Heart Attack vs. Cardiac Arrest: Knowing the Difference Can Be Lifesaving

Imagine you're in a crowded room, and suddenly, someone clutches their chest before collapsing to the ground. Is it a heart attack, or could it be a cardiac arrest? While both are heart-related emergencies, they differ significantly in their causes, symptoms and treatments. Knowing the difference in that critical moment could be the key to saving a life.

What Is a Heart Attack?

According to the American Heart Association, someone in the U.S. experiences a heart attack approximately every 40 seconds. A heart attack, or myocardial infarction, occurs when a blockage in one or more coronary arteries—the vessels that supply oxygen-rich blood to the heart muscle—reduces or completely cuts off the flow of blood. This blockage is typically the result of coronary artery disease, where plaque made of fat, cholesterol and other substances builds up inside the arteries. When this plaque ruptures, it can cause a blood clot to form at the site, blocking the artery and preventing oxygen from reaching the heart muscle.

Without adequate oxygen, the heart muscle begins to die, making immediate treatment crucial for limiting damage and saving a life.

Common symptoms of a heart attack, according to the American Heart Association, include:

• Chest pain or discomfort: Often described as a squeezing, pressure or feeling of fullness in the chest that can last for more than a few minutes or may come and go
• Pain in other areas: Discomfort may spread to the arms (especially the left arm), neck, jaw, back or stomach
• Shortness of breath: Can occur with or without chest pain and may be mistaken for a respiratory issue

Although chest pain is the most common heart attack symptom for both men and women, women may experience symptoms differently, according to the American Heart Association:

• Unusual fatigue: Often extreme and out of proportion to normal activity
• Dizziness or lightheadedness: Can occur even without chest pain
• Nausea or vomiting: Can be confused with indigestion or a stomach bug

It’s important to understand that heart attacks don’t always follow the dramatic, sudden onset many people imagine. Some develop gradually, with mild symptoms over hours or even days, such as chest discomfort, shortness of breath or fatigue, which can often be mistaken for less serious conditions. Other heart attacks are sudden and severe, with intense chest pain, sweating and dizziness. There also are silent heart attacks, where symptoms are so subtle they may go unnoticed or mistaken for indigestion, flu-like symptoms or muscle strain. These silent heart attacks are dangerous because they can go untreated, so it’s vital to pay attention to any unusual sensations in your body.

What Is Cardiac Arrest?

Cardiac arrest, or sudden cardiac arrest (SCA), is not caused by a blockage in blood flow but by an electrical malfunction in the heart, according to the National Institutes of Health. Normally, the heart’s electrical system ensures a steady rhythm, allowing the heart to pump blood efficiently. During cardiac arrest, however, this system breaks down, leading to a dangerously erratic heart rhythm known as ventricular fibrillation (VF). Instead of pumping blood, the heart’s lower chambers (ventricles) begin to quiver uncontrollably, preventing blood from circulating throughout the body.

Without a steady heartbeat, the heart stops pumping blood to vital organs, such as the brain and lungs. Without immediate action—such as CPR or a shock from an automated external defibrillator (AED)—the lack of oxygen can lead to unconsciousness, brain damage or death within minutes.

Common signs of cardiac arrest, according to the National Institutes of Health, include:

• Sudden collapse: May collapse without warning and become unresponsive
• No pulse: Heart stops functioning, and no detectable pulse
• Gasping or not breathing: Taking abnormal, gasping breaths or not breathing

Because cardiac arrest happens without warning and progresses quickly, time is critical. According to the Sudden Cardiac Arrest Foundation, for every minute that passes without intervention, the chances of survival decrease by seven to 10 percent.

Causes of Heart Attack and Cardiac Arrest

Although heart attacks and cardiac arrests are different, a heart attack can sometimes lead to cardiac arrest. For example, during a heart attack, if the heart muscle is damaged enough to disrupt the electrical system, it can trigger sudden cardiac arrest. However, cardiac arrest does not cause a heart attack.

