Heart attack and cardiac arrest are not the same thing

When it comes to the heart, time is of the essence
Heart attack graph image

A heart attack and cardiac arrest are not the same, but often people incorrectly assume they are and use the terms interchangeably. But it is important to know the difference between the two because the time to respond with treatment for one or the other can be critical.

“The proper term for a heart attack is ‘myocardial infarction,’ which occurs when there is blockage that decreases blood flow to the heart muscle,” said Jeffrey Hsu, MD, PhD, cardiologist at UCLA Health.

“A myocardial infarction presents itself with the classic symptom of chest pain that gets worse when you’re physically active or under stress. In most cases, it results in a deep, crushing chest pain that sometimes happens on the left side of the chest. It can also be associated with symptoms such as difficulty breathing, feeling light-headed or feeling like your heart is racing,” Dr. Hsu said.

Cardiac arrest, on the other hand, “happens when the heart stops pumping blood to the rest of the body effectively,” Dr. Hsu said. “Although the heart muscle is still moving, it is not sufficiently pushing blood from the heart to other parts of the body, most importantly the brain.”

Unlike during a myocardial infarction, someone suffering a cardiac arrest will not be coherent.

“The person will collapse,” Dr. Hsu said. “They will not be able to engage with you because they have passed out due to the brain not getting any oxygen.”

How to respond

Quick response is essential in either case.

First, call 911. If the person is having a myocardial infarction and is lucid, have them stop whatever it is they are doing and sit down so they can rest comfortably. Doing so enables the person to breathe easier, and it also lessens the heart’s immediate need for oxygen.

Ask the person if they have a history of heart disease and if they are on any medication. If so, and they have the medication or it is nearby, assist them by getting the medication for them and keeping a close eye on them until emergency responders arrive.

What if it is cardiac arrest?

Time is of the essence. Without blood flow, irreversible harm or death can come quickly.

 “If an individual goes into cardiac arrest, the first thing to do is call for help. Then check for a pulse and begin administering CPR right away,” Dr. Hsu advised.

If you don’t know CPR, call out for someone who does.  

Also, If there is an automated external defibrillator, or AED, nearby — the devices are required by law in public places such as stadiums and airports  — apply the pads on the patient and follow instructions to begin using the device. Defibrillators in public places provide verbal instructions to users.

For heart care, visit our adult cardiology team.