Cardiac Arrest

During cardiac arrest, an electrical problem makes your heart stop pumping blood to your body. Without blood flowing, you become unconscious and don’t have a pulse. Cardiac arrest, or sudden cardiac arrest, can be fatal in minutes. This is why you should call 911 and start CPR right away. Chances of survival are better with immediate help.


Abnormal signals cause cardiac arrest, but a clog in your artery causes a heart attack.
Cardiac arrest is an electrical problem, unlike a heart attack.

What is cardiac arrest?

Cardiac arrest happens when your heart stops beating or beats so fast that it stops pumping blood. During cardiac arrest, people typically collapse and become unresponsive. Symptoms start without warning. This is why it’s also known as sudden cardiac arrest. The condition can become fatal if you don’t get immediate treatment.

If you notice the signs of cardiac arrest, call 911 immediately.


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Why do cardiac arrests happen?

With cardiac arrest, abnormal, rapid impulses abruptly override the normal electrical impulses that start your heartbeat. When your heart isn’t beating, there’s no way to get oxygen-rich blood to the rest of your body.

Cardiac arrest vs. heart attack

Here’s how cardiac arrest and heart attack are different:

  • Cardiac arrest happens when rapid, abnormal impulses override your heart’s natural rhythm. It’s an electrical issue.
  • Heart attack occurs when a clogged artery disrupts blood flow to your heart. A heart attack is a common cause of cardiac arrest.

Is cardiac arrest the same as sudden cardiac death?

With cardiac arrest, your heart stops beating, but a rescue is still possible. With immediate treatment, you can survive.


Sudden cardiac death refers to a cardiac arrest without someone saving you.

Who does cardiac arrest affect?

Sudden cardiac arrest happens in people with and without heart disease. Having a heart attack or other heart condition can significantly increase your risk.

More than 356,000 Americans each year experience cardiac arrest outside of a hospital. It typically affects adults. Only 3% of cases involve children.

Symptoms and Causes

What are the symptoms of cardiac arrest?

Fainting can mean you’re going into cardiac arrest. Symptoms of cardiac arrest include:


Are there warning signs before cardiac arrest?

Yes. Before you faint, you may have other cardiac arrest symptoms, including:

Is cardiac arrest painful?

Some people have chest pain before they become unconscious from cardiac arrest. However, you won’t feel pain once you lose consciousness.

What causes cardiac arrest?

Irregular heart rhythms (arrhythmias) are the immediate cause of cardiac arrest.

Abnormal heart rhythms that cause cardiac arrest may include:

Conditions and situations that can lead to these abnormal heart rhythms are the underlying causes of sudden cardiac arrest. These include:

What are the most common causes of sudden cardiac arrest in children?

Conditions or accidents that can make a child’s heart suddenly stop beating include:

  • Congenital heart disease.
  • Infectious diseases.
  • Respiratory conditions.
  • Severe injury (trauma).
  • Toxins (ingesting poisonous substances).

These issues lower oxygen levels or reduce the volume of blood. This prevents your heart from functioning.

Diagnosis and Tests

How do you detect cardiac arrest?

Cardiac arrest symptoms begin suddenly, leaving little time for tests. The condition can become fatal within minutes. This is why a quick diagnosis is essential.

A person’s symptoms are often the best way to diagnose cardiac arrest, especially if they:

  • Are unconscious.
  • Have no pulse.

Management and Treatment

How is cardiac arrest treated?

Emergency cardiac arrest treatment includes restarting your heart and restoring a regular rhythm. Care includes using:

  • Cardiopulmonary resuscitation (CPR): Immediate CPR is one of the most important treatments to improve cardiac arrest survival. CPR is often performed until an automatic or external defibrillator is ready. CPR uses chest compressions to replace the heart’s pumping action. It moves small amounts of blood from your heart to your brain.
  • Automatic defibrillator or external defibrillator: Once connected, this device delivers a brief electrical current (shock) to your chest. The current travels to your heart. This stops the abnormal impulses and restores the normal impulses that make it beat. It may take more than one shock for your heart to pump on its own again.

How quickly should I receive treatment for cardiac arrest?

Cardiac arrest can be fatal if it lasts longer than 8 minutes without CPR. Brain damage can happen after just 5 minutes.

Cardiac arrest treatment should start right away, even if you’re not in the hospital. If you’re in a public area, like a school, mall or sports venue, CPR and an automated external defibrillator (AED) can help.

An AED is a device that a person without medical training can use to shock someone else’s heart. The AED confirms there’s no heartbeat before delivering the shock. Ideally, one person should use the AED while another calls 911.


How can I reduce my risk?

If abnormal heart rhythms run in your family, you may want to talk with a genetic counselor. They can tell you who might be at risk or need testing for an issue that causes arrhythmia.

Testing can let you know whether you’re at risk for sudden cardiac arrest. Healthcare providers may recommend:

How can I prevent cardiac arrest?

Treatments that can prevent cardiac arrest or lower your risk of a second episode include:

Outlook / Prognosis

What can I expect if I have cardiac arrest?

Nearly nine out of 10 people who survive cardiac arrest have permanent brain damage from a lack of oxygen. This can bring changes to your daily life and abilities.

You may experience:

Survival without brain damage is far more likely with early CPR and defibrillation.

Does cardiac arrest mean death?

While most people don’t survive a cardiac arrest, survival rates are better than they were just 10 years ago. About 11% of people who have a cardiac arrest outside a hospital and get emergency treatment survive and go home from the hospital. About 26% of people who have cardiac arrest inside a hospital survive and go home.

Living With

How will life be different after surviving sudden cardiac arrest?

You may have no memory of your heart stopping. Some people wake up in the hospital days later. After returning home, it’s not uncommon for complications to occur. You may need to go back to the hospital for more treatments.

Rehabilitation after your hospital stay can help maximize your abilities. It can take months to relearn once-simple activities like walking and getting dressed. Many people return to their daily lives, but some need ongoing help.

Researchers have seen improvements in cardiac arrest survivors’ quality of life after six months.

What else can I expect?

Surviving a life-threatening condition can cause mental health challenges (post-intensive care syndrome).

You may benefit from mental health services to help you cope with:

How do I take care of myself?

Cardiac arrest is a traumatic event that most people don’t survive.

  • Be patient with yourself while you slowly get back to being able to do things you did every day.
  • Take advantage of any programs that help you get back to normal life.
  • Keep your checkup appointments with your healthcare provider.

When should I go to the ER?

If you see someone unconscious, the best thing to do is call 911. They can send help and talk you through giving CPR.

What questions should I ask my doctor?

  • Should I buy an AED to keep at home?
  • Are there any programs available to help me adjust to my new reality?
  • Is my family at risk for cardiac arrest?

A note from Cleveland Clinic

Recovery from cardiac arrest takes time and includes therapies to help maximize your abilities. Many survivors need ongoing heart care to prevent another episode of sudden cardiac arrest. Be sure to go to all of your follow-up appointments and keep taking any prescribed medicines. It may give you peace of mind if people who live with you take a CPR class in case of another cardiac arrest. Most cardiac arrests outside a hospital happen at home.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 05/18/2022.

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