What is a heart attack?

Dr. Jeanne Morrison, PhD
Family Practitioner

A heart attack occurs when blood flow to the heart is interrupted or reduced by blockage in the coronary artery. Without a constant blood supply, part of the heart can be injured and begin to die from not getting enough oxygen. A heart attack requires prompt treatment to prevent heart muscle from dying and scar tissue from forming.

Simply put, a heart attack is permanent damage to your heart muscle. A heart attack occurs when a blockage in one or more of your arteries prevents the blood that normally supplies oxygen and nutrients to the heart from making it to its destination. Without the oxygen and nutrients it needs, heart tissue is damaged or dies. Even if you survive a heart attack, your heart can sustain damage that puts you at greater risk for future heart attacks and limits your heart’s ability to support your former level of activity.

An extensive blockage, especially in a major blood vessel, such as the left anterior descending artery, can cause a large heart attack. Large heart attacks that are not treated early and aggressively can lead to heart failure. Certain types of heart failure have 5-year mortality rates of 50 percent or more, worse than many forms of cancer.

It is better to go to the hospital and learn that you are not having a heart attack than to stay home and have one. That’s because the consequences of an untreated heart attack are so great. If your symptoms persist for more than 15 minutes, you are at more risk that heart muscle cells will die. That's why every second counts when you have a heart attack. It is critical for you and your heart that you receive immediate medical attention.

To receive the best care, you have about 90 minutes from the onset of the heart attack for an interventional cardiologist or surgeon to restore the flow of blood to the heart before critical heart tissue dies or is damaged. Getting to a hospital that has the ability to perform a heart catheterization and angioplasty is the first, key step in obtaining the best treatment.

All it takes is an electrocardiogram (ECG or EKG)—a simple painless test—to find out if you’re having a heart attack. You can get one in the ambulance on your way to the hospital. It is a very effective way to reduce the time it takes to get you the treatment you need.

When the blood supply to the heart is cut off completely, the result is a heart attack. It can cause permanent damage to the heart muscle if blood flow is not restored as fast as possible. Typically, chest pain caused by a heart attack may be accompanied by discomfort in other areas of the upper body, indigestion, nausea, weakness and sweating. However, heart attack symptoms vary and may be mild. According to the American Heart Association, women are somewhat more likely than men to experience some of the symptoms other than chest pain, particularly shortness of breath, nausea/vomiting and back or jaw pain.

Symptoms that indicate your heart is in danger may be present for months or years before a heart attack occurs. Persistent unusual symptoms—shortness of breath, nausea, great fatigue, angina/chest pain, fainting spells and gas-like discomfort—may be red flags for heart disease. Discuss such symptoms with your healthcare professional, even if the symptoms come and go.

A heart attack occurs when the arteries are completely blocked and blood cannot get to the heart, depriving the heart of oxygen. When the heart is deprived of the oxygen it needs, its cells begin to die.

The chest pain often associated with heart attacks is how the hearts calls for help when it is dying.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.