What Is the Difference Between a Heart Attack and a Cardiac Arrest — and Which Is More Dangerous?

A heart attack and a cardiac arrest are both medical emergencies. Their names might sound similar, but they’re not the same. Someone can have a heart attack without cardiac arrest, and someone else may have cardiac arrest without having a heart attack. Let’s review each condition, which symptoms to look for, and what you should do if you think someone is having a heart attack or cardiac arrest.

What is the difference between a heart attack and a cardiac arrest?

Is cardiac arrest the same as a heart attack? No, they are different conditions. 

Heart attack

A heart attack happens when your heart muscle can’t get enough blood. This can happen due to:

• A blockage in one of the arteries that supply blood to the heart muscle

• A spasm in one of the blood vessels

• Increased stress on the heart 

Symptoms of a heart attack include:

• Chest pain

• Pain in the left side of the jaw or left arm

• Shortness of breath

• Nausea

Cardiac arrest

A cardiac arrest happens when your heart suddenly stops pumping blood normally. This can happen because:

• The heart stops beating

• The heart develops an abnormal rhythm that keeps it from effectively pumping blood

Some people who have a cardiac arrest have a history of heart disease, but some don’t. Symptoms of a cardiac arrest are: 

• Loss of consciousness

• Loss of pulse

Which is more dangerous, a heart attack or a cardiac arrest?

A cardiac arrest is more dangerous than a heart attack. Without treatment, it can be fatal within minutes. Up to 80% of people who have a cardiac arrest outside of a hospital die before reaching the hospital. Even with immediate treatment, the risks for brain damage after a cardiac arrest are high.

A heart attack can sometimes result in death, but it’s less likely to cause death than a cardiac arrest. Sometimes, people who have risk factors for heart disease may have brief episodes of reduced blood flow to the heart in the days or weeks before having a heart attack. 

Unlike during a cardiac arrest, the heart usually still pumps blood around the body during a heart attack. Even when a heart attack happens suddenly, treatment within hours, rather than minutes, can still be lifesaving. 

It’s important to note that while a heart attack and a cardiac arrest are different, a heart attack may increase the risk of having a cardiac arrest.

What causes a cardiac arrest?

Cardiac arrests are often caused by heart disease, but not always. Other heart problems can increase your risk of cardiac arrest, including:

• Heart attack

• A thickened heart muscle

• Heart failure

• A history of arrhythmia (irregular heart rhythm)

Cardiac arrests can also be caused by: 

• Low blood pressure

• Electrolyte imbalances in the blood

• Low blood oxygen levels

• Low body temperature

• Blood clots in the lungs or heart

• Trauma or accidents

• Certain drugs or toxins 

How can you tell whether someone is having a heart attack or a cardiac arrest?

It can be difficult to tell whether someone is having a heart attack. One reason for this is that the symptoms of a heart attack can be different for different people. Another reason is that other conditions — like a panic attack, heartburn, or asthma attack — can sometimes cause some of the same symptoms. 

There are some symptoms that make it likely that someone is having a heart attack, especially if they have a history of heart disease, like:

• Chest pain or chest pressure

• Shortness of breath

• Pain in the jaw, neck, arms, or back

• Nausea and vomiting

• Lightheadedness

A cardiac arrest is much easier to spot. Symptoms of a cardiac arrest include loss of consciousness, difficulty breathing, and loss of pulse. 

Someone who has a cardiac arrest may: 

• Appear very pale

• Not be able to respond to voice or touch

• Have difficulty breathing

• Have a weak pulse or no pulse at all

If a person with a cardiac arrest is hooked up to a heart monitor, the heart rhythm may look abnormal or there could be no rhythm at all — just a flat line. This means that the electrical activity in the heart is abnormal or there’s no electrical activity at all.

What are the risk factors for a cardiac arrest?

The risk factors for cardiac arrest are similar to the risk factors for heart disease or a heart attack. There are major and minor risk factors, and some risk factors are related to lifestyle. Risk factors that you may be able to change are known as modifiable risk factors.

