Acute Coronary Syndrome
(ACS; Unstable Angina)
by Sid Kirchheimer
Acute coronary syndrome (ACS) is a set of features related to poor blood flow to the heart muscle that leads to a heart attack. This results in angina. ACS is a serious, life-threatening condition. If you think you have ACS, seek emergency medical treatment.
ACS is caused by a sudden blockage of the coronary arteries. These blood vessels carry blood to the heart muscle. The blood flow to the heart muscle is either greatly reduced or completely blocked. This leads to heart muscle damage or death from a heart attack.
The narrowing most often happens from years of plaque buildup in an artery. This is called atherosclerosis. Blood clots may often cause the narrowing arteries.
ACS is more common in men over 45 years old and women over 55 years old.
Other factors that may increase your chances of ACS:
ACS is serious. Call for emergency medical services if you have:
You will be asked about your symptoms and medical history. A physical exam will be done.
Your bodily fluids may need to be tested. This can be done with blood tests.
Your heart function may need to be tested. This can be done with:
Detailed images of your heart may need to be taken. These can be done with:
If you are having a heart attack, doctors will:
To restore blood flow, the main treatments are:
To help reduce your chances of ACS:
American Heart Association
CardioSmart—American College of Cardiology
Canadian Cardiovascular Society
Heart and Stroke Foundation of Canada
Acute coronary syndromes. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated August 22, 2017. Accessed September 15, 2017.
Explore angina. National Heart, Lung, and Blood Institute website. Available at: https://www.nhlbi.nih.gov/health/health-topics/topics/angina. Updated June 1, 2011. Accessed September 15, 2017.
Revascularization for acute coronary syndromes. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated Accessed December 7, 2016. September 15, 2017.
Tips for recovering and staying well after a heart attack. Family Doctor—American Academy of Family Physicians website. Available at: https://familydoctor.org/tips-for-recovering-and-staying-well. Updated June 2017. Accessed September 15, 2017.
8/17/2015 DynaMed Plus Systematic Literature Surveillance http://www.dynamed.com/topics/dmp~AN~T116779/Acute-coronary-syndromes : Bennett MH, Lehm JP, Jepson M. Hyperbaric oxygen therapy for acute coronary syndrome. Cochrane Database Syst Rev. 2015;(7):CD004818.
Last reviewed September 2018 by EBSCO Medical Review Board Michael J. Fucci, DO, FACC
Last Updated: 8/17/2015
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