Acute Coronary Syndrome: Diagnosis

Doctors diagnose acute coronary syndrome (ACS) based on the results of an electrocardiogram (EKG) and the presence of substances in the blood (serum markers) released by the damaged heart. The classification is important because treatments differ depending on the specific acute coronary syndrome.

If you have signs and symptoms of ACS, your doctor may run several tests to see if your symptoms are caused by a heart attack or another heart-related problem.

  • Electrocardiogram (EKG). This is the first test done to diagnose a heart attack. It's often done while you are being asked questions about your symptoms. The EKG may show that a heart attack has occurred or is in progress.
  • Blood tests. Certain heart enzymes slowly leak into your blood if your heart has been damaged by a heart attack.

Your doctor may also order some of these additional tests:

  • Echocardiogram. If you haven't had a heart attack and your risk of having a heart attack is low, you'll likely have this painless sonogram-like test completed before you leave the hospital. It provides an onscreen visual of your working heart.
  • Chest x-ray. An x-ray image of your chest allows your doctor to measure the size and shape of your heart and its blood vessels.
  • Nuclear scan. This test helps identify blood flow problems to your heart.
  • Computerized tomography (CT) angiogram. A CT angiogram allows your doctor to check your arteries to see if they're narrowed or blocked.
  • Coronary angiography. This test involves injecting a dye into your arteries to determine if your coronary arteries are narrowed or blocked.