What is Unstable Angina?

Unstable angina is a type of coronary artery disease. The coronary arteries bring oxygen-rich blood to your heart. Because your heart is a muscle, it needs oxygen to work well. In coronary artery disease, one or more of these arteries may be partially or even completely blocked.

The type of coronary artery disease you have usually depends on the amount of blockage in your arteries. A heart attack, called a myocardial infarction, means the heart muscle has been damaged by not getting enough blood. Stable angina usually does not damage the heart. Unstable angina is worse than stable angina and may progress to a heart attack if not treated.

Angina is caused by a lack of oxygen in the heart muscle. The symptoms of angina include pain or discomfort in the chest, arms, back, neck, or jaw. Sometimes, anginal pain may feel like a tightness or crushing sensation, or it may be a stabbing pain or seem like numbness. Some people mistake anginal pain as indigestion or gas pain.

Having either stable or unstable angina does not always mean you will have a heart attack. But, unstable angina can be serious and should be treated by a doctor.

Purpose of this Booklet

The purpose of this booklet is to describe unstable angina and how it relates to other heart conditions, answer some common questions about this condition, and describe the main types of treatments available.

This booklet is written for people who have been told they have unstable angina, have been treated before for coronary artery disease, or think they might have coronary artery disease. It is also for people with a family member or friend who has unstable angina or stable angina.

This booklet also suggests some questions to ask your doctor, as well as the best time to ask them.

How are Stable and Unstable Angina Different?

Anginal discomfort may be different for different people. Some people have anginal discomfort when they over-exert themselves (for example, when they shovel snow). Other people feel anginal pain when they get very upset or excited. Over time, they can usually tell which activities will give them discomfort. Usually, the discomfort will go away in a few minutes. This type of chest discomfort is called stable angina.

Stable angina attacks usually have a regular pattern. But in some people the pattern of angina is different-it becomes unstable.

People with unstable angina include those who:

• Have anginal discomfort when they are resting or that awakens them from sleep.

• Suddenly develop moderate or severe discomfort on exertion when they have never had angina before.

• Have a marked increase in the frequency or severity of their discomfort.

Unstable angina is more serious than stable angina because the risk of having a heart attack is greater.

What Causes Unstable Angina?

In coronary artery disease, blockages -- made up of fats, such as cholesterol, and other debris -- form on the inside walls of the coronary arteries. In patients who have stable angina, the blockages may not seriously block the flow of blood.

In unstable angina, the blockages may be large. Sometimes, the blockage cracks open. When this happens, your body tries to heal the crack in the blockage by making a blood clot around the damage. If the clot is big enough to block the artery, the clot will keep blood flow from getting through. This can cause a heart attack.

Do I Need to See a Doctor?

This may depend on whether or not your doctor has ever told you that you have coronary artery disease.

If you have chest pain like that described on page 4 in the section "Chest Pain Can Be An Emergency," you should call an ambulance and then your doctor.

What Will Happen in the Emergency Room?

At your hospital emergency room, the doctors and nurses will decide if you have unstable angina. If you do have unstable angina, they will give you medicines through a vein in your arm to stop your pain and prevent injury to your heart. These medicines will help prevent blood clots and help your heart work more easily. You probably will be given oxygen to help you breathe and get more oxygen in your blood.

The doctors and nurses will ask how you are feeling and if the medicines have stopped your discomfort. It is important to tell them how you really feel. If the medicines do not stop your discomfort, there are other things they can do to help you.

These things need to be done quickly. The doctors and nurses may not be able to explain everything as it is happening. There will be time for you to ask questions after your doctor finds out how serious your condition is.

What Tests Will I Have?

There is more than one kind of test your doctor can do to decide how badly your coronary arteries are blocked. Some of these tests are usually done while you are in the hospital. Other tests can be done in the hospital, but you do not have to stay overnight. Some tests can be done in your doctor's office.

What Can These Tests Show?

Stress testing may help your doctor decide how much of the heart could be in danger from blockages in your arteries. An angiogram shows how severe the blockages are and where they are. If you are told that you have single, two, or three-vessel disease, it means that one, two, or three of the major coronary arteries have a blockage. Your doctor may also talk about the percentage of blockage in the vessel.

The number of blocked arteries and the percentage of blockage are used to measure the severity of your coronary artery disease. Generally, the greater the number of vessels that are blocked, the higher the percentage of blockage, and the more poorly your heart pumps blood, the more severe the disease.

These tests will give your doctor a lot of information about your condition. At this point, he or she can start to give you more information about how serious your condition is and the types of treatment available.

