Life-Threatening Ventricular Arrhythmia
Ventricular Fibrillation
Ventricular fibrillation is a life-threatening rhythm in which the lower chambers of the heart quiver instead of pumping. It requires emergency treatment, and what follows is careful assessment and prevention of recurrence.
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Understanding VF
What Is Ventricular Fibrillation?
In ventricular fibrillation (VF) the electrical activity of the ventricles becomes rapid and completely disorganised. The ventricles are the main pumping chambers, and when they quiver rather than contract in a coordinated way, the heart can no longer move blood effectively around the body.
Within seconds the person loses consciousness, and without immediate resuscitation and defibrillation VF leads to cardiac arrest. For this reason VF is treated as a medical emergency, not as a condition to be monitored at home.
VF is different from the more common, usually benign rhythm complaints such as occasional extra beats. Its importance lies in how quickly it must be recognised and treated, and in the work that follows to find out why it happened.
Context
How VF Relates to Ventricular Tachycardia
Ventricular tachycardia (VT) is a fast but organised rhythm from the ventricles. Some forms are tolerated for a period, others cause collapse. VT can on occasion degenerate into VF, which is one reason sustained VT is taken seriously.
Both rhythms belong to the group of ventricular arrhythmias. Our VT page and the ventricular arrhythmias overview explain the wider picture.
The distinction matters because the response differs. VF has no effective pulse and needs immediate defibrillation. VT may allow time for medication, cardioversion or planned catheter ablation, depending on how the person is affected.
Premature ventricular beats are a separate and far more common finding. In a heart without other disease they are usually not a sign of impending VF; see PVCs.
Why It Happens
Conditions Associated With VF
VF usually occurs when the heart is vulnerable because of an underlying problem. Identifying that problem is the central task after an episode.
Coronary artery disease
Reduced blood supply, an acute heart attack or scarring from a previous one can create unstable electrical conditions in the ventricle.
Cardiomyopathy
Diseases of the heart muscle, including those with weakened pumping function, can predispose to dangerous ventricular rhythms.
Inherited electrical conditions
Some people have a structurally normal heart but an inherited disturbance of electrical function, such as Brugada syndrome or long QT syndrome.
Metabolic and drug-related causes
Severe electrolyte disturbances and certain medicines or substances may provoke ventricular rhythm disturbance in susceptible people.
Idiopathic VF
In a minority of survivors no cause is found after a full work-up. This is managed with careful long-term follow-up.
Triggering premature beats
In selected patients, repeated premature beats from a specific site can trigger VF and may be a target for ablation.
This list is illustrative and not a self-diagnosis tool. Only a physician can determine the cause in an individual patient.
Emergency Response
Recognising and Responding to Cardiac Arrest
VF is not an appointment-based problem. If someone suddenly collapses, is unresponsive and not breathing normally, act at once.
Call emergency services
Call your local emergency number immediately and say that the person is unresponsive and not breathing normally.
Start chest compressions
Push hard and fast in the centre of the chest without interruption until help arrives. Training in basic life support saves lives.
Use a defibrillator
If an automated external defibrillator is available, switch it on and follow its voice instructions. It analyses the rhythm and advises whether a shock is needed.
Continue until help takes over
Do not stop unless the person recovers or trained responders take over.
Palpitations, dizziness or fainting that you have experienced yourself should be assessed promptly. Fainting during exercise or without warning deserves urgent medical review.
After an Episode
Assessment After Survival
A person who has survived VF, or who is at suspected risk, is assessed in a structured way. The aim is to understand the cause and decide on protection against recurrence.
12-lead ECG, telemetry and any available recordings of the event.
Imaging of the heart
Echocardiography and, where appropriate, further imaging to assess structure and function.
Coronary assessment
Evaluation for coronary artery disease or spasm when clinically indicated.
Blood tests
Electrolytes and other laboratory markers, plus review of all medicines.
In selected patients, invasive study may help identify triggers or substrate.
When an inherited condition is suspected, relatives may need evaluation.
Protection
Preventing Recurrence
Management is individualised. It generally combines treatment of the underlying cause with protection against a further event.
Treat the cause
Revascularisation, heart failure therapy or correction of metabolic problems where these apply.
Medication
Certain anti-arrhythmic or heart-protective medicines may be used in selected patients.
ICD
An implantable defibrillator monitors the rhythm and can deliver treatment if a dangerous ventricular rhythm occurs.
Catheter ablation
In selected cases ablation may target VT substrate or a trigger site, usually alongside other protection.
An ICD does not prevent VF from starting; it treats it. Ablation does not replace an ICD in patients who need one. The right combination is decided individually.
Long-Term
Follow-Up and Everyday Life
After VF, regular follow-up is part of care. Devices are checked at intervals, medicines are reviewed and the underlying condition is monitored.
Advice about physical activity, driving, work and travel depends on the cause, the treatment chosen and the local rules that apply. These decisions are individual and should be discussed with your electrophysiologist.
Close family members may be offered screening when an inherited condition is possible.
Questions
Frequently Asked Questions
Is ventricular fibrillation the same as atrial fibrillation?
Can VF stop by itself?
Can someone live a normal life after VF?
Do all survivors need an ICD?
Should my relatives be tested?
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