Major risk factors

The major risk factors of cardiac arrest include:

• Increasing age

• Being born male

• Family history of heart disease, heart attack, or sudden cardiac death

Modifiable risk factors

Modifiable risk factors include:

• Smoking

• High cholesterol

• High blood pressure

• Type 2 diabetes

Minor risk factors

Minor risk factors include:

• Stress level

• Alcohol use

• Poor diet and nutrition

What is the treatment for a heart attack or cardiac arrest?

Both heart attacks and cardiac arrest are emergencies that need immediate medical care. 

The treatment for a cardiac arrest is cardiopulmonary resuscitation, or CPR. CPR involves doing chest compressions to help the heart pump blood through the body and giving breaths to help deliver oxygen to the lungs. 

Another important part of treating a cardiac arrest is using an automated external defibrillator, or AED. An AED is a simple-to-use machine that can analyze the heart’s rhythm and deliver an electric shock, if necessary, to treat an abnormal rhythm.

There are many different treatments for a heart attack. Often, treatment involves a combination of medications that:

• Thin the blood

• Slow down the heart rate

• Decrease the blood pressure

• Treat pain

Depending on the type of heart attack, a procedure known as a cardiac catheterization to help improve blood flow to the heart may be necessary. Some people may only need a cardiac catheterization. Others may need an emergency heart surgery known as coronary artery bypass graft (CABG).

What can you do if you think someone may be having a heart attack or cardiac arrest?

If you think someone may be having a heart attack or cardiac arrest, it’s important to act right away. The first thing to do is to make sure the scene is safe and then to check whether the person is breathing and has a pulse. If you see that someone isn’t breathing or doesn’t have a pulse, call for help immediately and begin chest compressions. If you’re trained in CPR, ask for an AED or grab the nearest one. A lot of public places have AEDs easily available. Even if you aren’t trained in CPR, calling for help and starting chest compressions until help arrives is very important and can make a big difference. 

Starting CPR as quickly as possible is extremely important. If CPR isn’t started within minutes, cardiac arrest is much more likely to be fatal.

If someone is having a heart attack, then they may be breathing, have a pulse, and be able to respond to you. In this case, you should stay with the person and call 911, even if you aren’t sure whether the person is actually having a heart attack. It’s also important to get as much health information from the person as you can. Having the person’s medical information can help emergency responders better care for the person, especially if they aren’t able to talk when help arrives.

Is cardiac arrest fatal?

Cardiac arrest isn’t always fatal. Bystander training in CPR coupled with the availability and use of AEDs mean that more people are surviving sudden cardiac arrest. In the past, cardiac arrest was almost always fatal. Now, about 20% of people survive and leave the hospital. 

Unfortunately, about 350,000 people die from sudden cardiac arrest every year in the U.S. The key to survival is starting CPR or using an AED within minutes of the arrest.

Is cardiac arrest painful?

Loss of consciousness is usually the first and only sign of sudden cardiac arrest. Sometimes people may experience symptoms like chest pain or chest fullness within the hour before cardiac arrest. Other vague symptoms right before sudden cardiac arrest include:

• Racing heart

• Nausea

• Vomiting

• Dizziness

• Lightheadedness

Most people don’t have any symptoms before sudden cardiac arrest. But if a person receives CPR for cardiac arrest, they may have muscle and rib pain during their recovery period. 

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Written by:

Kelly Elterman, MD

Kelly Elterman, MD, is a board-certified anesthesiologist by the American Board of Anesthesiologyand has been practicing clinically since she finished her residency training in 2013. Along with her training, she has over 10 years experience in anesthesiology.

Edited by:

Karla Robinson, MD

Karla Robinson, MD, is a medical editor for GoodRx. She is a licensed, board-certified family physician with almost 20 years of experience in health through varied clinical, administrative, and educational roles.

Reviewed by:

Frank Schwalbe, MD

Frank Schwalbe, MD, is an assistant professor of anesthesiology at the Yale School of Medicine. He has practiced anesthesiology for 30 years.

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