The Difference Between a Heart Attack and Cardiac Arrest

Why Knowing the Difference Matters

Many people use the terms heart attack and cardiac arrest interchangeably. While both are serious medical emergencies involving the heart, they are not the same condition. Understanding the difference is important because the correct response depends on the situation. Knowing how to recognize each situation could help save a life.

What is a Heart Attack?

A heart attack, also known as myocardial infarction, occurs when blood flow to part of the heart is blocked. The heart muscle needs oxygen-rich blood to function properly. When that blood supply is reduced or completely cut off, the affected portion of the heart muscle begins to deteriorate.

The most common cause of a heart attack is coronary artery disease (CAD). CAD occurs when plaque, a buildup of fat, cholesterol, and other substances, narrows the coronary arteries. This narrowing limits blood flow to the heart. In some cases, a severe spasm of a coronary artery can also temporarily block blood flow.

During a heart attack, the heart usually continues to beat. However, the longer the blockage remains untreated, the greater the damage to the heart muscle. Symptoms can vary and may include chest pain, shortness of breath, nausea, or discomfort in the arms, back, or jaw. It is also important to note that symptoms can differ between men and women, and some people may experience only mild warning signs.

What is Cardiac Arrest?

Cardiac arrest, also called cardiopulmonary arrest, is different from a heart attack. It occurs when the heart suddenly stops beating due to an electrical malfunction. Because the heart is no longer pumping blood, oxygen cannot reach the brain or other vital organs.

More than 365,000 people experience out-of-hospital cardiac arrest in the United States each year. Approximately 60-80% of those individuals die before reaching the hospital. Signs of cardiac arrest include sudden collapse, loss of responsiveness, absence of normal breathing (or only gasping for air), and no pulse. Unlike a heart attack, cardiac arrest often happens without any warning.

Cardiac arrest can be caused by several factors, including arrhythmias (irregular heart rhythms), cardiomyopathy (thickness or enlarged heart muscle), congenital heart defects, severe emotional stress, certain medications, heavy alcohol use, or underlying artery disease. In some cases, a heart attack itself can trigger cardiac arrest.

The Critical Difference in Emergency Care

Although heart attacks and cardiac arrest are connected, they require different immediate responses.

A heart attack is primarily a circulation problem caused by a blocked artery. The heart is still beating, and the person is usually conscious. Immediate medical attention is critical, but CPR is not typically the first step unless the person loses consciousness and stops breathing.

Cardiac arrest, however, is an electrical problem. The heart stops beating entirely and the person quickly loses consciousness. Without immediate action, brain damage can begin within minutes.

Confusing the two conditions can delay lifesaving treatment. If someone collapses and is unresponsive, assuming it is “just a heart attack” could prevent bystanders from starting CPR right away. Quick recognition and action are essential.

What To Do in a Cardiac Emergency

If someone suddenly collapses and is unresponsive, call 911 immediately. Emergency responders can begin treatment as soon as they arrive.

If the person is not breathing normally and has no pulse, begin CPR right away. Performing CPR can double or even triple a person's chance of survival. Push hard and fast in the center of the chest at a rate of 100-120 compressions per minute and continue until emergency medical services arrive.

If an Automated External Defibrillator (AED) is available, use it as soon as possible. If two people are present, one person should begin CPR while the other calls 911 and retrieves the AED. Taking quick action can make the difference between life and death.

About Hands to Heart

Hands to Heart is a student-led public health initiative dedicated to expanding hands-on CPR education for high school students. By promoting awareness and confidence in emergency situations, Hands to Heart empowers students to act quickly and effectively when it matters most.

Learning the difference between a heart attack and cardiac arrest is only the first step. Knowing how to respond, and having the confidence to do so, can save lives.