Causes of Heart Attack:

• Coronary artery disease: The most common cause due to plaque buildup in arteries
• Blood clots: Plaque ruptures can trigger clots that block the artery
• Coronary artery spasm: A rare cause where the artery temporarily tightens, restricting blood flow

Causes of Cardiac Arrest Include:

• Arrhythmias: Ventricular fibrillation and ventricular tachycardia (abnormally fast rhythms) are leading causes
• Heart disease: Heart failure, primary diseases of the heart muscle (cardiomyopathy) or coronary artery disease
• Genetic factors: Long QT Syndrome and other electrical abnormalities
• Trauma or external factors: Drug overdoses, electric shocks or severe trauma

Shared Risk Factors

Several common risk factors can increase the likelihood of experiencing either a heart attack or cardiac arrest:

• Age: Particularly, men over 55 and women over 65
• Smoking
• High blood pressure: Can damage the arteries over time, leading to heart attacks and increasing the risk of arrhythmias
• High cholesterol: Contributes to plaque buildup
• Diabetes
• Obesity: Strains the heart, increases cholesterol levels and raises blood pressure

How to Respond in an Emergency

For a Heart Attack:

If you suspect someone is having a heart attack, act fast. Call emergency services immediately—don’t delay more than five minutes after symptoms start. Unlike cardiac arrest, where CPR or an AED may be necessary, someone having a heart attack is usually conscious, and their heart is still beating. Encourage them to sit, rest and stay calm while waiting for help. If they are not allergic to aspirin, chewing an aspirin tablet can help slow blood clot formation.

Avoid driving the person to the hospital yourself—EMS professionals can begin life-saving treatment on the way. The only rare exception might be if you’re very close to a hospital and expect a significant delay in the arrival of an ambulance. If you’re the one experiencing heart attack symptoms, never attempt to drive yourself. Don't hesitate to call 911 out of fear of embarrassment or feeling like you're bothering anyone—it’s always better to be safe than sorry. The sooner professional medical treatment is provided, the better the outcome.

For Cardiac Arrest:

If someone suddenly collapses and is unresponsive, it's crucial to act immediately. First, call 911 immediately and tell the dispatcher about the situation. They can guide you through performing hands-only CPR, which is simple and effective. Hands-only CPR involves pushing hard and fast in the center of the person’s chest, about 100 to 120 compressions per minute until help arrives. Even without formal CPR training, this action can help keep blood flowing to vital organs.

If there’s an AED available, don’t worry if you’ve never used one before. AEDs are designed to be user-friendly and provide verbal instructions as soon as you turn them on. The machine will analyze the heart’s rhythm and instruct you whether or not a shock is needed. Simply follow the AED's prompts, and it will guide you through every step.

In an emergency, any effort is better than doing nothing. Even without formal training, your quick actions can make a life-saving difference.

Preparation and Prevention to Protect the Heart

Taking proactive steps to protect your heart and learning how to respond to a crisis not only reduces your risk but also could save lives.

• Learn CPR: CPR can save lives, particularly in cardiac arrest cases where every second counts. Many organizations, such as the American Heart Association, offer in-person and online classes, making it easy to learn this critical skill.
• Familiarize yourself with AEDs: Many public places have AEDs. Knowing how to use them is crucial in an emergency. Most AEDs come with verbal instructions, but a brief American Red Cross AED training course can give you the knowledge to act quickly and effectively.
• Maintain a heart-healthy lifestyle: Prevention is always the best approach to heart health. You can lower your risk of heart disease by embracing lifestyle habits that support your heart:
  • Exercise regularly: Aim for at least 150 minutes of moderate or 75 minutes of vigorous activity each week. Activities such as brisk walking, swimming or cycling help keep your heart strong.
  • Eat a balanced diet: Focus on a diet rich in fruits, vegetables, whole grains, lean proteins and healthy fats such as those found in nuts and fish. Limiting processed foods and excessive salt and sugar intake can protect your heart.
  • Avoid smoking and limit alcohol consumption: Smoking is one of the leading causes of heart disease, and cutting back on alcohol can reduce stress on your heart.
  • Manage stress: Chronic stress can contribute to high blood pressure and heart issues, so practicing mindfulness, deep breathing or yoga can benefit your heart and overall well-being.
  • Get regular checkups: Seeing your healthcare provider regularly allows them to monitor key indicators of heart health, such as blood pressure, cholesterol and blood sugar levels. Early detection of heart disease can lead to lifestyle changes or treatments that help prevent some heart conditions.

By knowing the difference between a heart attack and cardiac arrest, responding quickly and appropriately and taking proactive steps to protect your heart health, you're not only just safeguarding your own life but also equipping yourself to help others. Every second matters, and with the proper knowledge, you can be the person who makes all the difference when it counts the most.