Which cardiac dysrhythmia is life threatening and requires immediate intervention?

Overview

Ventricular fibrillation is a type of irregular heart rhythm (arrhythmia). During ventricular fibrillation, the lower heart chambers contract in a very rapid and uncoordinated manner. As a result, the heart doesn't pump blood to the rest of the body.

Ventricular fibrillation is an emergency that requires immediate medical attention. It's the most frequent cause of sudden cardiac death.

Emergency treatment for ventricular fibrillation includes cardiopulmonary resuscitation (CPR) and shocks to the heart with a device called an automated external defibrillator (AED). Medications, implanted devices or surgery may be recommended to prevent episodes of ventricular fibrillation.

Ventricular fibrillation may also be called VFib, V-fib or VF.

Symptoms

Collapse and loss of consciousness are the most common symptoms of ventricular fibrillation.

Before a ventricular fibrillation episode, you may have symptoms of an irregularly fast or erratic heartbeat (arrhythmia). You may have:

• Chest pain
• Very fast heartbeat (tachycardia)
• Dizziness
• Nausea
• Shortness of breath

When to see a doctor

Make an appointment with a heart doctor (cardiologist) if you have an unexplained fast or pounding heartbeat.

If you see someone collapse, seek emergency medical help immediately. Follow these steps:

• Call 911 or your local emergency number.
• If the person is unconscious, check for a pulse.
• If no pulse, begin CPR to help keep blood flowing through the body until an automated external defibrillator (AED) is available. The American Heart Association recommends hands-only CPR. Push hard and fast on the person's chest — about 100 to 120 times a minute. It's not necessary to check the person's airway or deliver rescue breaths. Continue until emergency medical help arrives.
• Use an AED as soon as it's available. Deliver a shock following the prompts on the device.

Causes

Ventricular fibrillation is caused by either:

• A problem in the heart's electrical properties
• A disruption of the blood supply to the heart muscle

Sometimes, the cause of ventricular fibrillation is unknown.

To understand more about how ventricular fibrillation occurs, it may be helpful to know how the heart typically beats.

The heartbeat

The typical heart has four chambers — two upper chambers (atria) and two lower chambers (ventricles). Within the upper right chamber of the heart (right atrium) is a group of cells called the sinus node. The sinus node is the heart's natural pacemaker. It produces the signals that start each heartbeat.

These electrical signals move across the atria, causing the heart muscles to squeeze (contract) and pump blood into the ventricles.

Next, the signals arrive at a cluster of cells called the AV node, where they slow down. This slight delay allows the ventricles to fill with blood. When the signals reach the ventricles, the lower heart chambers contract and pump blood to the lungs or to the rest of the body.

In a typical heart, this heart signaling process usually goes smoothly, resulting in a typical resting heart rate of 60 to 100 beats a minute. But in ventricular fibrillation, rapid, irregular electrical signals cause the lower heart chambers to quiver uselessly instead of pumping blood.

Risk factors

Things that may increase the risk of ventricular fibrillation include:

• A previous episode of ventricular fibrillation
• A previous heart attack
• A heart problem present at birth (congenital heart defect)
• Heart muscle disease (cardiomyopathy)
• Injuries that cause damage to the heart muscle, such as being struck by lightning
• Drug misuse, especially with cocaine or methamphetamine
• A severe imbalance of potassium or magnesium

Complications

Without immediate treatment, ventricular fibrillation can cause death within minutes. The condition's rapid, erratic heartbeats cause the heart to abruptly stop pumping blood to the body. Blood pressure drops suddenly and significantly. The longer the body lacks blood, the greater the risk of damage to the brain and other organs.

Ventricular fibrillation is the most frequent cause of sudden cardiac death. The risk of other long-term complications depends on how fast treatment is received.

Oct. 28, 2022

​​​​​​​​​​​​​​​Heart arrhythmia, also referred to as cardiac arrhythmia, is an abnormal rhythm of the heart.

Arrhythmias can occur when the electrical impulses that coordinate your heart rhythm do not travel normally. This causes the heart to beat too fast, too slow, or with an irregular rhythm.

Almost everyone has felt their heart "skip" or “flutter” a beat or two, and speed up in times of fear or excitement or during exercise. 

