An ECG records the heart's electrical activity. A healthy heart creates a specific pattern on an ECG. The pattern will change during or after a heart attack. It will show if the heart attack is:

Non-STEMI (NSTEMI)—caused by a partial blockage
STEMI—caused by a total blockage

It can also show what part of the heart is not working as it should.

Other tests will be done to confirm there was a heart attack:

Blood Tests

Blood tests look for markers of a heart attack. Certain items are found in the blood within hours or days after a heart attack. Blood tests may need to be repeated in order to track the treatment and recovery progress.

Troponins—High levels suggest heart damage. Higher the level the more damage there is. These levels increase within hours of a heart attack. They can stay elevated for days after a heart attack.
Other factors that increase in the blood if muscle (any muscle not just the heart) is damaged:
- Creatine kinase (CK)
- Myoglobin

Angiography

An angiography can closely look at the blood flow through a blood vessel. A catheter is threaded through an artery in the groin or wrist. It is passed up to the arteries that feed the heart. A dye is passed through the catheter. It will highlight the blood vessels on a screen in the room. The doctor will be able to see where blood flow is reduced or blocked.

Narrowed or blocked arteries can be opened during the test. It may be pressed open with a balloon, stent, or other procedure.

Tests to Check Heart Damage

Other tests will be needed to look for damage to the heart. Tests may include:

Chest x-ray —To looks for signs of heart failure.
Exercise stress test—Records the heart's electrical activity during physical activity. It can show how the heart responds to stress or if blood supply is not enough to support increased workload. People who cannot exercise may be given medicine that has the same effect on the heart.
Echocardiogram—Shows movement of heart muscle and blood flow. Looks for problems in the heart muscle by highlighting areas of poor blood flow.
MRI scan—May be needed if echocardiogram is not clear.

References:

Acute coronary syndromes. EBSCO DynaMed Plus website. Available at: http://www.dynamed.... Updated March 15, 2019. Accessed March 28, 2019.

Acute myocardial infarction (MI). Merck Manual Professional Version website. Available at: https://www.merckmanuals.com/professional/cardiovascular-disorders/coronary-artery-disease/acute-myocardial-infarction-mi. Updated December 2018. Accessed March 28, 2019.

ST-elevation myocardial infarction (STEMI). EBSCO DynaMed Plus website. Available at: http://www.dynamed.... Updated July 10, 2018. Accessed March 28, 2019.

Symptoms and diagnosis of heart attack. American Heart Association website. Available at: https://www.heart.org/en/health-topics/heart-attack/diagnosing-a-heart-attack. Accessed March 28, 2019.

Last reviewed March 2019 by EBSCO Medical Review Board Michael J. Fucci, DO, FACC
Last Updated: 3/28/2019

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