Most heart attacks are caused by a blood clot that blocks one of the coronary arteries. The coronary arteries bring blood and oxygen to the heart. If the blood flow is blocked, the heart is starved of oxygen and heart cells die.
The medical term for this is myocardial infarction.
A heart attack or acute myocardial infarction (MI) occurs when one of the arteries that supplies the heart muscle becomes blocked. Blockage may be caused by spasm of the artery or by atherosclerosis with acute clot formation. The blockage results in damaged tissue and a permanent loss of contraction of this portion of the heart muscle.
A substance called plaque can build up in the walls of your coronary arteries. This plaque is made up of cholesterol and other cells.
A heart attack may occur when:
- A disruption in the plaque occurs. This triggers blood platelets and other substances to form a blood clot at the site that blocks most or all of the oxygen-carrying blood from flowing to a part of the heart muscle. This is the most common cause of heart attack.
The cause of heart attack is not always known, but there are well known risk factors.
Progressive build-up of plaque in coronary artery
Plaque may build-up in a coronary artery at the site of a tear in the lining of the vessel.
Heart attack may occur:
- When you are resting or asleep
- After a sudden increase in physical activity
- When you are active outside in cold weather
- After sudden, severe emotional or physical stress, including an illness
Risk factors may lead to the developmen...
Coronary heart disease (CHD) is a narrowing of the small blood vessels that supply blood and oxygen to the heart. CHD is also called coronary artery...Read Article Now Book Mark Article
Heart attack - Animation
You feel a tight band of pain around your chest. The pain moves from your chest to your arms, shoulder, and neck. What could your pain mean? Could it be a heart attack, could it be the big one? Heart attacks are caused by interruption of blood supply to part of the heart. If the blood flow is blocked, your heart is starved of oxygen and heart cells die. A hard substance called plaque can build up in the walls of your coronary arteries. This plaque is made up of cholesterol and other cells. A heart attack can occur as a result of plaque buildup or the rupture of one of these plaques. We're not sure why heart attacks occur when they do. You may have a heart attack when you are resting or asleep, or after a sudden increase in physical activity, when you are outside in cold weather, or after a sudden, severe emotional or physical stress, including an illness. So, how is a heart attack treated? If you go to the hospital for a suspected heart attack, a doctor or nurse will listen to your chest with a stethoscope. You will have a blood test to look for heart damage. A coronary angiography test can show your doctor how well blood is moving through your heart. If blood moves slowly, or not at all through your coronary arteries, you have either a narrowed, or blocked artery. Other tests can look at the valves and chambers of your heart and check for abnormal heart rhythms. If you've had a heart attack, doctors can do an emergency procedure called angioplasty. This surgery or procedure can open narrowed or blocked blood vessels. Usually they'll place a small, metal mesh tube, called a stent, in your artery to help keep it open. You may also receive drugs to break up the clot in your artery. Sometimes, doctors will do heart bypass surgery to get blood flowing to your heart muscle again. After you are treated in the hospital for a heart attack, you may need to take medicines to thin your blood, to protect your heart, or to improve your cholesterol levels. You may need to take these medicines for the rest of your life. Most people who have had a heart attack also need cardiac rehabilitation. This will help you slowly increase your exercise level and learn how to follow a healthy lifestyle. After you have a heart attack, your chance of another is higher. How well you do after a heart attack depends on the damage to your heart and where the damage is, and what steps you take to prevent another one. If your heart can no longer pump blood to your body as well as it used to, you may have heart failure and will need lifelong treatment. Usually a person who has had a heart attack can slowly go back to normal activities, but you will need to take steps to prevent another heart attack.
Are You At Risk For a Heart Attack?
What causes a heart attack?Correct AnswerThe correct answer is all of the above. Heart disease can lead to a heart attack when plaque builds up in the arteries that supply blood to the heart. If a blood clot forms, it can block blood flow to the heart. This causes a heart attack. Less often, a heart attack occurs due to a spasm in an artery that supplies blood to the heart.
What are risk factors for heart disease and heart attack that you can control?Correct AnswerThe correct answer is all of the above. Not smoking is the best thing you can do for your heart. You can also lower your risk by staying at a healthy weight, eating a low-fat diet, and getting regular exercise (talk to your doctor before starting to exercise). Taking your medicine for high blood pressure and diabetes also lowers your risk.
What are the risk factors you can't control?Correct AnswerThe correct answer is all of the above. Men are more at risk for heart attacks than women, but a woman's risk increases after menopause. African-Americans, Mexican-Americans, American Indians, Hawaiians, and some Asian-Americans have a higher risk for heart problems. If your parents have heart disease, you are also at risk.
Stress can add to your risk of heart disease.Correct AnswerThe correct answer is true. Some studies have found a link between stress and heart disease. How you deal with stress can also have an effect. If you overeat, drink alcohol to excess, or smoke in response to stress, your risk goes up.
