Ventricular Tachycardia (VT) in Singapore: Symptoms, Causes and Treatment

Ventricular tachycardia (VT) is a fast heart rhythm that starts in the ventricles – the heart’s main pumping chambers – rather than in its normal pacemaker. It is a type of arrhythmia (an abnormal heart rhythm) that can range from harmless short bursts to a life-threatening emergency, because a very fast ventricular rhythm can stop the heart pumping effectively. If you or a family member has just been diagnosed with VT, this page explains what it is, its symptoms, why structural heart disease and inherited conditions cause it, and how it is treated with medication, an implantable device or ablation. It is general information and not a substitute for advice from your own doctor.

What Is Ventricular Tachycardia?

Normally each heartbeat begins in the sinus node at the top of the heart and travels down in an orderly way. In ventricular tachycardia, the ventricles generate their own rapid signals – typically 100 to 250 beats per minute – and take over the rhythm. Because the ventricles are beating too fast to fill properly between beats, the heart pumps less blood with each beat.

VT is described by how long it lasts and how it behaves. Non-sustained VT is a short burst of a few beats that stops on its own. Sustained VT lasts longer and can cause collapse. Monomorphic VT has a single, steady pattern and usually comes from a fixed area of scar; polymorphic VT has a constantly changing pattern and is often more dangerous. Sustained VT can deteriorate into ventricular fibrillation and cause sudden cardiac arrest, which is why it is always taken seriously.

Ventricular Tachycardia Symptoms

Symptoms depend on how fast the rhythm is and how well the heart is otherwise working:

• Palpitations – a sudden, fast, pounding heartbeat
• Dizziness or light-headedness
• Breathlessness
• Chest tightness or discomfort
• Near-fainting or fainting (syncope)
• Collapse or loss of consciousness in severe, sustained episodes

Short runs may cause only a flutter or brief dizziness, or no symptoms at all. Fainting during exertion is a particularly important warning sign and should never be dismissed.

When to Seek Emergency Help

Call 995 immediately if someone:

• Collapses and is unresponsive or not breathing normally – begin CPR and send for the nearest AED (automated external defibrillator)
• Has a very fast heartbeat with chest pain, severe breathlessness, or fainting

Sustained VT is a medical emergency. Rapid CPR and defibrillation save lives when a fast ventricular rhythm stops the heart pumping.

Causes and Risk Factors

Most ventricular tachycardia occurs in a heart that has been damaged or is structurally abnormal:

• Scar from a previous heart attack – the most common cause in adults. Scar tissue creates the circuits that drive VT, often years after the original event.
• Cardiomyopathy – heart muscle disease that weakens or thickens the heart raises the risk of dangerous ventricular rhythms.
• Heart failure and significant valve disease
• Inherited conditions – certain channelopathies and inherited cardiomyopathies affect the heart’s electrical system and can cause VT in younger people with structurally normal-looking hearts; these sometimes run in families.
• Other triggers – electrolyte disturbances, some medications and stimulant drugs, and, rarely, VT arising in a normal heart (idiopathic VT), which tends to be more benign.

How Ventricular Tachycardia Is Diagnosed

• Electrocardiogram (ECG) – a resting ECG captures the rhythm if it is present and shows signs of previous heart damage or inherited patterns.
• 24-hour Holter or extended monitor – records the heart over days to catch intermittent runs of VT and link them to symptoms.
• Echocardiogram – an echocardiogram (ultrasound scan of the heart) measures pumping strength and looks for scar, thickening or valve problems; a weakened heart muscle is the strongest predictor of dangerous VT.
• Cardiac MRI – gives detailed images of scar and muscle disease in selected cases.
• Electrophysiological (EP) study – an electrophysiological (EP) study maps the electrical circuits from inside the heart using fine catheters, pinpoints where the VT starts, and often allows treatment by ablation in the same session.
• Genetic testing and family screening – considered when an inherited cause is suspected.

Treatment Options

Treatment aims to stop dangerous episodes and prevent sudden death, while treating the underlying heart condition.

• Treating the underlying disease – managing coronary artery disease, heart failure and cardiomyopathy reduces the tendency to VT. Correcting electrolyte problems and reviewing medications also helps.
• Medication – drug classes such as beta-blockers and anti-arrhythmic drugs are used to suppress episodes and slow the rhythm.
• Implantable cardioverter-defibrillator (ICD) – for people who have survived a dangerous VT or are at high risk (for example, those with a significantly weakened heart muscle), an ICD continuously monitors the rhythm and automatically delivers a shock or rapid pacing to stop a life-threatening arrhythmia. Our cardiac pacemakers and devices service explains what implantation involves.
• Catheter ablation – a keyhole procedure that targets and destroys the small area of heart tissue driving the VT. It can reduce the frequency of episodes and ICD shocks, and is sometimes used as a main treatment for VT in an otherwise normal heart.

When to See a Cardiologist

See a cardiologist promptly if you have had palpitations with dizziness or fainting, have fainted during exertion, have known heart disease with a fast heart rhythm, or have a family history of sudden unexplained death or inherited heart conditions. Ventricular tachycardia can be the first sign of a serious underlying problem, and early assessment allows protective treatment before an emergency happens.

Frequently Asked Questions

Is ventricular tachycardia life-threatening?

It can be. Short, non-sustained runs may be relatively benign, but sustained VT can stop the heart pumping effectively and deteriorate into cardiac arrest. Because it is difficult to predict, VT is always assessed carefully and often treated to prevent sudden death.

What causes ventricular tachycardia?

Most cases arise in a heart damaged by a previous heart attack or weakened by cardiomyopathy, where scar tissue creates abnormal electrical circuits. Less commonly it results from inherited electrical conditions, electrolyte problems, or certain medications, and occasionally it occurs in a structurally normal heart.

Can ventricular tachycardia be cured?

Some forms, particularly VT in a structurally normal heart, can be effectively cured by catheter ablation. When VT arises from underlying heart disease, treatment focuses on controlling episodes with medication and protecting against sudden death with an ICD, alongside treating the underlying condition.

What is the difference between VT and SVT?

SVT arises above the ventricles and is rarely life-threatening in a normal heart. Ventricular tachycardia arises in the pumping chambers themselves, usually in a damaged heart, and is far more dangerous – which is why it is investigated and treated more aggressively.

Can you live a normal life with ventricular tachycardia?

Many people do, particularly once the underlying heart condition is treated and, where needed, an ICD is in place to protect against dangerous episodes. Regular follow-up, taking medication as prescribed, and managing heart disease risk factors all help.