Sudden Cardiac Arrest: Do You Know the Facts?


Sudden cardiac arrest (SCA) comes on quickly. A malfunction of the heart’s electrical system causes it to unexpectedly and abruptly stop beating properly. Oftentimes it can result in an abnormal heart rhythm called ventricular fibrillation (VF) that can cause the heart to quiver and pump blood ineffectively.

Symptoms of SCA include sudden collapse, loss of consciousness, loss of pulse, gasping, and shortness or loss of breath. The only effective treatment for VF is an electrical shock administered by an automated external defibrillator (AED) and high-quality cardiopulmonary resuscitation (CPR).

SCA is often confused with a heart attack, but they are not the same. During a heart attack, blood supply to the heart muscle is severely reduced or blocked. Symptoms of a heart attack can vary, sometimes coming on suddenly and sometimes starting slowly and persisting for hours, days, or weeks.



How to Help a Victim of SCA

There are two important ways you can help:

  1. Immediately deliver high-quality CPR to restore blood flow to the brain, heart, and vital organs
  2. Provide a defibrillating shock with an AED to stop the irregular rhythm and help the heart restore a normal rhythm

High-quality CPR has a big impact on a victim's outcome.

Not every victim will need a defibrillating shock, but all victims will need high-quality CPR. It has the potential to convert a non-shockable rhythm into a shockable one and is essential to continue moving blood throughout the body to protect vital organs.

When an SCA victim has a shockable rhythm, CPR must begin immediately after the shock is delivered to support the heart as it tries to restore a normal rhythm. Without CPR, a shock alone may be ineffective.

“Broad deployment of AEDs and increased bystander CPR could prevent as many as 50,000 deaths each year in the U.S. that are caused by SCA.”1


Public access to AEDs is critical to helping save lives.

Most AEDs are user-friendly and simple enough for anyone to use in an emergency. Many include voice prompts, text prompts, and illustrations that guide rescuers through the steps of applying electrodes, providing CPR, and delivering a defibrillating shock if needed.

AEDs should be highly visible and easily accessible in all public spaces where people gather. They should never be locked away or hidden from view, causing bystanders to waste precious time when every minute matters.

Without intervention, a victim’s chance of survival decreases by 10% with each passing minute.2 When bystanders can perform CPR immediately and use an AED within minutes, it can mean the difference between life and death.

Anyone can help save a life with the tools and confidence to act.

1 Children’s Hospital of Philadelphia website, chop.edu/conditions-diseases/sudden-cardiac-arrest. Accessed 29 Dec 2022.
2 Link MS, et al. Circulation. 2010;122:S706.