The Difference Between a Heart Attack & Cardiac Arrest

Instructor: Ian Lord

Ian has an MBA and is a real estate investor, former health professions educator, and Air Force veteran.

The difference between a heart attack and cardiac arrest can be confusing, but knowing is critical in delivering the right treatment. In this lesson we will review the definitions of these two problems as well as the right bystander actions.

Heart Attack or Cardiac Arrest?

As an emergency room nurse, Candace often has to explain to family why the patient wound up in there. One of the most common points of confusion when someone has a medical emergency involving the heart is confusion of the difference between a heart attack and cardiac arrest.

Let's go over the information that Candace uses to quickly and easily instruct non-medical people what the differences are, how they are related, and how the difference changes the immediate response actions a bystander should take.

Heart Attack

The heart is a muscle which pumps oxygenated blood throughout the body. In a heart attack (or myocardial infarction) a blockage has occurred which prevents blood from flowing through a section of the heart. The nature of the problem is a physical obstruction. The arteries can narrow because of cholesterol buildup, or spasms of the artery, often caused by tobacco or illegal drugs such as cocaine, also cause blood flow obstruction. If a part of the heart does not receive oxygen-filled blood, heart tissue will begin to die.

Cardiac Arrest

Cardiac arrest is a problem with the electrical signals that cause the heart to beat. The heartbeat provides the pumping action to circulate blood in the body. Unlike in a heart attack where the heart still beats, in cardiac arrest cases the heart will stop beating. You can remember this by the word 'arrest', which means to stop.

This quickly leads to unconsciousness and death without immediate medical care. The electrical interruption of the heartbeat causes an arrhythmia, or irregular heartbeat. The disruption of the heart's normal beating means that blood fails to reach vital organs.

Bystander Response

Candace makes a point of telling patients and family that when in any doubt it is best to call 9-1-1 and seek immediate help. The longer a heart attack lasts, the greater the damage to the heart. A heart attack doesn't always lead to cardiac arrest but if a patient goes into cardiac arrest, a heart attack is often the cause.

Calling 9-1-1 will result in an ambulance dispatch that will get the patient to the hospital to begin treatment up to an hour faster than going in any vehicle other than an ambulance. The EMT's and paramedics on board are qualified to intervene if a heart attack patient goes into cardiac arrest.

They will have access to an automated external defibrillator (AED) which may restore the abnormal cardiac rhythm by shocking the patient. You've probably seen this done in movies and shows. It's where two pads are placed on the victim chest, the EMT says 'clear!' and then you see the body lift and fall.

Because cardiac arrest is a problem of electrical signals to the heat telling it to beat, electrical currents delivered externally can sometimes reset things. An AED will not help in a heart attack, as beating is not the problem in that case. The machine is programmed to only shock a patient when it is medically required.

Sometimes you might see standby AEDs in public facilities.

If a bystander sees someone go into cardiac arrest, they should begin immediate hands-only (no need for mouth to mouth) cardio pulmonary resuscitation (CPR). Compress the chest using both hands at a cadence of about 120 beats per minute; the American Heart Association suggests using the Beegee's song 'Stayin' Alive' as a tune to maintain that beat (though numerous other popular songs share this beat). Movies and TV often poorly demonstrate CPR techniques, it's a good idea to get some (often free) training.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account