Cardiac arrest and heart attacks: signs and symptoms

Note: If you think you’re experiencing a heart attack or cardiac arrest, call 911 or your local emergency number.

When someone hears 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. Bronny survived his ordeal, but many people who experience cardiac arrest aren’t so lucky.

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

This article explains the similarities and differences between a cardiac arrest and a heart attack. Read on and talk to a health care provider 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 a heart attack?

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

A heart attack, on the other hand, happens when there’s a problem with the flow of blood into the heart muscles. In a heart attack, one or more of the vessels that supply blood to these muscles become clogged. When that happens, cardiac muscles begin to seize, and may die off if blood flow stops for too long.

What causes cardiac arrest?

The primary cause of cardiac arrest is a heart problem known as an arrhythmia. Normally, a heart beats with a steady rhythm, which is controlled by electrical signals. Arrhythmias can occur when those electrical signals are disturbed, causing a heartbeat to become irregular — beating either too fast, too slow or erratically. Other things that can cause arrhythmia include physical changes of the heart, certain medications, an electrolyte imbalance, and excessive physical exertion.

There are many different types of arrhythmias, but two are more closely linked to cardiac arrest:

• Ventricular fibrillation (V-Fib or VF): 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.
• Ventricular tachycardia: This occurs when misfiring electrical signals cause the ventricles to beat rapidly. Ventricular tachycardia is often brief, lasting only a few seconds and resulting in no harm. But if it persists, it can cause more serious types of arrhythmias, including ventricular fibrillation.

Cardiac arrest and heart attack symptoms

Cardiac arrest can happen without warning. Most people who experience cardiac arrest, however, have one or more 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 possible warning signs of a heart attack, a common cause of cardiac arrest:

• Back pain
• Belly pain, nausea and vomiting
• Chest pain (more common in men than in women)
• Extreme fatigue
• Flu-like symptoms
• Heart palpitations, or feeling as if the heart is racing, fluttering or skipping a beat
• Repeated dizziness or fainting, especially while exercising, lying on the back or sitting
• Shortness of breath (more common in women than in men)

 Symptoms that someone has had a cardiac arrest can include the following:

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

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. About 60 to 80 percent of those die before reaching a hospital. 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 from a heart attack. Up to one in four survivors of a heart attack experience another one. 

Key takeaways

Cardiac arrest and heart attacks are both life-threatening emergencies, but they may be caused by different problems. A heart attack can occur when blood flow to the heart muscle is blocked, while cardiac arrest happens when the heart suddenly stops beating properly due to an issue like an electrical malfunction. Recognizing the warning signs and symptoms of each and seeking immediate medical care can potentially be lifesaving.