How Angina is Diagnosed
To help diagnose the problem, the doctor will review your medical history. You will likely be asked what the discomfort feels like, where it is located, what brings it on and how long it usually lasts.
The doctor will also ask about your past and present illnesses, family history and lifestyle. He or she will particularly inquire about certain factors (such as cigarette smoking and high blood cholesterol) that increase your risk of developing heart disease.
In addition to a medical history, a diagnostic test may be done to check the health of your heart.
The electrocardiogram, or ECG, is a test that records the electrical activity of your heart. Several electrodes (small pads) are placed on your chest, arms, and legs. The heart's electrical impulses cause a needle to trace the heartbeat as a wavy line.
The ECG tracing is a series of waves that represent the electrical events in the heart.
A resting ECG is generally not useful in diagnosing angina, since it is normal (or nearly so) in more than half of patients with stable angina. However, the ECG test is valuable in detecting new heart attacks as well as areas of previously damaged heart muscle.
An exercise ECG test (stress test) allows doctors to learn how well your heart functions when it is made to work harder. This test can help detect heart problems that may not be apparent at rest.
The test is done while you walk on a treadmill or pedal a stationary bicycle. The treadmill starts slowly, then the speed and incline are increased gradually. (If you pedal a stationary bicycle, it feels easy to pedal at first, then it gradually gets harder.)
The occurrence of chest pain during exercise can be compared with changes on the ECG that show the lack of oxygen (ischemia) to the heart muscle. When the patient rests, both the chest pain and ECG changes usually disappear.
An exercise thallium scan is a test that uses a radioactive substance, or tracer, to produce images of the heart muscle. During the test, a small amount of tracer is injected into a vein in your arm while you walk on a treadmill or pedal a stationary bicycle.
The tracer gives off a small amount of radiation that is detected with a scanning camera. A computer processes the information and produces images of blood flow to different regions of the heart.
Reduced blood flow to an area of the heart during stress, with normal flow to the same area at rest indicates significant artery narrowing.
An exercise echocardiogram is a procedure that combines an echocardiogram (ultrasound imaging of the heart) with an exercise test.
When an artery is significantly narrowed, the area of heart muscle supplied by that artery does not pump as well as the rest of the heart during exercise. The abnormalities in muscle contraction can be detected and recorded by the echocardiogram.
(When a patient cannot exercise adequately because of arthritis or other conditions, medications can be injected into a vein to simulate the stress on the heart normally brought on by exercise.)
Cardiac catheterization (or angiogram) is a test that involves the insertion of a catheter (a long, flexible tube) into the body. The catheter is inserted into a vein or an artery and is directed toward the heart. X-ray dye is injected into the heart chambers and/or coronary arteries.
Cardiac catheterization allows doctors to assess the heart's pumping function and take pictures of the coronary arteries. In patients with coronary disease, the pictures indicate where the blockages are and how severe they are. Such information is import in helping doctors select treatment options.