What Is Ventricular Fibrillation?

Overview

Ventricular fibrillation (VF) is a life-threatening condition that can result in sudden cardiac arrest and even death. This abnormal heart rhythm, which occurs when the heart's ventricles start beating uncoordinatedly , can be caused by various  factors, including heart disease, electrolyte imbalances, and certain medications. Despite advances in medical technology and treatment options, VF remains a leading cause of death worldwide. The American Heart Association (AHA) estimated in 2017 that there were 356,500 cases of out-of-hospital  cardiac arrest each year.¹ 

Given that cardiac arrest accounts for over 60% of all cardiovascular deaths, it continues to be a primary cause of death globally, underscoring the need for greater awareness and preventative measures. In this article, we'll explore the causes, symptoms, and treatment options for VF, and  ways to reduce your risk of developing this potentially life-threatening condition.

The term cardiac arrhythmia is used to refer to any disturbance in the normal heart rhythm due to an increase or a decrease in the rate of electrical signals coming from the heart muscle. Arrhythmias can originate from the atria (upper heart chambers) or the ventricles (lower heart chambers). Ventricular arrhythmias are further classified into ventricular tachycardia, ventricular fibrillation, premature ventricular contractions, and ventricular flutter. The focus of this article is on ventricular fibrillation as it’s one of the most common types of arrhythmias and accounts for almost 70% of cardiac arrests.¹

Causes of ventricular fibrillation

VF is often a complication of other underlying structural heart disease, such as coronary artery disease, heart failure, and others. Developing VF has also been linked to myocardial infarctions (heart attacks), which occur when the heart muscle is not getting enough oxygen supply due to a blockage in the coronary artery restricting the blood flow. Coronary artery disease is known to develop due to high blood pressure, diabetes, high cholesterol diet, as well as smoking and physical inactivity. Therefore, all the previously mentioned causes are also risk factors for developing VF. 

Moreover, VF has been linked to other abnormalities such as atrial fibrillation, electrolyte disturbances, some congenital heart diseases, Brugada syndrome as well as alcohol use, and a family history of sudden cardiac death. 

Additionally, there is increasing recognition of a genetic predisposition to VF, with the AGNES study identifying a susceptibility locus at 21q21 as the first reported genome-wide association.² 

Certain medications have also been associated with the risk of developing VF such as some blood pressure-lowering medication, some antidepressant medication as well as some anticancer drugs.⁴

Signs and symptoms of ventricular fibrillation

VF usually presents with symptoms very similar to a myocardial infarction such as:

• Chest pain
• Shortness of breath
• Nausea 
• Vomiting
• Sudden loss of consciousness 
• Absence of pulse

Emergency medical treatment is required to restore the heartbeat or the patient dies within minutes.³

Diagnosis of ventricular fibrillation

An electrocardiogram (ECG) is usually performed on a patient presenting with the symptoms of VF to confirm the diagnosis where a specific pattern of abnormal fibrillation waves is observed as well as a heart rate of 150 - 500 beats per minute. Family history and medication history are also key information that aid in the diagnosis of VF. Further tests include:

• Serum electrolytes
• Arterial blood gas
• Complete blood cell count
• Cardiac enzymes
• Levels of drugs
• Toxicology screen

Management of ventricular fibrillation 

Treatment of an acute case of VF requires immediate cardiopulmonary resuscitation (CPR) and defibrillation in order to restore blood flow. Patients are also given epinephrine (noradrenaline) and amiodarone (an antiarrhythmic drug). Chronic management and prevention of the condition are  key to avoiding  another event of cardiac arrest and include good compliance with antiarrhythmic medications, management of underlying heart conditions, maintaining a healthy diet and physical exercise as well as avoiding smoking and alcohol. Moreover, modern devices like implantable cardioverter-defibrillators have proven useful in lowering the rates of cardiac arrests.They are automated defibrillators that are implanted in  the heart muscle and are designed to detect abnormal heart rhythms and automatically send electric signals to the heart to restore a normal heartbeat.⁵

Risk factors of ventricular fibrillation

• Coronary artery disease
• Prior heart attack
• Heart failure
• Arrhythmias
• Family history
• Drug use
• Electrolyte imbalances
• Age
• Gender

Complications of ventricular fibrillation 

• Sudden cardiac death 
• Brain damage
• Organ damage
• Recurrence of VF

Implantable cardioverter-defibrillator (ICD) complications can include:

• Infections
• Device malfunction
• Inappropriate shocks
• Post-cardiac arrest syndrome

FAQs

How can I prevent ventricular fibrillation?

As discussed before, taking your medication on time and maintaining a healthy lifestyle and diet as well as installing an ICD in some cases can reduce the rate of acute VF attacks and help you lead a normal life.

How common is ventricular fibrillation?

As mentioned in the introduction, it’s one of the most common arrhythmias and it accounts for almost 70% of cardiac arrest cases.

When should I see a doctor?

You should see a healthcare professional whenever you experience any of the symptoms listed above:

• Chest pain
• Shortness of breath
• Nausea 
• Vomiting
• Sudden loss of consciousness 
• Absence of pulse

Summary

Ventricular fibrillation (VF) is a life-threatening arrhythmia that can cause sudden cardiac arrest and death. VF occurs when the heart's ventricles start beating in an uncoordinated manner and can be caused by various factors such as heart disease, electrolyte imbalances, and certain medications. VF is often a complication of underlying structural heart disease, such as coronary artery disease and heart failure. Symptoms of VF include chest pain, shortness of breath, nausea, vomiting, sudden loss of consciousness, and absence of a pulse. Emergency medical treatment is required to restore the heartbeat, or the patient dies within minutes. An electrocardiogram (ECG) is used to confirm the diagnosis of VF, and further tests may include serum electrolytes, arterial blood gas, complete blood cell count, cardiac enzymes, levels of drugs, and a toxicology screen. Treatment of VF requires immediate cardiopulmonary resuscitation (CPR) and defibrillation to restore blood flow, and patients may also be given epinephrine and amiodarone. Chronic management and prevention of VF include good compliance with antiarrhythmic medications, managing underlying heart conditions, maintaining a healthy diet, physical exercise, and avoiding smoking and alcohol. Modern devices like implantable cardioverter-defibrillators are useful in lowering the rates of cardiac arrest. They are designed to detect abnormal heart rhythms and automatically send electric signals to the heart to restore a normal heartbeat. Risk factors for VF include coronary artery disease, prior heart attack, heart failure, arrhythmias, family history, drug use, electrolyte imbalances, age, and gender. Complications of VF include sudden cardiac death, brain damage, and organ damage.