Tests and diagnosis

By Mayo Clinic Staff

Ideally, your doctor should screen you during regular physical exams for risk factors that can lead to a heart attack.

If you're in an emergency setting for symptoms of a heart attack, you'll be asked to describe your symptoms and have your blood pressure, pulse and temperature checked. You'll be hooked up to a heart monitor and will almost immediately have tests to see if you're having a heart attack.

Tests will help check if your signs and symptoms, such as chest pain, indicate a heart attack or another condition. These tests include:

  • Electrocardiogram (ECG). This first test done to diagnose a heart attack records the electrical activity of your heart via electrodes attached to your skin. Impulses are recorded as waves displayed on a monitor or printed on paper. Because injured heart muscle doesn't conduct electrical impulses normally, the ECG may show that a heart attack has occurred or is in progress.
  • Blood tests. Certain heart enzymes slowly leak out into your blood if your heart has been damaged by a heart attack. Emergency room doctors will take samples of your blood to test for the presence of these enzymes.

Additional tests

If you've had a heart attack or one is occurring, doctors will take immediate steps to treat your condition. You may also undergo these additional tests:

  • Chest X-ray. An X-ray image of your chest allows your doctor to check the size of your heart and its blood vessels and to look for fluid in your lungs.
  • Echocardiogram. During this test, sound waves directed at your heart from a wandlike device (transducer) held on your chest bounce off your heart and are processed electronically to provide video images of your heart. An echocardiogram can help identify whether an area of your heart has been damaged by a heart attack and isn't pumping normally or at peak capacity.
  • Coronary catheterization (angiogram). A liquid dye is injected into the arteries of your heart through a long, thin tube (catheter) that's fed through an artery, usually in your leg or groin, to the arteries in your heart. The dye makes the arteries visible on X-ray, revealing areas of blockage.
  • Exercise stress test. In the days or weeks after your heart attack, you may also undergo a stress test. Stress tests measure how your heart and blood vessels respond to exertion. You may walk on a treadmill or pedal a stationary bike while attached to an ECG machine. Or you may receive a drug intravenously that stimulates your heart similar to exercise.

    Your doctor may also order a nuclear stress test, which is similar to an exercise stress test, but uses an injected dye and special imaging techniques to produce detailed images of your heart while you're exercising. These tests can help determine your long-term treatment.

  • Cardiac computerized tomography (CT) or magnetic resonance imaging (MRI). These tests can be used to diagnose heart problems, including the extent of damage from heart attacks. In a cardiac CT scan, you lie on a table inside a doughnut-shaped machine. An X-ray tube inside the machine rotates around your body and collects images of your heart and chest.

    In a cardiac MRI, you lie on a table inside a long tubelike machine that produces a magnetic field. The magnetic field aligns atomic particles in some of your cells. When radio waves are broadcast toward these aligned particles, they produce signals that vary according to the type of tissue they are. The signals create images of your heart.

Nov. 15, 2014

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