Content Map Terms

Cardiac Arrest

Condition Basics

What is cardiac arrest?

In cardiac arrest, the heart suddenly stops beating. This causes blood to stop pumping to the body. If the heartbeat is not restarted within minutes, the person will die. This problem is also called sudden cardiac arrest.

Cardiac arrest is different from a heart attack, which happens when part of the heart muscle dies because blood flow to it has been blocked.

What causes it?

Cardiac arrest is usually caused by a problem with the heart's electrical system. In most cases, the heart's rhythm is too fast and irregular. This problem is called ventricular fibrillation (say "ven-TRICK-yuh-ler fib-ruh-LAY-shun"). The lower chambers of the heart (ventricles) quiver very fast and can't pump blood.

But cardiac arrest often happens to people who didn't know they had a heart problem.

Cardiac arrest can run in families. People who have a family history of sudden cardiac death have a higher risk for sudden cardiac death.footnote 1

Some other health problems can increase the chance of a deadly heart rhythm. They include:

How is it treated?

Health professionals, family or friends, and even strangers may be able to help a person right away who has cardiac arrest. They can use CPR or a device called an automated external defibrillator (AED). This device can shock the heart back to a normal rhythm. AEDs are often available in airports, malls, and other public places. To save a person, the device needs to be used within minutes of cardiac arrest.

In the ambulance and hospital, the person will receive emergency care. This care keeps the heart and lungs working to prevent damage to the body due to lack of oxygen. Doctors will try to find the cause of the cardiac arrest to prevent another one.

How can you prevent cardiac arrest?

If you have a health problem that raises your risk of cardiac arrest, treatment of that problem may help lower your risk. Medicine often can control the heart rhythm.

Your doctor may recommend a device that can detect a life-threatening abnormal heartbeat and help restore a normal rhythm. This device is typically implanted and called an ICD, or implantable cardioverter-defibrillator. Or it may be worn as a vest.

Some people have catheter ablation. This procedure can fix a bad heart rhythm without surgery. A doctor puts tubes and wires into a blood vessel to destroy a very small part of the heart that causes bad rhythms.

A healthy lifestyle can help keep your heart strong and healthy. Try to:

  • Quit smoking, if you smoke. Quitting smoking can lower your risk for cardiac arrest.footnote 1
  • Eat a heart-healthy diet. Eat more fruits and vegetables and other high-fibre foods.
  • Exercise for at least 30 minutes on most, if not all, days of the week.
  • Stay at a healthy weight. Lose weight if you need to.
  • Drink alcohol only in moderation. That means no more than 3 drinks a day for men, 2 drinks a day for women.
  • Avoid using illegal drugs, such as stimulants like cocaine, ecstasy, or methamphetamine. They can affect your heart's rhythm.

If you take medicine for a heart problem, take it exactly as prescribed. Go to your doctor appointments, and call your doctor if you're having problems.



  1. Al-Khatib SM, et al. (2016). 2016 AHA/ACC Clinical performance and quality measures for prevention of sudden cardiac death: A report of the American College of Cardiology/American Heart Association task force on performance measures. Circulation Cardiovascular Quality and Outcomes, 10:e000022. DOI: 10.1161/HCQ.0000000000000022.


Current as of: September 7, 2022

Author: Healthwise Staff
Medical Review:
Rakesh K. Pai MD, FACC - Cardiology, Electrophysiology
E. Gregory Thompson MD - Internal Medicine
Martin J. Gabica MD - Family Medicine
Adam Husney MD - Family Medicine
John M. Miller MD, FACC - Cardiology, Electrophysiology