Cardiac Arrest What Is Cardiac Arrest?

Kneeling person performs CPR on prone person who has suffered a heart attack.

Cardiac arrest occurs when the heart suddenly and unexpectedly stops pumping. If this happens, blood stops flowing to the brain and other vital organs. Cardiac arrests are caused by certain types of arrhythmias that prevent the heart from pumping blood.

Cardiac arrest is a medical emergency. Nine out of 10 people who have a cardiac arrest outside of a hospital die — often within minutes.

A person may be having a cardiac arrest if they:

Collapse suddenly and lose consciousness (pass out)
Are not breathing or their breathing is ineffective or they are gasping for air
Do not respond to shouting or shaking
Do not have a pulse

The main cause of cardiac arrest is ventricular fibrillation or ventricular tachycardia, which are types of arrhythmias. Important risk factors include prior cardiac arrest, coronary heart disease, heart valve disease, congenital heart defects, and arrhythmias caused by faulty genes . However, half of cardiac arrests happen to people who did not know they had a heart problem.

Cardiac arrest is a common cause of death.

Cardiac arrest causes about 300,000 to 450,000 deaths in the United States each year.
Cardiac arrest causes about half of the deaths linked with heart attack and stroke.

Calling 911 and immediately treating with cardiopulmonary resuscitation (CPR) and defibrillation can save the life of a person in cardiac arrest. A defibrillator is a device that sends an electric shock to the heart to try to restore its normal rhythm. Most people who have a cardiac arrest do not receive treatment quickly enough to survive.

Automatic external defibrillators (AEDs)

Automated external defibrillators (AEDs) are a type of portable defibrillator installed in places where people gather, such as stadiums, bus and train stations, schools, and offices. Like cardiopulmonary resuscitation (CPR), AEDs offer a way for bystanders to provide treatment until first responders arrive.

When a person has a cardiac arrest, bystanders can call 9-1-1, provide CPR, and use an AED. A person has a better chance of surviving when first responders arrive quickly, so calling 9-1-1 first is very important.

Everyone has a role in recognizing the signs of cardiac arrest and taking action to save lives.

An emergency Automated External Defibrillator (AED) sign mounted to a wall. — Signs mark locations of AEDs in public places.

Know where to find AEDs. AEDs are in many public places, including offices, schools, shopping malls, grocery stores, airports, event venues, and gyms. Check to see whether your office or school has an AED.
Learn how to use an AED. AEDs are not hard to use, but training is very helpful. AED training is often provided along with CPR training. Many major health organizations offer classes. Some training is available online. Find a course near you.
Take action to increase public access to AEDs. AEDs save lives. You can suggest installing AEDs in the places people gather and work in your community and beyond. Be alert when you travel, too, as AEDs are also important on ships, trains, and aircraft, where emergency help may not be available.