Ventricular Tachycardia (VT)
Ventricular tachycardia (VT) is a fast rhythm arising from the ventricles. It can be benign (especially some idiopathic VTs), but it can also be life-threatening and associated with sudden cardiac death, particularly when there is structural heart disease.
Educational Videos
1. Key Definitions
- Non-sustained VT (NSVT): ≥3 ventricular beats, lasting <30 seconds, terminates spontaneously.
- Sustained VT: lasts ≥30 seconds OR causes haemodynamic instability requiring intervention.
- Monomorphic VT: consistent QRS shape (often scar-related re-entry).
- Polymorphic VT: varying QRS morphology; includes torsades de pointes (QT-related).
2. Why VT Matters
- Can cause syncope, collapse, or cardiac arrest.
- May indicate underlying cardiomyopathy, prior myocardial infarction scar, myocarditis, or inherited arrhythmia syndromes.
- Persistent fast VT can cause tachycardia-induced cardiomyopathy.
3. Causes
A. Structural Heart Disease (higher risk)
- Prior myocardial infarction / coronary artery disease (scar-related VT)
- Heart failure / dilated cardiomyopathy
- Hypertrophic cardiomyopathy
- Arrhythmogenic right ventricular cardiomyopathy (ARVC)
- Myocarditis / cardiac sarcoidosis
- Valvular heart disease
B. Idiopathic VT (often lower risk)
- Right ventricular outflow tract (RVOT) VT
- Fascicular (verapamil-sensitive) VT
- Outflow tract ectopy / bigeminy leading to VT episodes
C. Electrical / Metabolic Triggers
- Electrolyte abnormalities (low K/Mg)
- Drug effects (QT prolongation → torsades)
- Ischaemia
- Stimulants
4. Symptoms
- Palpitations
- Dizziness or presyncope
- Syncope
- Chest pain
- Shortness of breath
- Collapse / cardiac arrest (severe cases)
5. ECG: VT vs SVT with Aberrancy
A fast wide-complex tachycardia should be treated as VT until proven otherwise, particularly in older patients or those with known heart disease.
- VT is more likely with prior MI / cardiomyopathy, very wide QRS, AV dissociation, capture/fusion beats.
- SVT with bundle-branch block can mimic VT.
- When uncertain clinically: manage as VT (safer).
6. Investigations
- 12-lead ECG during symptoms (best)
- Holter / event monitor / implantable loop recorder
- Echocardiogram (LV function, structural disease)
- Cardiac MRI (scar, myocarditis, ARVC patterns)
- Bloods: electrolytes, thyroid (selected), troponin if ischaemia suspected
- Coronary assessment if ischaemia suspected
- EP study in selected cases
7. Acute Management
If unstable (hypotension, chest pain, pulmonary oedema, altered consciousness)
- Immediate synchronized cardioversion
- CPR + defibrillation if pulseless VT/VF
If stable
- Correct electrolytes, treat ischaemia
- Antiarrhythmics (protocol-dependent): amiodarone, procainamide, lidocaine (often used in specific scenarios)
- Urgent specialist review
8. Long-Term Treatment
A. Treat the underlying cause
- Optimize heart failure therapy
- Revascularize if ischaemia-related
- Stop QT-prolonging drugs if torsades risk
- Correct electrolytes
B. Medications
- Beta blockers are foundational in many structural-heart VT scenarios.
- Amiodarone / sotalol may reduce VT burden but have risks and require monitoring.
C. ICD (Implantable Cardioverter-Defibrillator)
ICDs prevent sudden death by detecting and terminating VT/VF. They are used for:
- Secondary prevention: after sustained VT/VF or cardiac arrest (in appropriate candidates).
- Primary prevention: in selected high-risk cardiomyopathy / low EF groups.
D. Catheter Ablation
- Scar-related VT ablation can reduce recurrent VT/ICD shocks, sometimes requires repeat procedures.
- Idiopathic VT ablation (e.g., RVOT, fascicular) is often highly successful and may be curative.
| VT Context | Typical Ablation Outcome |
|---|---|
| Idiopathic (RVOT/fascicular) | Often high success; many patients become VT-free |
| Scar-related VT (post-MI/cardiomyopathy) | Reduces VT burden/ICD shocks; recurrence possible |
9. Prognosis & Life Expectancy
Prognosis depends mainly on whether VT occurs in a structurally normal heart or with significant underlying heart disease.
| Scenario | Typical Risk Profile | What Most Improves Outcomes |
|---|---|---|
| Idiopathic VT (normal structure) | Often low mortality risk; symptoms can be severe | Ablation when recurrent; avoid triggers; follow-up |
| VT with cardiomyopathy / low EF | Higher risk of sudden death and heart failure progression | HF optimisation, ICD when indicated, ablation to reduce VT burden |
| VT during acute ischaemia / MI | High short-term risk | Urgent reperfusion + ICU management |
Leaving VT untreated (or leaving the heart rate persistently high) can worsen heart function over time.
10. When to Seek Emergency Help
- Fainting or near-fainting
- Severe chest pain or breathlessness
- Very fast pulse with low blood pressure symptoms
- Any episode of collapse
References (Open Access)
- ESC Guidelines on ventricular arrhythmias and prevention of sudden cardiac death (open access guideline).
- AHA/ACC/HRS guidance on ventricular arrhythmias / SCD prevention (open sections vary by publication).
- Key reviews and trials on ICD therapy, VT ablation, and arrhythmic risk stratification (open-access sources to be curated to match your site’s reference style).
Compare with: SVT | Atrial Fibrillation | Atrial Flutter
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