Treatment of Unstable Angina

After your tests, you and your doctor can decide on which treatment you should have. The treatment that is best for you will depend on the results of your tests, whether or not you are still having discomfort, and your own preferences. In general you will have three choices: medical therapy, angioplasty, or bypass surgery.

Talking with Your Health Care Team

Some people think that their doctors are too busy to answer questions. Other people do not know how to ask their questions. But talking with the doctors, nurses, and other health care providers is an important part of your care.

Your questions are important, and the people taking care of you should make the time to answer your questions and listen to what you have to say. Your preferences for the type of treatment you receive are very important.

You may feel more comfortable if a family member or friend is there when you talk to your doctors, nurses, and other health care providers. This person can help to make sure that you understand what is happening, ask questions, and tell the doctor your concerns and preferences for care.

Here are some questions to ask your doctor before you decide what the best treatment might be for you.

• Am I a candidate for medical treatment, angioplasty, or bypas surgery?

• What are the chances that my arteries will become blocked again if I have angioplasty or bypass surgery? How soon might this happen?

• Will I have to change my job or retire?

• How soon can I resume my normal activities? What about resuming sexual activity?

• How much will my treatment cost?

• Do I have to go on a low-sodium or low-fat diet? If so, for how long?

• Will I have a heart attack? Will I always have chest pain?

Can Blockages Come Back?

Neither angioplasty nor bypass surgery is a cure for coronary artery disease. Blockages continue to build up on artery walls even after angioplasty or bypass surgery.

Both angioplasty and bypass surgery can be repeated if the arteries become blocked again. The only way to stop coronary artery disease is to prevent the blockages from building up.

Although doctors do not know for sure why blockages form, they do know, from studies of large numbers of patients, that some people are more likely to have blocked arteries than others.

Your doctor may recommend that you attend a cardiac rehabilitation program. These programs usually are offered by local hospitals and very often they are covered by insurance. In a rehabilitation program, nurses, exercise specialists, and doctors will help you to change behaviors that put you at higher risk. They will also teach you how to exercise safely and help you gain confidence in your ability to live with heart disease.

Living with Coronary Artery Disease

It is normal for you to worry about your health and your future. But, you should know that most people with unstable angina do not have heart attacks. Usually, angina becomes more stable within 8 weeks. In fact, people who are treated for their unstable angina can live productive lives for many years.

Coronary artery disease does not go away. Your behavior and lifestyle will affect your condition. This is why it is so important to follow the advice of your doctor and the other health care professionals who treat you.

Every year, thousands of people are told they have coronary artery disease. This may come as a shock, especially if they have never felt ill before. Often, they become anxious about their future and wonder if they will still be able to take care of their families or other responsibilities. It is normal to feel a loss of control, as if something has taken over your life.

Doctors, nurses, members of the clergy, and counselors all have experience in helping people with coronary artery disease. They can help you and your family. It is important to talk about how you feel, not just physically, but emotionally.

The best way to feel like you are in control is to learn more about coronary artery disease -- what it is and the choices you have. When you see your doctor or other health care provider, be prepared to ask questions.

How Can I Learn More About Unstable Angina?

Organizations that can provide additional information include:

• American Heart Association

• 7272 Greenville Avenue

• Dallas, TX 75231-4596

• Phone: (800) AHA-USA1

• National Heart, Lung, and Blood Institute Information Center

• P.O. Box 30105

• Bethesda, MD 20824

• Phone: (301) 251-1222

• The Mended Hearts, Inc.

• 7272 Greenville Avenue

• Dallas, TX 75231-4596

• Phone: (214) 373-6300

For Further Information

The information in this booklet was based on the Clinical Practice Guideline on Unstable Angina. The guideline was developed by a private-sector panel of experts, including physicians, surgeons, nurses, and people with unstable angina.

Support for this guideline was provided by the Agency for Health Care Policy and Research and the National Heart, Lung, and Blood Institute. Other guidelines on common health problems are available, and more are being developed.

For more information on guidelines or to receive another copy of this booklet, call toll free (800) 358-9295 or write to:

• Agency for Health Care Policy and Research

• Publications Clearinghouse

• P.O. Box 8547

• Silver Spring, MD 20907

Figures

Outer view of heart showing the coronary arteries

Cross-section of a coronary artery showing blocked and normal sections

Cross-section of an artery showing how balloon angioplasty opens a blockage

Outer view of heart showing how grafts are used to "bypass" blocked arteries

AHCPR Publication No. 94-0604.

National Library of Medicine DOCLINE Information: CAT/9423947