Imagine that you’re out to dinner with a few friends. Suddenly, a few tables over, a person clutches their chest and falls from their chair, collapsing to the ground. A few people rush to their aid while another calls for an ambulance. When people retell the story, many people will say the person suffered a heart attack. A few might say they suffered cardiac arrest.
The terms “heart attack” and “cardiac arrest” are often used interchangeably. In reality, they are distinct, typically with different causes and requiring different responses in the moment to get the person the help they need. Here are a few key points about the difference between a heart attack and cardiac arrest, along with how to recognize each and what to do if you or someone close to you suffers one.
A heart attack occurs when there is blockage of an artery (blood vessel) that supplies blood to the heart tissue. This causes a lack of oxygen supply, death of heart cells, and symptoms like chest pain, but the heart usually keeps beating. By contrast, cardiac arrest means that the heart stops beating. In some cases, a heart attack causes cardiac arrest, but there are also many other causes of cardiac arrest.
Cardiac arrest describes a condition when the heart stops pumping blood and oxygen to the brain and other organs and tissues. It can be caused by anything that makes the heart stop beating, including some severe heart attacks.
A heart attack can cause cardiac arrest, but not all cardiac arrests are caused by heart attacks.
While heart attacks can cause cardiac arrest, most do not. The blockage that causes a heart attack can be sudden, but the narrowing of arteries in the heart leading to the blockage typically occurs over a more extended period of time. High blood pressure, diabetes, sedentary lifestyle and diet choices increase the risk of narrowing the blood vessels (called atherosclerosis). As the narrowing becomes more severe, this limited blood flow causes chest pain when people exert themselves. A person may be able to go about their daily life without any pain or discomfort, but when they exert themselves, they may experience chest pain caused by that restricted blood flow. Typically, once the exertion is stopped, the pain resolves. This is what we call angina. It is a sign of blockages but doesn’t typically involve having active damage to the heart muscle. These symptoms are often progressive. Over time, it will take less and less physical exertion to experience the same pain and symptoms. It is important for patients to discuss these symptoms with their primary care doctor, who may recommend a stress test or refer them to a cardiologist.
If the pain does not go away, it could be a sign of a heart attack, and one should call for an ambulance immediately.
Heart attacks may have other symptoms too that aren’t just chest pain. Some patients describe the symptoms as pressure; others will say pain, throbbing, or stabbing. It is most commonly felt on the left side of the chest but can also feel like the pain is going into the neck and the left arm. Sometimes people will describe tingling or pain in the arm, and other times it will be throat or jaw pain. They may also sometimes experience trouble breathing. Other signs and symptoms might include nausea and feeling sweaty. Women often do not have these textbook symptoms and may only experience a change in energy or general discomfort.
Anyone who experiences these symptoms that don’t go away with rest should call for an ambulance to go to an emergency department to be evaluated because they may be having a heart attack.
Cardiac arrest occurs when the heart is not beating enough to pump blood to the brain and other tissues. One common cause, especially in adults, is an abnormal heart rhythm. Another possible cause is stopping breathing, such as when a person chokes on something or drowns. Cardiac arrest could also happen if a person cannot breathe well enough because of a severe lung infection or severe asthma attack that is left untreated. A very large blood clot in the lung can also cause cardiac arrest. It is frequently difficult to determine the cause of cardiac arrest when it occurs. The most important thing a bystander can do if they see a person who they think is in cardiac arrest is to call 9-1-1 and start CPR.
One thing heart attacks and cardiac arrest episodes have in common: they are both life-threatening events that require immediate medical attention.
A heart attack is a lot like a stroke — the faster medical professionals can open up the blockage, the less permanent damage is done to the heart muscle. Individuals suffering from a heart attack should always call 9-1-1 and have an ambulance take them to the hospital rather than driving themselves. This ensures they have the medical attention they need during the ride, and in some cases, they can be taken to a different hospital to get more optimal care, even if it is farther away.
For cardiac arrest, it’s essential to ensure that medical help is on the way as soon as possible. CPR should be started immediately by one rescuer while another contacts emergency services and retrieves an automated external defibrillator (AED) if available. CPR should not be delayed while the AED is retrieved, and the AED may be used as soon as it is available. Some emergency services dispatchers provide telephone instructions to help direct care, including instructing how to do compression-only CPR. Using the AED has been proven to save lives if the cause of the cardiac arrest is a certain type of irregular heart rhythm.
For more on the differences between a heart attack and cardiac arrest, visit the Manuals page on cardiac arrest and the Manuals page on coronary artery disease or the Quick Facts on heart attacks.