The Difference Between Heart Attack and Cardiac Arrest

Do you know the difference between a heart attack and cardiac arrest? Both are medical emergencies, but they have very different causes, symptoms, and potential outcomes.

To learn more, visit the UPMC Heart and Vascular Institute or call 1-855-UPMC-HVI (876-2484).

Heart attacks are serious medical emergencies, but it’s possible to survive a heart attack and get back to a normal life. Cardiac arrest, meanwhile, can cause death within minutes without treatment, so it’s important to understand the difference and get immediate medical help in either case.

Cardiac Arrest or Heart Attack?

What is a heart attack?

A heart attack happens when blood flow to your heart muscle is blocked. If blood flow isn’t restored quickly, the heart muscle begins to die from a lack of oxygen and scar tissue forms in its place.

Most heart attacks happen because of atherosclerosis, a condition in which a hard substance called plaque builds up inside your arteries, making them narrow or totally blocked. Plaque may also break open, causing a blood clot to form on the plaque’s surface, which blocks blood flow.

Heart attack symptoms can include:

  • Pressure, squeezing, fullness, or pain in the center of the chest that lasts more than a few minutes or stops and recurs
  • Discomfort that extends to the shoulders, arms, back, abdomen, jaw, and teeth
  • Shortness of breath
  • Sweating
  • Lightheadedness or fainting

Women may experience these heart attack symptoms: 

  • Abdominal pain that may feel like heartburn or indigestion
  • Dizziness
  • Unusual fatigue
  • Clammy skin

A heart attack is a medical emergency that can be deadly without treatment. If you think you or someone else is having a heart attack, call 911 right away. Paramedics provide the fastest, safest route to the hospital and are trained to treat you on the way.

What is cardiac arrest?

Cardiac arrest happens when your heart stops beating because of a problem with its electrical system. Without a heartbeat, blood can’t circulate to your other organs, leading to death within minutes.

It is possible for a person in cardiac arrest to be brought back to life through the use of an automated external defibrillator (AED) or cardiopulmonary resuscitation (CPR), but immediate treatment is crucial.

In most cases, cardiac arrest happens because of ventricular fibrillation, or VFib, which happens when your heart’s bottom chambers beat too fast and in an irregular way. It may also happen because of a heart attack, intense physical stress, genetic disorders, or changes to your heart’s structure.

Cardiac arrest symptoms can include:

  • Sudden loss of consciousness
  • Lack of pulse

Cardiac arrest is a medical emergency that is deadly without immediate treatment. If you think someone is in cardiac arrest, call 911 immediately and start CPR. If an AED is available, use it as soon as possible.

Can a Heart Attack Cause Cardiac Arrest?

In some cases, a heart attack can lead to cardiac arrest. The scar tissue that forms as heart muscle dies may affect how your heart’s electrical system works, leading to abnormal signals. This is one of many reasons why it’s so important to get immediate treatment for a heart attack.

What Should I Do in an Emergency?

If you think someone is having a heart attack or is in cardiac arrest, call 911 right away.