Disease Topics: Myocardial Infarction

What Is a Heart Attack?


The heart requires its own constant supply of oxygen and nutrients, like any muscle in the body. Two large, branching coronary arteries deliver oxygenated blood to the heart muscle. If one of these arteries or branches becomes blocked suddenly, a portion of the heart is starved of oxygen, a condition called "cardiac ischemia."

If cardiac ischemia lasts too long, the starved heart tissue dies. This is aheart attack, otherwise known as a myocardial infarction -- literally, "death of heart muscle."

Most heart attacks occur during several hours -- so never wait to seek help if you think a heart attack is beginning. In some cases there are no symptoms at all, but most heart attacks produce some chest pain.

Other signs of a heart attack include shortness of breath, dizziness, faintness, or nausea. The pain of a severe heart attack has been likened to a giant fist enclosing and squeezing the heart. If the attack is mild, it may be mistaken for heartburn. The pain may be constant or intermittent. Also, women are less likely to experience the classic symptoms of chest pain than men are.


Angina: Early Warning Sign of a Heart Attack

Many heart attack victims are warned of trouble by episodes of angina, which is chest pain that, like a heart attack, is provoked by ischemia. The difference is mainly one of degree: With angina, blood flow is restored, pain recedes within minutes, and the heart is not permanently damaged. With a heart attack, blood flow is critically reduced or fully blocked, pain lasts longer, and heart muscle dies without prompt treatment.

About 25% of all heart attacks occur without any previous warning signs. They are sometimes associated with a phenomenon known as "silent ischemia" -- sporadic interruptions of blood flow to the heart that, for unknown reasons, are pain-free, although they may damage the heart tissue. The condition can be detected by ECG (electrocardiogram) testing. People with diabetes often have silent ischemia.

A quarter of all heart attack victims die before reaching a hospital; others suffer life-threatening complications while in the hospital. Serious complications include stroke, persistent heart arrhythmias (irregular heart beats), heart failure, formation of blood clots in the legs or heart, and aneurysm, or bulging, in a weakened heart chamber. But those who survive the initial heart attack and are free from major problems a few hours later stand a better chance of full recovery.

Angina: Early Warning Sign of a Heart Attack continued...


Recovery is always a delicate process, because any heart attack weakens the heart to some degree. But generally, a normal life can be resumed. Depending on the severity of a heart attack, a person may experience:

  • Heart failure, where the heart doesn't pump well enough to meet the body's needs
  • Arrhythmias or abnormal heart rhythms
  • Cardiac arrest or sudden cardiac death, where the heart stops beating
  • Cardiogenic shock, where the heart is so damaged from the heart attack that a person goes into shock, which may result in damage of other vital organs like the kidneys or liver
  • Death

    What Is Acute Myocardial Infarction?


    1. Acute myocardial infarction is the medical name for a heart attack. Heart attacks occur when the flow of blood to the heart becomes blocked. They can cause tissue damage and can even be life-threatening.
    2. A number of different factors may increase your risk for a heart attack, including high blood pressure, high cholesterol, and diabetes.
    3. Call 911 immediately if you believe you or someone you know may have had a heart attack. Getting prompt medical treatment will greatly improve the chances of recovery.

    Acute myocardial infarction is the medical name for a heart attack. A heart attack is a life-threatening condition that occurs when blood flow to the heart is abruptly cut off, causing tissue damage. This is usually the result of a blockage in one or more of the coronary arteries. A blockage can develop due to a buildup of plaque, a substance mostly made of fat, cholesterol, and cellular waste products.

    Call 911 right away if you think that you or someone you know may be having a heart attack.

  • While the classic symptoms of a heart attack are chest pain and shortness of breath, the symptoms can be quite varied. The most common symptoms of a heart attack include:

    • pressure or tightness in the chest
    • pain in the chest, back, jaw, and other areas of the upper body that lasts more than a few minutes or that goes away and comes back
    • shortness of breath
    • sweating
    • nausea
    • vomiting
    • anxiety
    • a cough
    • dizziness
    • a fast heart rate

    It’s important to note that not all people who have heart attacks experience the same symptoms or the same severity of symptoms. Chest pain is the most commonly reported symptom among both women and men. However, women are more likely than men to have:

    • shortness of breath
    • jaw pain
    • upper back pain
    • lightheadedness
    • nausea
    • vomiting

    In fact, some women who have had a heart attack report that their symptoms felt like the symptoms of the flu.

    Part 3 of 8: Causes

    What Causes Acute Myocardial Infarction?

    Causes Icon

    Your heart is the main organ in your cardiovascular system, which also includes different types of blood vessels. Some of the most important vessels are the coronary arteries. They take oxygen-rich blood to all of the organs in your body, including your heart. When these arteries become blocked or narrowed due to a buildup of plaque, the blood flow to your heart can decrease significantly or stop completely. This can cause a heart attack. Several factors may lead to a blockage in the coronary arteries.

    Bad Cholesterol

    Bad cholesterol, also called low-density lipoprotein (LDL), is one of the leading causes of a blockage in the arteries. Cholesterol is a colorless substance that’s found in the food you eat. Your body also makes it naturally. Not all cholesterol is bad, but LDL cholesterol can stick to the walls of your arteries and produce plaque. Plaque is a hard substance that blocks blood flow in the arteries. Blood platelets, which help the blood to clot, may stick to the plaque and build up over time.

