Diagnosis

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 about your symptoms and have your blood pressure, pulse and temperature checked. You'll be connected to a heart monitor and have tests to see if you're having a heart attack.

Tests to diagnose a heart attack include:

• Electrocardiogram (ECG). This first test done to diagnose a heart attack records electrical signals as they travel through your heart. Sticky patches (electrodes) are attached to your chest and limbs. Signals 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 proteins slowly leak into your blood after heart damage from a heart attack. Emergency room doctors will take samples of your blood to check for these proteins, or enzymes.

Additional tests

If you've had or are having a heart attack, doctors will take immediate steps to treat your condition. You might also have 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. Sound waves (ultrasound) create images of the moving heart. Your doctor can use this test to see how your heart's chambers and valves are pumping blood through your heart. An echocardiogram can help identify whether an area of your heart has been damaged.
• 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.
• Cardiac CT or MRI. These tests create images of your heart and chest. Cardiac CT scans use X-rays. Cardiac MRI uses a magnetic field and radio waves to create images of your heart. For both tests, you lie on a table that slides inside a long tubelike machine. Each can be used to diagnose heart problems, including the extent of damage from heart attacks.