Merck Manuals Breaks Down Differences Between Heart Attack and Cardiac Arrest

Doctor outlines key distinctions and how to respond to both conditions

RAHWAY, N.J., May 10, 2023 /PRNewswire/ -- 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. In a new editorial on MerckManuals.com, Ranya N. Sweis, MD, MS, Northwestern University Feinberg School of Medicine, spells out differences between the two, along with how to recognize each and what to do if you or someone close to you suffers one.

Heart Attacks and Cardiac Arrests are Different

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.

Most Heart Attacks are not Associated with Cardiac Arrest

While heart attacks can cause cardiac arrest, most do not, Sweis explains. The blockage that causes a heart attack can be sudden, but the narrowing of arteries in the heart leading to a 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.          

Sweis notes that 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: A Variety of Causes

Cardiac arrest occurs when the heart is not beating enough to pump blood to the brain and other tissues, Sweis explains. 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 patient cannot breathe well enough because of a severe lung infection or severe asthma attack that is left untreated.

Both are Serious Medical Emergencies

One thing heart attacks and cardiac arrest episodes have in common: they are both life-threatening events that require immediate medical attention, says Sweis.  

A heart attack is a lot like a stroke, Sweis explains. The faster medical professionals can open up the blockage, the less permanent damage is done. 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.

For cardiac arrest, Sweis says, it's essential to ensure 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. 

You can read more about heart attacks and cardiac arrest in Dr. Sweis's editorial on MerckManuals.com.

About The Merck Manuals and MSD Manuals

First published in 1899 as a small reference book for physicians and pharmacists, The Merck Manual grew in size and scope to become one of the world's most widely used comprehensive medical resources for professionals and consumers. As The Manual evolved, it continually expanded the reach and depth of its offerings to reflect the mission of providing the best medical information to a wide cross-section of users, including medical professionals and students, veterinarians and veterinary students, and consumers. In 2015, The Manuals kicked off Global Medical Knowledge 2020, a global initiative with the goal to make the best current medical information accessible by up to three billion professionals and patients around the world by 2020. The Manuals achieved that goal, and today its medical information is available in more than 241 countries and in 13 languages. It's continuing its ambitious mission through outreach, education and creating new reliable medical resources. For access to thousands of medical topics with images, videos and a constantly expanding set of resources, visit MerckManuals.com or MSDManuals.com and connect with us on social media: For Consumers in the U.S. and its territories: Twitter and Facebook. For Professionals in the U.S. and its territories: Twitter and Facebook

About Merck

At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities. For more information, visit www.merck.com and connect with us on Twitter, Facebook, Instagram, YouTube and LinkedIn.

SOURCE The Merck Manuals