What is a heart attack?

A heart attack occurs when blood flow to the heart is blocked. Without blood and the oxygen it carries, part of the heart starts to die. A heart attack doesn't have to be deadly. Quick treatment can restore blood flow to the heart and save your life.

Your doctor might call a heart attack a myocardial infarction, or MI. Your doctor might also use the term acute coronary syndrome for your heart attack or unstable angina.

What is angina, and why is unstable angina a concern?

Angina (say "ANN-juh-nuh" or "ann-JY-nuh") is a type of chest pain or discomfort that occurs when there is not enough blood flow to the heart. Angina can be dangerous. So it is important to pay attention to your symptoms, know what is typical for you, learn how to control it, and know when to call for help.

Symptoms of angina include chest pain or pressure, or a strange feeling in the chest. Some people feel pain, pressure, or a strange feeling in the back, neck, jaw, or upper belly, or in one or both shoulders or arms.

There are two types of angina:

• Stable angina has a typical pattern. You can likely predict when it will happen. It happens when your heart is working harder and needs more oxygen, such as during exercise. Your symptoms go away when you rest.
• Unstable angina is unexpected, and resting or taking nitroglycerin may not help. Your doctor will probably diagnose unstable angina if you are having symptoms for the first time or if your symptoms are getting worse, lasting longer, happening more often, or happening at rest.

Unstable angina is a warning sign that a heart attack may happen soon, so it requires treatment right away. But if you have any symptoms of angina, see your doctor.

What causes a heart attack?

Heart attacks happen when blood flow to the heart is blocked. This usually occurs because fatty deposits called plaque have built up inside the coronary arteries, which supply blood to the heart. If a plaque breaks open, the body tries to fix it by forming a clot around it. The clot can block the artery , preventing the flow of blood and oxygen to the heart.

This process of plaque buildup in the coronary arteries is called coronary artery disease, or CAD. In many people, plaque begins to form in childhood and gradually builds up over a lifetime. Plaque deposits may limit blood flow to the heart and cause angina. But too often, a heart attack is the first sign of CAD.

Things like intense exercise, sudden strong emotion, or illegal drug use (such as a stimulant, like cocaine) can trigger a heart attack. But in many cases, there is no clear reason why heart attacks occur when they do.

What are the symptoms?

Symptoms of a heart attack include:

• Chest pain or pressure, or a strange feeling in the chest.
• Sweating.
• Shortness of breath.
• Nausea or vomiting.
• Pain, pressure, or a strange feeling in the back, neck, jaw, or upper belly, or in one or both shoulders or arms.
• Lightheadedness or sudden weakness.
• A fast or irregular heartbeat.

For men and women, the most common symptom is chest pain or pressure. But women are somewhat more likely than men to have other symptoms like shortness of breath, nausea, and back or jaw pain.

Here are some other ways to describe the pain from heart attack:

• Many people describe the pain as discomfort, pressure, squeezing, or heaviness in the chest.
• People often put their fist to their chest when they describe the pain.
• The pain may spread down the left shoulder and arm and to other areas , such as the back, jaw, neck, or right arm.

Unstable angina has symptoms similar to a heart attack.

What should you do if you think you are having a heart attack?

If you have symptoms of a heart attack, act fast. Quick treatment could save your life.

If your doctor has prescribed nitroglycerin for angina:

1. Take 1 dose of nitroglycerin and wait 5 minutes.
2. If your symptoms don't improve or if they get worse, call 911 or other emergency services. Describe your symptoms, and say that you could be having a heart attack.
3. Stay on the phone. The emergency operator will tell you what to do. The operator may tell you to chew 1 adult-strength or 2 to 4 low-dose aspirin. Aspirin helps keep blood from clotting, so it may help you survive a heart attack.
4. Wait for an ambulance. Do not try to drive yourself.

If you do not have nitroglycerin:

1. Call 911 or other emergency services now. Describe your symptoms, and say that you could be having a heart attack.
2. Stay on the phone. The emergency operator will tell you what to do. The operator may tell you to chew 1 adult-strength or 2 to 4 low-dose aspirin. Aspirin helps keep blood from clotting, so it may help you survive a heart attack.
3. Wait for an ambulance. Do not try to drive yourself.

The best choice is to go to the hospital in an ambulance. The paramedics can begin lifesaving treatments even before you arrive at the hospital. If you cannot reach emergency services, have someone drive you to the hospital right away. Do not drive yourself unless you have absolutely no other choice.

If you think you are having unstable angina but you are not sure, follow the steps listed above. Unstable angina can lead to a heart attack or death, so you need to have it checked right away.

How is a heart attack treated?

If you go to the hospital in an ambulance, treatment will be started right away to restore blood flow and limit damage to the heart. You may be given:

• Aspirin and other medicines to prevent blood clots.
• Medicines that break up blood clots (thrombolytics).
• Medicines to decrease the heart's workload and ease pain.

At the hospital, you will have tests, such as:

• Electrocardiogram (EKG or ECG). It can detect signs of poor blood flow, heart muscle damage, abnormal heartbeats, and other heart problems.
• Blood tests, including tests to see whether cardiac enzymes are high. Having these enzymes in the blood is usually a sign that the heart has been damaged.
• Cardiac catheterization, if the other tests show that you may be having a heart attack. This test shows which arteries are blocked and how your heart is working.

If cardiac catheterization shows that an artery is blocked, a doctor may do angioplasty right away to help blood flow through the artery. Or a doctor may do emergency bypass surgery to redirect blood around the blocked artery.

After these treatments, you will take medicines to help prevent another heart attack. Take all of your medicines correctly. Do not stop taking your medicine unless your doctor tells you to. If you stop taking your medicine, you might raise your risk of having another heart attack.

After you have had a heart attack, the chance that you will have another one is higher. Taking part in a cardiac rehab program helps lower this risk. A cardiac rehab program is designed for you and supervised by doctors and other specialists. It can help you learn how to eat a balanced diet and exercise safely.

It is common to feel worried and afraid after a heart attack. But if you are feeling very sad or hopeless, ask your doctor about treatment. Getting treatment for depression may help you recover from a heart attack.

Can you prevent a heart attack?

Heart attacks are usually the result of heart disease, so taking steps to delay or reverse coronary artery disease can help prevent a heart attack. Heart disease is the number one killer of both men and women in the United States, so these steps are important for everyone.

To improve your heart health:

• Don't smoke, and avoid secondhand smoke. Quitting smoking can quickly reduce the risk of another heart attack or death.
• Eat a heart-healthy diet that includes plenty of fish, fruits, vegetables, beans, high-fiber grains and breads, and olive oil.
• Get regular exercise. Your doctor can suggest a safe level of exercise for you.
• Control your cholesterol and blood pressure.
• Manage your diabetes.
• Lower your stress level. Stress can damage your heart.
• Take a daily aspirin if your doctor advises it.