Heart attack - ACS; Myocardial infarction - ACS; MI - ACS; Acute MI - ACS; ST elevation myocardial infarction - ACS; Non ST-elevation myocardial infarction - ACS; Unstable angina - ACS; Accelerating angina - ACS; Angina - unstable-ACS; Progressive angina
Acute coronary syndrome is a term for any condition that suddenly stops (or severely reduces) blood from flowing to the heart. When blood cannot flow to the heart, the heart muscle can become damaged. Heart attack and unstable angina are both acute coronary syndromes (ACS).
A fatty substance called plaque can build up in the arteries that bring oxygen-rich blood to your heart. Plaque is made up of cholesterol, fat, and other waste products.
Plaque can block blood flow in 2 ways:
Many risk factors for heart disease may lead to an ACS.
The most common symptom of ACS is chest pain. The chest pain may come on quickly, come and go, or get worse with rest. Other symptoms can include:
Women and older people often experience these other symptoms, although chest pain is common for them as well.
Your health care provider will do an exam, listen to your chest with a stethoscope, and ask about your medical history.
Tests for ACS include:
Coronary angiography may be done right away or when you are more stable. This test:
Other tests to look at your heart that may be done while you are in the hospital include:
Your provider may use medicines, surgery, or other procedures to treat your symptoms and restore blood flow to your heart. Your treatment depends on your condition and the amount of blockage in your arteries. Your treatment may include:
How well you do after an ACS depends on:
In general, the quicker your artery gets unblocked, the less damage you will have to your heart. People tend to do best when the blocked artery is opened within a few hours from the time symptoms start.
In some cases, ACS can lead to other health problems including:
An ACS is a medical emergency. If you have symptoms, call 911 or your local emergency number quickly.
There is a lot you can do to help prevent ACS.
Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: a report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;64(24)O:e139-e228. PMID: 25260718
Eckel RH, Jakicic JM, Ard JD, et al. 2013 AHA/ACC guideline on lifestyle management to reduce cardiovascular risk: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014;129(25 Suppl 2):S76-S99. PMID: 24222015
O'Gara PT, Kushner FG, Ascheim DD, et al. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation. 2013;127(4):529-555. PMID: 23247303
Smith SC Jr, Benjamin EJ, Bonow RO, et al. AHA/ACCF secondary prevention and risk reduction therapy for patients with coronary and other atherosclerotic vascular disease: 2011 update: a guideline from the American Heart Association and American College of Cardiology Foundation. Circulation. 2011;124(22):2458-2473. PMID: 22052934
Last reviewed on: 5/5/2016
Reviewed by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.