Too much caffeine and certain medications also can cause heart palpitations (heart racing or fluttering) in some people. These types of arrhythmias are generally harmless.

While most arrhythmias are harmless, some can be serious or even life threatening. When a heartbeat is too fast, too slow or irregular, the heart may not be able to pump enough blood to the body. 

Arrhythmias can be associated with serious symptoms that can affect your ability to function. Lack of blood flow can damage the brain, heart and other organs.

If irregular heartbeats are frequent or chronic, they can be very serious. Troublesome arrhythmias can be made worse, or can be caused by a weak or damaged heart. 

Uncontrolled rapid arrhythmias can result in heart weakness over time.

Types of Arr​​hythmia?

There are two major types of arrhythmia:

• Tachycardia, where the heart beat is too fast - more than 100 beats per minute
• Bradycardia, where the heartbeat is to slow – less than 60 beats per minute.

Arrhythmias are identified by where they originate in the heart and whether they cause the heart to beat slow or fast.

• Arrhythmias that start in the atria are called atrial or supraventricular (above the ventricles) arrhythmias.
• Rapid heart rhythms originating in the atria include atrial fibrillation, atrial flutter, and supraventricular tachycardia.
• Arrhythmias that start in the ventricle include ventricular tachycardia and ventricular fibrillation. These are serious, often life-threatening arrhythmias since the ventricles do most of the pumping. Ventricular fibrillation is the most common cause of sudden cardiac arrest (SCA) and is fatal if not treated within a few minutes.
• Slow heart rhythms occur when the hearts normal pacemaker fails or when there is a conduction block within the conduction pathways.

Symptoms of Arrhythmia

Arrhythmias may not cause any signs or symptoms. In fact, your doctor might find you have an arrhythmia during a routine examination. Symptoms of a heart arrhythmia include:

• A “fluttering” sensation in your chest
• A racing heartbeat (tachycardia)
• A slow heartbeat (bradycardia)
• Chest pain
• Shortness of breath
• Lightheadedness
• Dizziness
• Fainting (syncope) or near fainting
• Fatigue

Causes of Arrhythmia

Risk factors and causes of heart arrhythmias include:

• Heart disease
• Electrolyte imbalances in your blood
• Structural abnormalities of the heart
• Infection
• Abnormal electrical pathways
• Medications

When it comes to arrhythmia it’s always better to err on the side of caution. If you have a concern about an irregular heartbeat, you should contact your doctor.

Diagnosis of Arrhythmia

Arrhythmias can be hard to diagnose, especially the types that only cause symptoms every once in a while. Doctors diagnose arrhythmias based on medical and family histories, a physical exam, and the results from tests and procedures. 

These typically include blood tests, a chest X-ray, an EKG (electrocardiogram) that detects and records the heart’s electrical activity, and an echocardiogram that uses sound waves to create a moving picture of your heart. 

Sometimes it is necessary to apply a heart monitor to be worn for a specific period of time to detect intermittent arrhythmias. An invasive procedure called an electrophysiology study is sometimes performed to assess the conduction system of the heart.

Treatment Options for Heart Arrhythmia

The kind of treatment(s) you may receive depends on the severity of your condition. Possible treatments for heart arrhythmia include:

• Electrophysiology procedures (EP study, mapping, ablation)
• Cardioversion
• Implantable Cardioverter Defibrillator (ICD)
• Medical Management
• Pacemaker Implantation
• Transesophageal Echocardiogram
• Heart Surgery

Frequently Asked Questions:

Can a Heart Arrhythmia ever just go away?

Yes. People can have only one episode. This can be caused by pericarditis (membrane or sac around your heart is inflamed), alcohol or other drugs, acute illness, or electrolyte abnormalities. 

Often people who have an episode may have more in their lifetime and most are harmless.

When should I have palpitations checked out?

If you notice your heart beating out of its typical rhythm, you should talk to a doctor. This can feel as if your heart is beating with extra and/or fast heartbeats, or your heart seems to skip a beat.

Can you live a normal life with arrhythmia?

Yes. Some people may require medication or a medical procedure to control their condition. Most people are able to enjoy a normal, active lifestyle with treatment.​

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What Dysrhythmias require immediate intervention?

Which of the following cardiac dysrhythmias is life threatening?

What are the 4 types of arrhythmias?

What does acute cardiac dysrhythmia mean?