Healthy Lifestyle

What you need to know about sudden cardiac arrest

A woman stretching down to touch her toes, presumably before going for a run

By Sankar Varanasi, MD


The American Heart Association's latest report, "Heart Disease and Stroke Statistics — 2023 Update," says that more than 356,000 people have a heart issue called cardiac arrest each year in the U.S. when they're not in a hospital. Almost 90% of these cases are deadly.

So, let's understand what it is, what signs to watch for and how we can help.

Are a heart attack and sudden cardiac arrest the same?

You might wonder, are a heart attack and sudden cardiac arrest the same thing? Even though people often use these terms like they mean the same thing, they're actually different.

A heart attack happens when a blockage stops blood from reaching part of your heart. Heart attacks can start suddenly and severely, but usually, the signs come on slowly and can last for days or even weeks.

On the other hand, sudden cardiac arrest is when your heart's electrical system goes wrong, and your heart suddenly stops beating. This stops blood from flowing to your brain and other important parts of your body. So, a heart attack is a problem with blood flow, while sudden cardiac arrest is an electrical problem.

Though they're different, they can be connected. Sudden cardiac arrest can happen during a heart attack or when recovering from one. Plus, having a heart attack makes it more likely you'll have sudden cardiac arrest. Other heart problems like cardiomyopathy (a problem with heart muscle) and arrhythmias (irregular heartbeats) can also lead to sudden cardiac arrest.

Does sudden cardiac arrest give any warning?

Even though it can seem to happen out of nowhere, there are a few signs you might notice:

  • Feeling tired or weak
  • Having trouble catching your breath
  • Fainting
  • Feeling dizzy or lightheaded
  • Feeling your heart flutter or beat too fast
  • Chest pain

What can you do if you think someone is having sudden cardiac arrest?

Research says 90% of people who have sudden cardiac arrest don't survive, but quick action can sometimes save lives. If you think someone is having sudden cardiac arrest because they aren't responding and their breathing is strange or stopped, call 911. While you're waiting for help to arrive, start doing CPR. Push hard in the middle of their chest, aiming for 100 to 120 pushes every minute. Keep going until they start breathing again or until help arrives.

If there's an automated external defibrillator (AED) around, use it right away. People with sudden cardiac arrest need an AED within 4 to 6 minutes to have a chance of surviving.

If CPR and an AED are used quickly, the survival rate for sudden cardiac arrest could triple. That's why it's so important for places to have AEDs and for ordinary people to learn how to do CPR.

Where can I get CPR/AED training?

Nuvance Health offers CPR/AED training. To learn more, visit:

For more information on cardiovascular care at Nuvance Health and The Heart Center, visit:

Dr. Sankar Varanasi is a cardiologist-electrophysiologist with The Heart Center, a division of Hudson Valley Cardiovascular Practice, P.C., now part of Nuvance Health.