May also be called: CA; sudden cardiac arrest; SCA; cardiopulmonary arrest; circulatory arrest

Cardiac arrest is a condition in which the heart suddenly stops beating.

More to Know

With each heartbeat, blood is sent throughout the body, carrying oxygen and nutrients to every cell. A natural electrical system in the heart causes it to beat in its regular rhythm, but sometimes the electrical signals flowing through the heart don't "communicate" properly with the heart muscle. This can cause the heart to start beating in an abnormal pattern called an arrhythmia. Arrhythmias can make the heart beat too fast or too slow. Some can even cause the heart to stop pumping blood to the body. When this happens, it's called cardiac (KAR-dee-ak) arrest.

During cardiac arrest, body parts — including the brain — don't get the oxygen they need, and they can become damaged very quickly. This can cause death (called sudden cardiac death) in a matter of minutes.

Signs of cardiac arrest include a sudden collapse, no pulse, no breathing, and a loss of consciousness (passing out). Right before cardiac arrest, some people may have chest pain or shortness of breath, feel dizzy, or vomit. Often, though, cardiac arrest happens with no warning.

Cardiac arrest can be caused by heart disease, a heart attack, an enlarged heart, electrical problems in the heart, electrical shock, the use of certain illegal drugs, or an injury to the heart at the wrong moment of the heart's cycle.

When cardiac arrest happens, it's a medical emergency that needs immediate treatment with cardiopulmonary resuscitation (CPR) or an AED (automated external defibrillator) that delivers an electrical shock to start the heart beating again.

Keep in Mind

Cardiac arrest can cause death very quickly, but it is possible to survive if someone gets medical care right away. Cardiac arrest can’t always be prevented. But to minimize the risk, eat a healthy diet, keep a healthy weight, don't smoke, avoid excessive alcohol consumption, and stay physically active.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.