Unstable Angina

What is unstable angina?

Unstable angina is a type of angina (chest pain) that happens when your heart muscle doesn’t get as much oxygen-rich blood as it should. This happens because of plaque blockages and, usually, a blood clot in one or more of the arteries that feed your heart (coronary arteries). Your heart muscle can’t get enough blood while a blood clot is blocking your coronary artery. This can lead to permanent heart muscle damage — a heart attack.

Maybe you’ve had chest pain before, but now it’s unpredictable and keeps getting worse. It used to happen only when you worked in the yard, but now mild physical activity brings it on. It even shows up without warning when you’re at rest, relaxing or even asleep. Your heart needs your attention now.

Without quick treatment, unstable angina puts you at a high risk of having a heart attack. Many people who have heart attacks get unstable angina, exhaustion or shortness of breath days or weeks before their heart attack happens.

Unstable angina is an emergency. You should get medical help immediately.

In rare situations, your heart can stop beating, which is fatal.

What are the symptoms of unstable angina?

Unstable angina symptoms include:

• Tight or sharp chest pain that happens without warning.
• Pain in your chest that may spread to your arm, jaw or back.
• Chest pain that happens even when you’re not exerting yourself.
• Chest pain that doesn’t stop after you rest or take medicine.
• Shortness of breath.
• Sweating.
• Anxiety.
• Dizziness.
• Nausea and vomiting.

Episodes of unstable angina can last for 15 minutes or more. Without treatment, you can have many episodes of unstable angina.

What causes unstable angina?

Coronary artery disease is the top cause of unstable angina. Atherosclerosis (cholesterol and fat collecting inside your arteries) can lead to this disease that affects the arteries that bring blood to your heart muscle. A blood clot can form in your narrowed coronary arteries, which allows even less blood to get through. This brings on the unstable angina.

Coronary artery spasms cause a rare type of unstable angina called variant or Prinzmetal angina.

What are the risk factors for unstable angina?

Stable and unstable angina are both more common in older adults, in people who have a biological family member with coronary artery disease and in people who smoke, have diabetes or have high blood pressure. But people without any of these risks can also have unstable angina and should pay attention and act if they’re having symptoms.

What are the complications of unstable angina?

Possible complications of unstable angina include:

• Heart attack.
• Heart failure.
• Stroke.
• Abnormal heart rhythms (arrhythmia).
• Cardiac arrest (rare).

How is unstable angina diagnosed?

To make an unstable angina diagnosis, your provider will take your blood pressure and give you a physical exam. They’ll also order tests.

Tests to diagnose unstable angina can include:

• Electrocardiogram (EKG).
• Stress test.
• Cardiac blood tests.
• Echocardiogram.
• Coronary angiogram.

What are the three criteria for unstable angina?

A provider making a diagnosis of unstable angina is checking for one of three criteria. These include chest pain that:

• Started within the past two months.
• Has been getting worse.
• Happens when you’re not exerting yourself.

How is unstable angina treated?

Treatment for unstable angina should happen in a hospital where you can get immediate care to prevent a heart attack.

For unstable angina treatment, a provider may give you several medicines, like:

• Nitroglycerin to help with chest pain and improve blood flow.
• Blood thinners like aspirin or clopidogrel to protect against blood clots.
• Beta-blockers to lessen your heart’s workload.
• Cholesterol-lowering medicine.
• High blood pressure medicine.
• Medicine to help regulate your heart rhythm.

What treatments are used for unstable angina?

Unstable angina treatments may include procedures that widen your coronary arteries or reroute your blood around a blockage there. These procedures are:

• Angioplasty with stent implantation.
• Heart bypass surgery.

Complications or side effects of the treatment

Although medications sometimes have side effects, your provider prescribes medicine for you because its benefits are greater than its risks. Always talk to your provider first if you have concerns about continuing a medication. Stopping your medications without asking your provider may cause a heart attack.

Complications from procedures (some of which are rare) may include:

• Bleeding.
• Infection.
• Abnormal heart rhythm.
• Heart attack.
• Stroke.
• The need for another procedure.

How long does it take to recover from this treatment?

You can usually get back to your normal activities about a week after angioplasty. But you’ll need several weeks to recover from coronary artery bypass surgery.

How can I lower my risk of unstable angina?

You have the power to change some of the things that cause heart disease and unstable angina, like:

• Managing high blood pressure, cholesterol and sugar levels.
• Not using tobacco products or recreational drugs.
• Getting frequent physical activity.
• Eating healthy foods, like mainly fruits and vegetables.
• Staying at a weight that’s healthy for you.
• Limiting how many beverages containing alcohol you drink.

What can I expect if I have unstable angina?

In treating unstable angina, a provider’s first priority is to make sure your heart can get the blood and oxygen it needs. Medicines and procedures can improve blood flow to your heart. But you’ll likely need to take medicines long-term because of your risk for a heart attack, heart failure or heart rhythm issues.

Your outlook depends on how well your heart is working, how bad your artery blockages are and whether you’ve had a heart attack.

How do I take care of myself?

You can take care of yourself by:

• Taking any medicines your provider ordered for you.
• Eating nutritious foods.
• Getting regular physical activity.
• Avoiding tobacco products.
• Managing conditions like diabetes, high blood pressure and high cholesterol.

When should I see my healthcare provider?

You should see your provider when:

• Your heartbeat isn’t normal.
• Your symptoms are happening more often.
• You feel lightheaded.
• You feel pain even when you’re not moving.

When should I go to the emergency room?

Go to the ER or call your local emergency services number (911 in the U.S.) when:

• Your chest pain lasts a long time (more than 15 minutes) or you think you’re having a heart attack.
• Nitroglycerin isn’t working in five minutes (or after three doses).
• Your pain comes back or gets worse.

What questions should I ask my provider?

You may want to ask your provider:

• What lifestyle changes should I make?
• What medicines do I need to take and for how long?
• What are my odds of having a heart attack?`

Is unstable angina a heart attack?

No, but it’s a strong warning sign that you may have a heart attack soon.

Can unstable angina lead to a heart attack?

Yes, it can. If your provider doesn’t clear the blood clot and plaque in your coronary artery, you could have a heart attack.

A note from Cleveland Clinic

The chest pain is back and you’re not sure what to do. Skip the guesswork and get medical help right away. Unstable angina is a warning that you could be having a heart attack before long. Follow your provider’s orders for making changes in your lifestyle and keep taking your medicines. Teaching your family what to watch for and when to call 911 can give you some peace of mind.