Drinking red wine is a good way to lower my risk for heart disease.Correct AnswerThe correct answer is false. While some studies show that alcohol may have small heart benefits, it also increases the risk of alcoholism, high blood pressure, obesity, and breast cancer. So if you don't drink, don't start. If you do drink, limit it to no more than one drink a day for women and two drinks a day for men.
You can't miss signs of a heart attack.Correct AnswerThe correct answer is false. Not everyone has the classic sign of a heart attack: sudden, intense chest pain. Chest pain may be mild or feel more like pressure or fullness. Not everyone has the same symptoms, so you should know all the signs of a heart attack.
What are the warning signs of a heart attack?Correct AnswerThe correct answer is all of the above. While chest pain or discomfort is the most common symptom, symptoms can be less obvious, and you may not know what's going on. The more symptoms you have, the more likely you are having a heart attack.
Women have different heart attack symptoms than men.Correct AnswerThe correct answer is false. Men and women can have all the same warning signs. However, women are more likely to have shortness of breath, back or jaw pain, nausea, or feel light-headed. These symptoms may occur without chest pressure or pain.
If you think you are having a heart attack, you should:Correct AnswerThe correct answer is call 9-1-1 right away. Minutes count during a heart attack. The sooner you get help, the less damage to your heart. Aspirin can be harmful for some people, so don't take it unless told to do so by emergency or medical personnel.
You can prevent a heart attack.Correct AnswerThe correct answer is true. The American Heart Association recommends the ABCs for heart attack prevention: Avoid tobacco. Become more active. Choose good nutrition.
A heart attack is a medical emergency. If you have symptoms of a heart attack, call 911 or your local emergency number right away.
- DO NOT try to drive yourself to the hospital.
- DO NOT WAIT. You are at greatest risk for sudden death in the early hours of a heart attack.
Chest pain is the most common symptom of a heart attack.
Chest pain is discomfort or pain that you feel anywhere along the front of your body between your neck and upper abdomen.Read Article Now Book Mark Article
- You may feel the pain in only one part of your body OR
- Pain may move from your chest to your arms, shoulder, neck, teeth, jaw, belly area, or back
Heart attack symptoms
Symptoms of a possible heart attack include chest pain and pain that radiates down the shoulder and arm. Some people (older adults, people with diabetes, and women) may have little or no chest pain. Or, they may experience unusual symptoms (shortness of breath, fatigue, weakness). Women are more likely than men to have symptoms of nausea, vomiting, back or jaw pain, and shortness of breath with chest pain.
The pain can be severe or mild. It can feel like:
- A tight band around the chest
- Bad indigestion
- Something heavy sitting on your chest
- Squeezing or heavy pressure
The pain most often lasts longer than 20 minutes. Rest and a medicine to relax the blood vessels (called nitroglycerin) may not completely relieve the pain of a heart attack. Symptoms may also go away and come back.
Other symptoms of a heart attack can include:
- Lightheadedness, dizziness
- Nausea and vomiting
- Palpitations (feeling like your heart is beating too fast or irregularly)
- Shortness of breath
- Sweating, which may be very heavy
Some people (including older adults, people with diabetes, and women) may have little or no chest pain. Or, they may have atypical symptoms such as shortness of breath, fatigue, and weakness. A "silent heart attack" is a heart attack with no symptoms that can also occur.
Exams and Tests
A health care provider will perform a physical exam and listen to your chest using a stethoscope.
- The provider may hear abnormal sounds in your lungs (called crackles), a heart murmur, or other abnormal sounds.
- You may have a fast or uneven pulse.
- Your blood pressure may be normal, high, or low.
You will have an electrocardiogram (ECG) to look for heart damage. Often, certain changes on the ECG indicate you are having a heart attack, although a heart attack can also occur without ECG changes.
An electrocardiogram (ECG) is a test that records the electrical activity of the heart.Read Article Now Book Mark Article
A blood test can show if you have heart tissue damage. This test can confirm that you are having a heart attack. The test is often repeated over time.
A troponin test measures the levels of troponin T or troponin I proteins in the blood. These proteins are released when the heart muscle has been da...Read Article Now Book Mark Article
Coronary angiography may be done right away or later in the course of illness.
Coronary angiography is a procedure that uses a special dye (contrast material) and x-rays to see how blood flows through the arteries in your heart....Read Article Now Book Mark Article
- This test uses a special dye and x-rays to see how blood flows through your heart.
- It can help your doctor decide which treatments you need next.
Other tests to look at your heart that may be done while you are in the hospital:
- Echocardiography with or with stress testing
- Exercise stress test
- Nuclear stress test
- Heart CT scan or heart MRI
Heart CT scan
A computed tomography (CT) scan of the heart is an imaging method that uses x-rays to create detailed pictures of the heart and its blood vessels. Th...Read Article Now Book Mark Article
- You will be hooked up to a heart monitor, so the health care team can see how regularly your heart is beating.
