What is Cardiac Arrest?

What is cardiac arrest?

Cardiac arrest is the abrupt loss of heart function in a person who may or may not have been diagnosed with heart disease. It can come on suddenly or in the wake of other symptoms. Cardiac arrest is often fatal if appropriate steps aren’t taken immediately.

More than 356,000 cardiac arrests occur outside a hospital in the U.S. each year.

Is a heart attack the same as cardiac arrest?

No. The term “heart attack” is often mistakenly used to describe cardiac arrest. While a heart attack may cause cardiac arrest, the two aren't the same.

Heart attacks are caused by a blockage that stops blood flow to the heart. A heart attack refers to death of heart muscle tissue due to the loss of blood supply. It's a “circulation” problem. A heart attack is quite serious and sometimes fatal.

By contrast, cardiac arrest is caused when the heart’s electrical system malfunctions. The heart stops beating properly. The heart’s pumping function is “arrested,” or stopped.

In cardiac arrest, death can result quickly if proper steps aren’t taken immediately. Cardiac arrest may be reversed if CPR is performed and a defibrillator shocks the heart and restores a normal heart rhythm within a few minutes.

Cardiac arrest may be caused by irregular heart rhythms called arrhythmias. A common arrhythmia associated with cardiac arrest is ventricular fibrillation. In ventricular fibrillation, the heart’s lower chambers suddenly start beating chaotically and don’t pump blood.

Learn more about the differences between cardiac arrest and heart attack.

Download our Cardiac Arrest vs. Heart Attack infographic.