Sudden cardiac arrest (SCA) is one of the leading causes of death in the U.S., claiming the lives of nearly 300,000 people every year.

But what do you really know about this killer that often strikes without warning?

Here are the facts:

SCA is not a heart attack

While heart attacks and SCA do have some things in common, they are not the same.

A heart attack is when an artery or arteries in the heart are blocked, which prevents the heart from getting the blood that it needs. This causes damage to the heart that could lead to SCA.

SCA itself, however, is a different problem. It’s when the electrical system that keeps the heart pumping stops working, causing the heart to beat rapidly and irregularly. This can often be triggered by a heart attack, but they are two distinct events.

SCA can strike anyone at any time

There is a common misconception that only people who are overweight or generally unhealthy can suffer from SCA. In fact, it can strike anyone at any time without prior warning.

While no one is immune to SCA, there are certain factors that can increase a person’s risk:

- Obesity

- Drug use

- Other heart conditions or previous SCA

- Family history of SCA or other heart problems

- Diabetes

- Smoking

Using an AED immediately can save lives

If someone suffers from SCA, an AED applied within the first minute can raise the survival rate to 90%, up from 5% without any AED at all or if defibrillation is delayed by more than 10 minutes. 30-50% of SCA deaths could have been prevented with an AED.

In the event of SCA, it is absolutely critical that an AED be applied as soon as possible. For every minute that passes without defibrillation, the survival rate decreases by 7-10%.

While AED training is always a good thing, it is not a requirement for using an AED. Most AEDs will walk you through the process, and will not administer a shock if the victim doesn’t need one.

Know where AEDs are, and if an emergency arises, do your best to keep your composure and use one.