Tests Used to Diagnose a Heart Attack
Medical testing is critical when you or a loved one has chest pain or other symptoms of a heart attack . Your doctor will use a variety of tests to make a diagnosis. Having multiple tests can be challenging, but most of the tests for heart attack are not painful and provide your doctor with valuable information about your heart.
Your heart is made of muscle. All muscles need oxygen to function normally. A heart attack (myocardial infarction) is caused by a blockage in an artery—coronary artery—that brings oxygen-rich blood to your heart muscle. Without quick treatment to open the blockage, serious or permanent heart damage will occur. Tests for heart attack look for blocked coronary arteries and signs of heart damage caused by a heart attack.
If you have sudden symptoms of a heart attack, such as chest pain, your healthcare team will perform these initial tests:
EKG (also called an electrocardiogram, or ECG): Electrical impulses trigger your heartbeat. An EKG makes a picture of the electrical activity of your heart. During a heart attack, your damaged heart may not conduct electrical impulses normally. This appears as abnormal waves on your EKG. An EKG is painless and only takes a few minutes. It involves attaching sticky-backed electrodes to your chest.
Blood enzymes tests (cardiac enzymes tests): Heart damage due to a heart attack causes certain enzymes (proteins) to leak from your heart muscle into your blood. The blood test for the enzyme troponin is the most accurate. It only takes a few minutes.
After your doctor sees the results of the initial tests above, he or she may order the following tests to help diagnose a heart attack or other types of heart disease:
This procedure involves inserting a tiny tube (catheter) into a blood vessel in your neck, groin or arm and guiding it to your heart. Your doctor will inject dye into the catheter and take X-ray images, watching how the dye moves through your coronary arteries. You will feel the needle prick to numb the insertion point. You may also feel pressure as the catheter moves. Your doctor may also perform an angioplasty at this time to clear blocked arteries. A small tubular stent may be implanted to keep the formerly clogged artery open.
Echocardiogram: This is a painless test that uses sound waves to make a picture of your heart. An echocardiogram can show if your heart isn't pumping normally. It can also help your doctor determine if a heart attack has damaged your heart.
An echocardiogram involves holding a wand-like device (transducer) on your chest. The transducer produces sound waves that bounce off your heart and back though your chest. The echocardiogram machine picks up the waves and converts them into video images of your heart.
Exercise stress test: This test helps your doctor judge how exercise affects your heart and how well blood flows through your coronary arteries. An exercise stress test involves watching your blood pressure, heart rate, and possible changes on your EKG as you exercise on a treadmill. Instead of exercising, some people may receive a drug through an IV to quicken the heart.
Noninvasive coronary angiography: This test uses computed tomography (CT) or magnetic resonance imagining (MRI) to create images of your coronary arteries. The test shows the severity of blockage or narrowing in your arteries. The test is painless. You may receive an injection of dye (contrast) through an IV to produce clearer pictures.
Nuclear stress test: This stress test involves injecting a radioactive substance, such as thallium, through an IV. The doctor takes pictures of your heart while you rest and during exercise. The radioactive substance, called an isotope, shows up lighter in areas of the heart with good blood flow better than areas with poor circulation due to a blocked coronary artery.
After a heart attack diagnosis, you may remain in the hospital for a few days or longer depending on your treatment. For example, angioplasty to clear a blocked artery requires one to two days in the hospital and coronary artery bypass surgery usually requires about 10 days in the hospital.