Acute Coronary Syndrome



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 very much reduced or fully blocked. This leads to heart muscle damage or death from a heart attack.

Narrowing in the arteries most often happens from years of plaque buildup in them. This is called atherosclerosis. Blood clots may also cause the arteries to get more narrow.

Coronary Artery
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Risk Factors

ACS is more common in men who are at least 45 years of age and in women who are at least 55 years of age.

Other things that may raise the risk of ACS are:

  • A family history of heart disease
  • Being overweight or obese
  • Smoking
  • High cholesterol, especially high LDL cholesterol, high triglycerides, and low HDL cholesterol
  • High blood pressure
  • Diabetes
  • Inactivity
  • Current angina, a previous heart attack, or other types of heart disease



ACS is serious. People should call for emergency medical services right away if they have:

  • Chest pain, pressure, tightness, burning, or other discomfort that may last a few minutes, go away, and then come back
  • Pain that last 30 minutes and happens:
  • At rest or while being active, or while sleeping
  • After emotional stress
  • After eating a large meal
  • With shortness of breath
  • Pain or discomfort in one or both arms, shoulders, the back, the neck, jaw, or stomach
  • Lightheadedness
  • Nausea and vomiting
  • Sweating


The doctor will ask about symptoms and health history. A physical exam will be done.

Blood tests may be done.

Tests may be done to see how well the heart is working, such as:

  • ECG
  • Nuclear heart scan
  • Cardiac catheterization

Images of the heart may need to be taken with:

  • Coronary angiography
  • Echocardiogram
  • CT angiography



The goals of treatment for a person who is having a heart attack are to:

  • Quickly restore blood flow to the heart
  • Treat any problems the heart attack may cause

To help with blood flow, doctors may give:

  • Aspirin to help keep blood from clotting and forming more blockages.
  • Anti-ischemic drugs, such as nitroglycerin, to help ease chest pain.
  • Beta-blockers to slow the heart rate so it does not use too much energy.
  • Thrombolytic drugs to dissolve blood clots. When given soon after a heart attack begins, these drugs can limit or prevent lasting damage to the heart. To work well they need to be given within 1 hour after the start of heart attack symptoms.
  • Platelet inhibitors to keep the blockage from getting worse.
  • Oxygen—Hyperbaric oxygen therapy may be used.

Other treatments may be needed to help the heart. These could include:

  • Angioplasty—A catheter is inserted into a blocked artery. A balloon is inflated and deflated. This will help blood flow again. A stent may be placed to prop the artery open.
  • Coronary artery bypass surgery—Arteries or veins are taken from other areas of the body. They are used to bypass the blocked arteries in the heart.
  • Prevention

    To help reduce the chances of ACS:

    • Eat a well-balanced diet that is low in saturated fats. The diet should also be rich in fruits, vegetables, and whole grains.
    • Work out regularly.
    • Do not smoke or vape. Talk to the doctor about ways to quit.
    • Manage health issues like diabetes, blood pressure, and cholesterol. This can mean taking medicine or making lifestyle changes.

    This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

    Edits to original content made by Denver Health.