Ventricular Fibrillation (VFib): Symptoms and Causes

Ventricular fibrillation (VFib) is a life-threatening arrhythmia in which the lower chambers (ventricles) of your heart tremble and cannot pump blood to your body. VFib is the most serious arrhythmia that requires emergency intervention because it usually leads to sudden cardiac arrest and loss of consciousness. This condition results from irregular and chaotic electrical signals generated in your heart. It usually results in death if not intervened quickly.

What is ventricular fibrillation?

Ventricular fibrillation is a condition where the lower chambers (ventricles) of your heart start trembling due to random and rapid electrical signals. Normally, your heart contracts in a regular and coordinated manner, pumping blood to the body. In ventricular fibrillation, however, the ventricles only tremble instead of contracting due to chaotic signals coming from multiple points in the electrical system of your heart’s lower chambers. This condition is caused by the irregular spread of electrical signals. Heart rate can exceed 300 beats per minute in this condition, but since these beats do not perform a pumping function, your pulse cannot be taken.

What are the symptoms of ventricular fibrillation?

Ventricular fibrillation usually occurs suddenly and progresses with obvious symptoms. Patients lose consciousness within a few seconds due to sudden cardiac arrest. The most obvious symptoms of this condition are absence of pulse, cessation of breathing, loss of consciousness, and fainting.

VFib may sometimes give warning symptoms such as palpitations, chest pain, shortness of breath, dizziness beforehand. However, it often develops suddenly without any warning, especially during a heart attack. Therefore, if you have risk factors, you should seek emergency help without delay if you feel chest pain or sudden palpitations.

What causes ventricular fibrillation?

Ventricular fibrillation usually results from an underlying serious heart problem that causes the heart muscle to be deprived of oxygen. The most common cause is a previous heart attack or coronary artery disease. Other causes include cardiomyopathy, heart failure, electric shock, and some genetic heart diseases.

The main conditions leading to ventricular fibrillation are as follows:

• Blockage of vessels feeding the heart and damage to the heart muscle is the most common trigger for VFib. Damaged tissue formed during a heart attack can be the source of abnormal electrical signals.
• Cardiomyopathy is a primary disease of the heart muscle and increases VFib risk by reducing your heart’s contraction power. Hypertrophic cardiomyopathy is an important cause of unexplained sudden deaths in young people. Dilated cardiomyopathy can trigger ventricular fibrillation by causing heart failure.
• In heart failure, the heart’s pumping function weakens. This weakening can prepare the ground for arrhythmias by causing structural changes in the ventricles.
• Scar tissue formed after heart operations can create abnormal electrical pathways. It is an important cause of VFib.
• Congenital heart diseases, for example, some genetic diseases such as Long QT syndrome can trigger VFib.
• Electric shock can also trigger VFib. High-voltage electric current passing through the body can cause VFib by disrupting your heart’s electrical system.
• Taking some medications in excessive doses can trigger VFib.

How is ventricular fibrillation diagnosed?

Since ventricular fibrillation is a sudden condition, its diagnosis is usually made during the event, in the emergency room, or in the hospital. The most important tool for diagnosis is electrocardiography (ECG). ECG records your heart’s electrical activity and clearly shows the chaotic and irregular signals specific to VFib.

How is ventricular fibrillation treated?

Ventricular fibrillation is a condition requiring emergency medical intervention, and the main goal in treatment is to immediately return your heart to normal rhythm. This is done with a procedure called defibrillation. In long-term treatment, medications and devices such as ICD are used to prevent possible new attacks.

The methods applied in ventricular fibrillation treatment are as follows:

Emergency defibrillation

The first and most important treatment in VF is giving electrical shock to the heart through two electrodes placed on your chest. This shock aims to stop your heart’s chaotic electrical activity and return it to normal rhythm. Every second is important.

Cardiopulmonary resuscitation (CPR)

CPR application, which includes chest compression and artificial respiration until the defibrillator arrives, partially provides blood flow to vital organs and increases the chance of survival.

Drug therapy

Anti-arrhythmic drugs can be used to regulate your heart’s rhythm and prevent new VF attacks.

Implantable cardioverter-defibrillator (ICD)

This small device attached to the chest or under the collarbone of patients at high risk of sudden death continuously monitors your heart’s rhythm. When the device detects VFib or another dangerous arrhythmia, it automatically gives electrical shock to return heart rhythm to normal. This is a life-saving prevention tool.

What are the risks and complications of ventricular fibrillation?

Ventricular fibrillation is the most dangerous arrhythmia that does not resolve spontaneously and requires emergency intervention. When not treated, its most important and feared complication is sudden cardiac arrest and death.

How can ventricular fibrillation be prevented?

The best way to prevent ventricular fibrillation is to manage underlying heart diseases and control risk factors. This both stops the progression of the disease and reduces the risk of dangerous arrhythmias such as VFib.

What you can do to prevent ventricular fibrillation:

• If you have diseases such as heart attack, heart failure, or cardiomyopathy, go to regular doctor check-ups and use your medications regularly.
• Regular exercise, balanced nutrition, maintaining your ideal weight, and avoiding stress strengthen your general heart health.
• Smoking is one of the most important factors that greatly increases the risk of heart attack and heart disease.
• For patients at high risk of sudden death, using an implantable cardioverter-defibrillator (ICD) is the most effective method in preventing VFib.

When should you consult a doctor?

VFib is usually a condition that occurs suddenly without giving prior symptoms and requires emergency intervention. However, if you have previously been diagnosed with heart disease or are experiencing symptoms such as chest pain, palpitations, shortness of breath, dizziness, or fainting, you should consult a doctor without delay.

If you have previously been diagnosed with arrhythmias such as ventricular tachycardia and your symptoms are worsening, you need to be checked.

If you are a patient with an ICD and you feel your device giving consecutive shocks, doctor control is required.

Reference: Ventricular Fibrillation (VFib)