Sudden cardiac arrest (SCA)

Sudden cardiac arrest (SCA) is usually caused by an electrical malfunction of the heart called ventricular fibrillation.

Ventricular fibrillation causes a quivering of the heart muscle that makes it unable to pump blood through the body. Once the blood stops circulating, a person quickly loses consciousness and the ability to breathe, and will die without effective treatment.

More people die of sudden cardiac arrest than lung cancer, breast cancer and AIDS combined.

What is the treatment for sudden cardiac arrest?

Early "hands only" or "compression only" Cardio Pulmonary Resuscitation (CPR) delivers oxygenated blood to the brain and heart muscle.

Treatment for ventricular fibrillation is an electrical shock known as defibrillation. The electrical shock can interrupt the chaotic heart rhythm and allow the heart to return to normal.

Defibrillation is most effective if it is applied within 3-5 minutes into sudden cardiac arrest. With each passing minute, the likelihood of recovery drops by 10 percent. Early use of an Automated External Defibrillator (AED) combined with CPR will increase the chance of survival for a Sudden Cardiac Arrest victim.

How common is sudden cardiac arrest?

Sudden cardiac arrest (SCA) can happen to anyone, anywhere, any time. Every day in the United States, it strikes about 1,000 people. Tragically, almost all of them die, making SCA a leading causes of death. In fact, some experts commonly refer to it as sudden cardiac death.

Is sudden cardiac arrest the same as a heart attack?


Sudden cardiac arrest is usually caused by ventricular fibrillation, an electrical malfunction of the heart.

A heart attack occurs when plaque or clots block blood flow to the heart. Although the heart continues to beat, irreversible damage to the heart muscle begins within 15 to 30 minutes. The longer the blood flow is interrupted, the more extensive the damage done. Treatment for heart attack includes angioplasty - using a tiny balloon to widen blocked vessels - and 'clot-busting' drugs known as thrombolytics.

Source: American Heart Association; Darren Boser, Lance Stephenson, A Heart for the Community: Public Access Defibrillation and the HeartSave Awareness Program, Access Medical Incorporated 2003
Reviewed By: Charles Lick, MD, medical director, Allina Health Emergency Medical Services
First Published: 05/06/2004
Last Reviewed: 03/01/2019