- You will receive oxygen.
- An intravenous line (IV) will be placed into one of your veins. Medicines and fluids pass through this IV.
- You may get nitroglycerin and morphine to help reduce chest pain.
- You may receive aspirin, unless it would not be safe for you. In that case, you will be given another medicine that prevents blood clots.
- Dangerous abnormal heartbeats (arrhythmias) may be treated with medicine or electric shocks.
Angioplasty is a procedure to open narrowed or blocked blood vessels that supply blood to the heart.
Angioplasty is a procedure to open narrowed or blocked blood vessels that supply blood to the heart. These blood vessels are called the coronary art...Read Article Now Book Mark Article
- Angioplasty is often the first choice of treatment. It should be done within 90 minutes after you get to the hospital, and usually no later than 12 hours after a heart attack.
- A stent is a small, metal mesh tube that opens up (expands) inside a coronary artery. A stent is usually placed after or during angioplasty. It helps prevent the artery from closing up again.
You may be given drugs to break up the clot. This is called thrombolytic therapy. It is best if these drugs are given soon after the onset of symptoms, usually no later than 12 hours after it and ideally within 30 minutes of arriving to the hospital.
Small blood vessels called coronary arteries supply oxygen carrying blood to the heart muscle. A heart attack can occur if a blood clot stops the flo...Read Article Now Book Mark Article
Some people may also have heart bypass surgery to open narrowed or blocked blood vessels that supply blood to the heart. This procedure is also called coronary artery bypass grafting and/or open heart surgery.
Open heart surgery
Heart surgery is any surgery done on the heart muscle, valves, arteries, or the aorta and other large arteries connected to the heart. The term "ope...Read Article Now Book Mark Article
TREATMENT AFTER A HEART ATTACK
After several days, you will be discharged from the hospital.
Discharged from the hospital
A heart attack occurs when blood flow to a part of your heart is blocked long enough that part of the heart muscle is damaged or dies. This article ...Read Article Now Book Mark Article
You will likely need to take medicines, some for the rest of your life. Always talk to your provider before stopping or changing how you take any medicines. Stopping certain medicines can be deadly.
While under the care of your health care team, you will learn:
- How to take medicines to treat your heart problem and prevent more heart attacks
- How to eat a heart-healthy diet
- How to be active and exercise safely
- What to do when you have chest pain
- How to stop smoking
Strong emotions are common after a heart attack.
- You may feel sad
- You may feel anxious and worry about being careful about everything you do
All of these feelings are normal. They go away for most people after 2 or 3 weeks.
You may also feel tired when you leave the hospital to go home.
Most people who have had a heart attack take part in a cardiac rehabilitation program.
Many people benefit from taking part in support groups for people with heart disease.
After a heart attack, you have a higher chance of having another heart attack.
How well you do after a heart attack depends on several factors such as:
- The amount of damage to your heart muscle and heart valves
- Where that damage is located
- Your medical care after the heart attack
If your heart can no longer pump blood out to your body as well as it used to, you may develop heart failure. Abnormal heart rhythms can occur, and they can be life threatening.
Heart failure is a condition in which the heart is no longer able to pump oxygen-rich blood to the rest of the body efficiently. This causes symptom...Read Article Now Book Mark Article
Most people can slowly go back to normal activities after a heart attack. This includes sexual activity. Talk to your provider about how much activity is good for you.
Thomas S. Metkus, MD, Assistant Professor of Medicine and Surgery, Johns Hopkins University School of Medicine, Baltimore, MD. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 09/28/2021.
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Giugliano RP, Braunwald E. Non-ST elevation acute coronary syndromes. In: Zipes DP, Libby P, Bonow RO, Mann DL, Tomaselli GF, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 11th ed. Philadelphia, PA: Elsevier; 2019:chap 60.
O'Gara PT, Kushner FG, Ascheim DD, et al. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2013;61(4):485-510. PMID: 23256913 pubmed.ncbi.nlm.nih.gov/23256913/.
Scirica BM, Libby P, Morrow DA. ST-elevation myocardial infarction: pathophysiology and clinical evolution. In: Zipes DP, Libby P, Bonow RO, Mann DL, Tomaselli GF, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 11th ed. Philadelphia, PA: Elsevier; 2019:chap 58.
Tamis-Holland JE, Jneid H, Reynolds HR, et al. Contemporary diagnosis and management of patients with myocardial infarction in the absence of obstructive coronary artery disease: a scientific statement from the American Heart Association. Circulation. 2019;139(18):e891-e908. PMID: 30913893 pubmed.ncbi.nlm.nih.gov/30913893/.