Tests & Diagnosis of Heart Disease

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

If you're having a heart attack or suspect you're having one, your diagnosis will likely happen in an emergency setting. You'll be asked to describe your symptoms and will have your blood pressure, pulse and temperature checked. You'll be hooked up to a heart monitor and will almost immediately start to have tests done to see if you are indeed having a heart attack.

The medical staff will listen to your heart and lung sounds with a stethoscope. You'll be asked about your health history and the history of heart disease in your family. The tests your doctors order will help check if your signs and symptoms, such as chest pain, signal a heart attack or another condition.

These tests include:
Electrocardiogram (ECG). This is the first test done to diagnose a heart attack. It's often done while you are being asked questions about your symptoms. This test 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 and shape of your heart and its blood vessels.

Echocardiogram. This test uses sound waves to produce an image of your heart. During an echocardiogram, sound waves are directed at your heart from a transducer, a wand-like device, held on your chest. The sound waves bounce off your heart and are reflected back through your chest wall and 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.

Nuclear scan. This test helps identify blood flow problems to your heart. Small amounts of radioactive material are injected into your bloodstream. Special cameras can detect the radioactive material as it flows through your heart and lungs. Areas of reduced blood flow to the heart muscle — through which less of the radioactive material flows — appear as dark spots on the scan.

Coronary catheterization (angiogram). This test can show if your coronary arteries are narrowed or blocked. 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, to the arteries in your heart. As the dye fills your arteries, the arteries become visible on X-ray, revealing areas of blockage. Additionally, while the catheter is in position, your doctor may treat the blockage by performing an angioplasty, also known as coronary artery balloon dilation, balloon angioplasty and percutaneous coronary intervention. Angioplasty uses tiny balloons threaded through a blood vessel and into a coronary artery to widen the blocked area. In most cases, a mesh tube (stent) is also placed inside the artery to hold it open more widely and prevent re-narrowing in the future.

Exercise stress test. In the days or weeks following 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.

Stress tests help doctors decide the best long-term treatment for you. If your doctor also wants to see images of your heart while you're exercising, he or she may order a nuclear stress test, which is similar to an exercise stress test, but uses an injected dye and special imaging techniques.

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 tube-like 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.

Tilt Table Test. The head-up tilt table test is used to help find the cause of fainting spells. The test involves lying quietly on a bed and being tilted at different angles (30 to 60 degrees) for a period of time while various machines monitor your blood pressure, electrical impulses in your heart, and your oxygen level. The head-up tilt table test is performed in a special room called the EP (electrophysiology) lab.

Electrophysiology Test
Electrophysiology -- the EP test -- takes measurements of your heart rhythm -- recording the electrical activity and pathways of your heart. An electrophysiology (EP) study is a test that records the electrical activity and the electrical pathways of your heart. This test is used to help determine the cause of your heart rhythm disturbance and the best treatment for you. During the EP study, your doctor will safely reproduce your abnormal heart rhythm and then may give you different medications to see which one controls it best or to determine the best procedure or device to treat your heart rhythm.

Myocardial Biopsy
A myocardial biopsy is when a doctor uses a special catheter to remove a piece of your heart tissue for examination. A heart biopsy, also called myocardial biopsy or cardiac biopsy, is an invasive procedure to detect heart disease that involves using a bioptome (a small catheter with a grasping device on the end) to obtain a small piece of heart muscle tissue that is sent to a laboratory for analysis.

Heart MRI
A heart MRI is a great way for doctors to get a look -- from the outside -- at how your heart is working. One test used for evaluation of heart disease is MRI (magnetic resonance imaging). MRI uses large magnets and radio-frequency waves to produce pictures of the body's internal structures; no X-ray exposure is involved. This technique obtains information about the heart as it is beating, creating images of the heart throughout its pumping cycle.

Pericardiocentesis
Pericardiocentesis, also called a pericardial tap, is an invasive procedure that involves using a needle and catheter to remove fluid (called a pericardial effusion) from the sac around the heart (the pericardium). The fluid may then be sent to a laboratory for tests to look for signs of infection or cancer.

Occasionally, pericardiocentesis is performed on an emergency basis to treat a condition called cardiac tamponade. This condition is a life-threatening, rapid buildup of fluid around the heart that puts pressure on the heart muscle, weakening its pumping ability.

Sources: Mayo Clinic, WebMD