
An ECG should be obtained in all patients with suspected VT (ongoing or resolved). In an unstable patient, a rhythm strip allows for rapid assessment and initiation of emergency measures. In all stable or stabilized patients, a 12-lead ECG is essential for a detailed evaluation.
Characteristic findings during VT
- Rate: ≥ 100/minute
- Rhythm: typically regular 
- QRS complexes
Signs of AV dissociation 
- Dissociated P waves
- Fusion complexes
- Capture beats (seen occasionally)
In wide-complex tachycardia, signs of AV dissociation help distinguish between VT (AV dissociation present) from SVT with aberrancy (AV dissociation absent). See “Brugada criteria” for further information.
Findings during sinus rhythm
- May be normal
- Features of the underlying cause may be seen, such as:
- Indications: all patients with confirmed VT to assess LVEF and evaluate for structural cardiac defects 
- Findings: Variable; may include valvular defects, regional wall motion abnormalities, ↓ LVEF, and evidence of myocardial infiltration, scarring, or inflammation.
Further assessment of suspected arrhythmia 
- Exercise stress test: Consider if there is suspicion for VT provoked by stress/exertion (e.g., CPVT)
- Ambulatory ECG monitoring (Holter monitor or cardiac event recorder)
- Coronary angiography
- Undifferentiated tachycardia: See “ .”
- Wide-complex tachycardias
If there is any doubt regarding the diagnosis, assume VT rhythm and treat accordingly.
The differential diagnoses listed here are not exhaustive.
- Ongoing or sustained VT: See “Initial management of VT” section above for emergency measures.
Nonsustained VT or resolved sustained VT
- Evaluate for a reversible cause (see “Etiology” and “Diagnostics” sections).
- Reversible cause identified
- Correct any electrolyte imbalances
- Stop .
- Consider digoxin immune fab (fragment antigen-binding) for digoxin toxicity.
- Treat underlying myocardial ischemia if present (see “Treatment of acute coronary syndrome” for details).
- No identifiable reversible cause or recurrent VT
Long-term management of patients with VT
Pharmacological therapy (antiarrhythmics) is often used alongside device therapy (e.g., ICD) to minimize symptoms, risk of recurrence, and risk of sudden cardiac death. Ablation of the arrhythmogenic foci is potentially curative.
Pharmacological therapy 
- β-blockers are typically used as first-line therapy because they reduce the risk of sudden cardiac death.
- Other medications (e.g., class Ic antiarrhythmics or class III antiarrhythmics) may be combined with β-blockers if symptoms persist.
|Medications to minimize VT recurrence |
|Safe in known heart disease||β-blockers|
|Caution in known heart disease|
|Class Ic antiarrhythmics|
|Calcium channel blockers|
Indications for a permanent ICD : all of the following criteria are met 
- Expected survival > 1 year
- Recurrent VT despite treatment of reversible causes
- One or more of the following:
- Radiofrequency catheter ablation
- Surgical ablation
Subtypes and variants
Torsades de pointes (TdP) 
- Definition: : a type of polymorphic VT occurring in patients with a prolonged QT interval
- Clinical features: similar to
- Laboratory and imaging studies: same as for VT (see “Diagnostics”)
- Characteristic ECG findings include: 
- Acute management
- Hemodynamically unstable patients: Defibrillation plus CPR.
- Hemodynamically stable patients: Administer IV magnesium sulfate. 
- Identify and treat the underlying .
- Long-term management 
- Refer to cardiology for a comprehensive evaluation and management.
- Consider β-blockers to minimize the risk of sudden cardiac death (see “Long-term pharmacotherapy in VT” for details).
- Persistent prolonged QT interval despite β-blocker therapy: Consider ICD implantation (with pharmacotherapy) or left cardiac sympathetic denervation.
- Congenital LQTS: See “Treatment” in “Long QT syndrome.”
- Acute management
- Complications: can progress to life-threatening ventricular fibrillation 
We list the most important complications. The selection is not exhaustive.
Acute management checklist for sustained VT
- Assess for hemodynamic stability and signs of unstable tachycardia.
- Obtain an ECG (rhythm strip in unstable patients; 12-lead ECG in stable patients).
- Urgently consult cardiology.
- See “Approach to tachycardia” for detailed instructions on the initial evaluation of a tachyarrhythmic patient.
Hemodynamically unstable patients
- Pulseless VT or VF: Commence CPR while preparing to defibrillate (see “ACLS” for details).
- VT with pulse: See “Management of unstable tachycardia with a pulse” for details.
Hemodynamically stable patients
- See “Management of stable wide-complex tachycardia” for details.
- Attempt pharmacological conversion
- Persistent VT: Perform electrical cardioversion under procedural sedation