Diagnosing a Heart Attack

The hours following a heart attack can be scary and confusing. Your medical team may be busy and focused, and don’t have time to explain everything that’s happening in the moment. Your health care team is trying to identify the type of heart attack you’ve had and determine the best treatment options.

You and your family members are sure to have questions. You may wonder about the tests and procedures that are being performed.

Heart attack types and diagnosis

A heart attack is also called a myocardial infarction, sometimes simply referred to as an “MI.” A heart attack occurs when a blockage in one or more coronary arteries reduces or stops blood flow to the heart, which starves part of the heart muscle of oxygen.

The blood vessel blockage might be complete or partial:

• A complete blockage of a coronary artery is a ST-elevation myocardial infarction (STEMI).
• A partial blockage is a non-ST-elevation myocardial infarction (NSTEMI).

Diagnostic tests and procedures help your medical team determine if a heart attack occurred, how much your heart was damaged and what degree of coronary artery disease (CAD) you might have. The tests help the health care team determine what treatment is needed and what lifestyle changes will help you improve your heart health and prevent future medical events.

Non-invasive diagnostic testing involving imaging may include a needle stick such as for an intravenous injection of a contrast agent. Invasive procedures can include insertion of a tube, device or scope, and blood tests.

Blood testing may include the following:
Cardiac enzymes (including troponin and creatine kinase), C-reactive protein (CRP), fibrinogen, homocysteine, lipoproteins, triglycerides, brain natriuretic peptide (BNP) and prothrombin.

Reason for Test

• Confirms that a heart attack has occurred and determines extent of damage.
• Assesses future risk for coronary artery disease.
• Provides information on the time it takes for the blood to clot.

If you’ve had a heart attack, you may have already undergone certain procedures to help you survive. Those same procedures can help diagnose your condition. Such procedures include: 

• Thrombolysis: Many STEMI heart attack patients will undergo thrombolysis, a procedure that involves injecting a clot-dissolving agent to restore blood flow in a coronary artery. This procedure is administered within a few (usually three) hours of a STEMI heart attack.
• Coronary angioplasty/coronary artery bypass graft surgery (CABG): If thrombolysis treatment isn’t administered immediately after a heart attack, many people will need to undergo coronary angioplasty and stenting or CABG to improve blood supply to the heart muscle.

Learn more about the treatment of heart attack.