Covers angina and symptoms that happen when the heart does not get enough blood. Covers unstable angina and heart attack. Discusses treatment with medicines, angioplasty, or bypass surgery. Offers prevention tips.
Acute Coronary Syndrome
What is acute coronary syndrome?
syndrome happens when the heart is not getting enough blood. It is an emergency. It includes
unstable angina and
coronary arteries supply oxygen-rich blood to the
heart muscle. If these arteries are narrowed or blocked, the heart does not get
enough oxygen. This can cause angina or a heart attack.
Unstable angina is
chest pain or discomfort from lack of blood flow, but there is no damage to the heart muscle.
It often happens when you are at rest. You may have had
stable angina before. You knew when to expect your symptoms, such as when you exercised. Stable angina usually goes away
when you rest or take your angina medicine. But the symptoms of unstable angina may
not go away with rest or medicine. It may get worse or happen at times that it
didn't before. Unstable angina is not a heart attack. But it is a warning that
a heart attack could happen soon, so it needs to be treated right
A heart attack means a coronary artery
has been blocked and the heart has been damaged. Without blood flow and oxygen,
part of the heart starts to die.
Any type of acute coronary syndrome is very serious and
needs to be treated right away.
What causes acute coronary syndrome?
coronary syndrome happens because
plaque narrows or blocks the arteries that supply
blood to the heart. Plaque is made of
cholesterol and other things. Over time, plaque can
build up in the arteries. This is known as
atherosclerosis. When it happens in coronary arteries, it is called coronary artery disease.
Plaque causes angina by narrowing the
arteries. The narrowing limits blood flow to the heart muscle. A heart attack happens when blood flow is completely blocked.
What are the symptoms?
Call 911 or other emergency services immediately if you have symptoms of acute coronary syndrome. These may include:
Chest pain or pressure, or a strange feeling in the chest.
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.
After you call 911, the operator may tell you to chew 1 adult-strength or 2 to 4 low-dose aspirin. Wait for an ambulance. Do not try to drive yourself.
How is acute coronary syndrome diagnosed?
will give you a physical exam and ask about your symptoms and past health. He
or she also will ask about your family's health. You will have several tests to
find out what is causing your chest pain.
electrocardiogram can show whether you have angina or
have had a heart attack. This test measures the electrical signals that control
your heart's rhythm. Small pads will be taped to your chest and other areas of
your body. They connect to a machine that traces the signals onto paper. The
doctor will look for certain changes on the graph to see if your heart is not
getting enough blood or if you are having a heart attack.
test will look for a rise in cardiac enzymes. The heart releases these
substances when it is damaged.
In some cases, you might have a
test called a cardiac perfusion scan to see if your heart is getting enough
blood. It also can be used to check for areas of damage after a heart
How is it treated?
If you call
911, treatment will start in the ambulance
with aspirin and other medicines.
In the hospital, the doctor will
work right away to return blood flow to your heart. You may get medicines to break up and prevent blood clots. You may get nitroglycerin
and other medicines that make your arteries wider. This helps to ease pain and
improve blood flow. You also will get oxygen and pain medicine.
Your test results will help your doctor decide about more treatment. If
you are having a heart attack, you likely will get medicines to break up clots
angioplasty (usually with
bypass surgery to improve blood flow to your heart. If
you are having unstable angina, you will likely get medicines but you might
also have angioplasty with stents.
After you get out of the
hospital, you will continue to take medicines that lower your risk of a heart attack. Medicine may include beta-blockers, aspirin or other medicines to prevent blood clots, blood pressure medicine, and statins for cholesterol.
Can acute coronary syndrome be prevented?
A heart-healthy lifestyle can help prevent heart disease, which can lead to acute coronary syndrome. If you already have heart disease, a heart-healthy lifestyle along with medicine can help prevent a heart attack.
Eat a heart-healthy diet that has lots of fruit,
vegetables, whole grains, and lean protein.
Stay at a healthy
weight. Lose weight if you need to.
Be active. Your doctor can suggest a safe level of exercise for you.
Manage other health problems, including diabetes, high blood pressure, and high cholesterol.
Lower your stress level. Stress can damage your heart.
Take a daily aspirin if your doctor advises it.
Other Places To Get Help
American College of Cardiology: CardioSmart
American Heart Association (AHA)
NIH: National Heart, Lung, and Blood Institute (U.S.)
Antman EM (2012). ST-elevation myocardial infarction: Pathology, pathophysiology, and clinical features. In RO Bonow et al., eds., Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 9th ed., vol. 2, pp. 1087–1110. Philadelphia: Saunders.
Jneid H, et al. (2012). 2012 ACCF/AHA Focused update of the guideline for the management of patients with unstable angina/non-ST-elevation myocardial infarction (updating the 2007 guideline and replacing the 2011 focused update): A report of
the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation, 126(7): 875–910.
Kim MC, et al. (2011). Definitions of acute coronary syndromes. In V Fuster et al., eds., Hurst's the Heart, 13th ed., vol. 2, pp. 1287–1295. New York: McGraw-Hill.
O'Connor RE, et al. (2010). Acute coronary syndromes: 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation, 122(18): S787–S817.
Sarkees ML, Bavry AA (2010). Non ST-elevation acute coronary syndrome, search date December 2009. BMJ Clinical Evidence. Available online: http://www.clinicalevidence.com.
Thygesen K, et al. (2012). Third universal definition of myocardial infarction. Circulation, 126(16): 2020–2035. Also available online: http://circ.ahajournals.org/content/126/16/2020.
Primary Medical Reviewer
Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology
Specialist Medical Reviewer
Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology
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