Cardiac arrest versus heart attack: What’s the difference?

Note: If you have questions about your heart health, it’s best to talk with a trained health professional. If your health might be in immediate danger, call 911 immediately in order to get to the nearest emergency room right away.

When you hear the phrase “cardiac arrest,” what comes to mind? Maybe it was the dramatic, on-the-basketball-court episode of Bronny James, son of Lebron James.¹ James survived his ordeal. But many people who have a cardiac arrest aren’t so lucky.²

Most people think that cardiac arrest is just another name for a heart attack. But a cardiac arrest is a distinct and separate medical event.

This article explains the similarities and differences between a cardiac arrest and a heart attack. Knowing the risk is the first step to help improve heart health. Read on, and talk to a doctor about heart health during routine examinations. If someone is experiencing symptoms of a heart attack or cardiac arrest, call 911 immediately.

In this article:

What is cardiac arrest?

The heart is a pump that sends blood through the body.³ Cardiac arrest occurs when the heart abruptly stops beating.⁴ It’s as though the electricity that operates a pump shuts off suddenly, halting this process and cutting off the flow of blood.

A heart attack, on the other hand, happens when there’s a problem with the flow of blood into the heart muscles. Cardiac muscles contract and relax more than 100,000 times a day on average.⁵ In a heart attack, one or more of the vessels that supply blood to these muscles become clogged. When that happens, cardiac muscle begins to seize up and die off.⁶

What causes cardiac arrest?

The primary cause of cardiac arrest is a heart problem known as an arrhythmia.⁷ Normally, a heart beats with a steady rhythm, which is controlled by electrical signals.⁸ Arrhythmia occurs when those electrical signals are disturbed, causing a heartbeat to become irregular — beating either too fast, too slow or erratically.⁹

There are different types of arrhythmias, but the two most closely linked to cardiac arrest are:¹⁰

• Ventricular fibrillation. The most dangerous form of arrythmia, “V-fib” happens when the heart’s lower chambers (or ventricles) fail to beat normally. They may begin to shake or quiver, which prevents the heart from pumping blood efficiently.¹¹
• Ventricular tachycardia. This occurs when misfiring electrical signals cause the ventricles to beat rapidly. Often, ventricular tachycardia is brief, lasting only a few seconds and resulting in no harm. But if it persists, ventricular tachycardia can cause more serious types of arrhythmias, including ventricular fibrillation.¹²

Cardiac arrest symptoms versus heart attack symptoms

A cardiac arrest can happen out of the blue with no warning. Most people who experience cardiac arrest, however, have one or more prior warning signs that something is wrong. These symptoms may occur within an hour of a cardiac arrest, though some might begin up to a few weeks in advance.

It’s important to be aware of the warning signs of a heart attack, a common cause of cardiac arrest:¹³

• Shortness of breath (more common in women and people assigned female at birth)
• Fatigue
• Back pain
• Flu-like symptoms
• Belly pain, nausea and vomiting (more common in women and people assigned female at birth)
• Chest pain (more common in men and people assigned male at birth)
• Persistent lightheadedness or fainting, especially while exercising or sitting or lying on the back

During cardiac arrest, a person may also have heart palpitations or the feeling that their heart is racing or “skipping a beat.” (Brief heart palpitations are common, but prolonged palpitations could be a symptom of cardiac arrest.) Symptoms that someone has had cardiac arrest include the following:¹⁴

• Sudden loss of consciousness
• Difficulty or loss of breathing
• Unresponsiveness to shouting or shaking
• Lack of a pulse

How serious is cardiac arrest?

Cardiac arrest is a very serious medical condition. In the United States, more than 356,000 people experience cardiac arrest outside of a hospital each year, according to the Centers for Disease Control and Prevention, and 60% to 80% die before reaching a hospital.¹⁵ Survivors of cardiac arrest may suffer potentially devastating aftereffects, including brain injury, damaged internal organs and psychological distress.

Heart attacks are a serious threat, too, of course. Each year, more than 800,000 people in the United States suffer heart attacks, while heart disease is the leading cause of death.¹⁶ Survivors are at risk for second heart attacks, as well as strokes, kidney disease and peripheral artery disease, which disturbs blood circulation and can cause leg pain.¹⁷

This content is for informational purposes only and is not medical advice. Consult your health care provider before taking any vitamins or supplements and prior to beginning or changing any health care practices.