Diagnosing a Heart Attack

Updated:Jan 11,2018

 Testing your heart's performance

What to Expect
The hours following a heart attack can be scary and confusing. Your medical team may be so busy working to get you better that no one can stop and explain what’s going on. So, your first question might be, “What just happened?!”

That’s a totally normal response. It’s OK to ask lots of questions. Your doctors will have questions, too, as they seek to diagnose the underlying causes of your heart attack.

This page previews the kinds of diagnostic procedures you will likely encounter as your doctors strive to pinpoint the exact health conditions affecting your heart’s performance.

We will:

  • Explain two basic types of heart attack and some standard diagnostic steps.
  • Walk you through common questions and answers.
  • Suggest some additional questions you might want to ask your doctor.

Heart Attack Types & 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 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 would be an ‘NSTEMI’ heart attack — a non-ST-elevation myocardial infarction.

Diagnostic steps differ for a STEMI versus NSTEMI heart attack, although there can be some overlap.

Some hospitals use a procedure called percutaneous coronary intervention (PCI), a mechanical means of treating heart attack. About 36% of hospitals in the U.S. are equipped to use PCI.  

At a hospital that uses PCI, you would likely be sent to the department that specializes in cardiac catheterization (usually called a cath lab) for a diagnostic angiogram to examine blood flow to your heart and test how well the heart is pumping.

A hospital that does not use PCI might transfer you to one that does. Or, it may decide to administer drugs known as fibrinolytic agents to restore blood flow. You might be given an angiography (an imaging technique used to see inside your arteries, veins and heart chambers).

IMPORTANT: 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.

Answers to Common Questions
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: Where can I see the big picture? How does all this fit together for me?
A: See Diagnostic Tests and Procedures At-A-Glance to better understand the tests you may have to undergo to find out 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: See our Treatment of Heart Attack page. If you've had a heart attack, you may have already had certain procedures to help you survive your heart attack and diagnose your condition.

  • Thrombolysis: Many heart attack patients have undergone 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 done 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.

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 with any questions you 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’ — and when can I start?

This content was last reviewed June 2016.

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