    Saturated Fats

    Saturated fats may also contribute to the buildup of plaque in the coronary arteries. Saturated fats are found mostly in meat and dairy products, including beef, butter, and cheese. These fats may lead to an arterial blockage by increasing the amount of bad cholesterol in your blood system and reducing the amount of good cholesterol.

    Trans Fat

    Another type of fat that contributes to clogged arteries is trans fat, or hydrogenated fat. Trans fat is usually artificially produced and can be found in a variety of processed foods. Trans fat is typically listed on food labels as hydrogenated oil or partially hydrogenated oil.

  • Who Is at Risk for Acute Myocardial Infarction?

    Certain factors may increase your risk of having a heart attack.

    High Blood Pressure

    You’re at greater risk for heart attack if you have high blood pressure. Normal blood pressure is below 120/80 mm Hg (millimeters of mercury) depending on your age. As the numbers increase, so does your risk of developing heart problems. Having high blood pressure damages your arteries and accelerates the buildup of plaque.

    High Cholesterol Levels

    Having high levels of cholesterol in your blood puts you at risk for acute myocardial infarction. You may be able to lower your cholesterol by making changes to your diet or by taking certain medications called statins.

    High Triglyceride Levels

    High triglyceride levels also increase your risk for having a heart attack. Triglycerides are a type of fat that clog up your arteries. Triglycerides from the food you eat travel through your blood until they’re stored in your body, typically in your fat cells. However, some triglycerides may remain in your arteries and contribute to the buildup of plaque.

    Diabetes and High Blood Sugar Levels

    Diabetes is a condition that causes blood sugar, or glucose, levels to rise. High blood sugar levels can damage blood vessels and eventually lead tocoronary artery disease. This is a serious health condition that can trigger heart attacks in some people.


    Your chances of having a heart attack are higher if you’re very overweight. Obesity is associated with various conditions that increase the risk of heart attack, including:

    • diabetes
    • high blood pressure
    • high cholesterol levels
    • high triglyceride levels


    Smoking tobacco products increases your risk for heart attack. It may also lead to other cardiovascular conditions and diseases.


    The risk of having a heart attack increases with age. Men are at a higher risk of a heart attack after age 45, and women are at a higher risk of a heart attack after age 55.

    Family History

    You’re more likely to have a heart attack if you have a family history of early heart disease. Your risk is especially high if you have male family members who developed heart disease before age 55 or if you have female family members who developed heart disease before age 65.

    Other factors that can increase your risk for heart attack include:

    • stress
    • a lack of exercise
    • the use of certain illegal drugs, including cocaine and amphetamines
    • a history of preeclampsia, or high blood pressure during pregnancy

    Part 5 of 8: Diagnosis

    How Is Acute Myocardial Infarction Diagnosed?

    Diagnosis Icon

    To determine whether you’ve had a heart attack, your doctor will listen to your heart to check for irregularities in your heartbeat. They may measure your blood pressure as well. Your doctor will also run a number of different tests if they suspect that you’ve had a heart attack. An electrocardiogram (EKG) may be done to measure your heart’s electrical activity. Blood tests can also be used to check for proteins that are associated with heart damage, such as troponin.

    Other diagnostic tests include:

    • a stress test to see how your heart responds to certain situations, such as exercise
    • an angiogram with coronary catheterization to look for areas of blockage in your arteries
    • an echocardiogram to help identify areas of your heart that aren’t working properly
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What Can Be Expected After Treatment?

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Your chances of recovering from a heart attack depend on how much damage there is to your heart and how quickly you receive emergency care. The sooner you receive treatment, the more likely you are to survive. However, if there’s substantial damage to your heart muscle, your heart may be unable to pump an adequate amount of blood throughout your body. This can lead to heart failure. Heart damage also increases your risk of developing abnormal heart rhythms, or arrhythmias. Your risk of having another heart attack will be higher as well.

Many people who’ve had heart attacks experience anxiety and depression. It’s important to speak with your doctor about your concerns during recovery. It may also be beneficial to join a support group or to speak with a counselor about what you’re going through.

Most people are able to resume their normal activities after a heart attack. However, you’ll need to ease back into any intense physical activity. Your doctor will help you develop a specific plan for recovery. You may be required to take medications or undergo a cardiac rehabilitation program. This type of program can help you slowly regain your strength, teach you about healthy lifestyle changes, and guide you through treatment.: Prevention

How Can Acute Myocardial Infarction Be Prevented?

Prevention Icon

There are many steps you can take to prevent a heart attack, even if you’ve had one before.

One way to lower your risk is to eat a heart-healthy diet. This diet should largely consist of:

  • whole grains
  • vegetables
  • fruits
  • lean protein

You should also reduce the amount of the following in your diet:

  • sugar
  • saturated fat
  • trans fat
  • cholesterol

This is especially important for people with diabetes, high blood pressure, and high cholesterol.

Exercising several times a week will also improve your cardiovascular health. If you’ve had a heart attack recently, you should speak with your doctor before starting a new exercise plan.

It’s also important to stop smoking if you smoke. Quitting smoking will significantly lower your risk of a heart attack and improve both your heart and lung health. You should also avoid being around secondhand smoke.

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