Diagnosing a Heart Attack

nurse giving instructions to patient

Testing: what to expect

The hours following a heart attack can be scary and confusing. Your medical team may be incredibly busy and focused, and hard-pressed to explain everything that’s happening.

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

In the section below, you’ll find descriptions of the kinds of diagnostic procedures you may encounter as your doctors strive to identify the underlying causes of your heart attack.

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 means you suffered a STEMI heart attack – which stands for ST-elevation myocardial infarction.
  • A partial blockage translates to an NSTEMI heart attack – a non-ST-elevation myocardial infarction.

Diagnostic steps differ for STEMI and NSTEMI heart attacks, although there can be some overlap. 

Remember: Never try to diagnose yourself. Always dial 911 if you think you might be having a heart attack. The EMS crew in your ambulance will route you to the right hospital based on your location.

Heart attack testing: FAQ

Q: Why do I have to submit to a bunch of tests?
A: Tests help the doctor 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 screen your heart and help the doctor determine what treatment and lifestyle changes will keep your heart healthy and prevent serious future medical events.

Q: What’s the difference between “invasive” and “non-invasive” tests?
A: Non-invasive cardiac tests measure your heart’s activity through external imaging and electrocardiography. Invasive tests include drawing and testing samples of your blood, and inserting and threading a thin hollow tube called a catheter into a blood vessel to get an inside view.

Q: How can I learn more about the tests that may be performed?
A: These diagnostic tests and procedures can reveal if you had a heart attack, how much damage was done and what degree of coronary artery disease (CAD) you have.

Q: What types of treatment will I get after the hospital diagnoses my heart attack?
A: If you’ve had a heart attack, you may have already had undergone certain procedures to help you survive your heart attack. Those same procedures can help to diagnose your condition. Such procedures include:

  • Thrombolysis: Many 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 heart attack.
  • Coronary angioplasty/coronary artery bypass graft surgery (CABG): If thrombolysis treatment isn’t administered immediately after a heart attack, many patients will need to undergo coronary angioplasty or coronary artery bypass graft surgery (CABG) later to improve blood supply to the heart muscle.

Learn more about the treatment of heart attack.

Additional questions for your doctor

Doctors are busy, but they really want to help you. You can help them do so by coming to each appointment prepared. Bring any questions you may have about your diagnosis, your treatment or other elements of your medical care.

Here are some examples of questions heart attack patients often have during the heart attack diagnosis process.

  • What kind of heart attack did I have?
  • Did it damage my heart permanently?
  • Why did this happen to me?
  • Am I at risk of having another one soon?
  • Could you explain the treatments and medicines I’ll need?
  • Should I worry about how my medicines will interact or side effects?
  • How long will I have to stay in the hospital?
  • What physical limitations will I have while recovering?
  • Will I be able to return to a normal life?
  • What is “cardiac rehab”? When can I start?

Watch, Learn and Live

See your cardiovascular system in action with our interactive illustrations and animations.