Diagnostic Tests for Coronary Artery Disease
Many tests help to diagnose Coronary Artery Disease (CAD). Usually, your doctor will order more than one test before making a definite diagnosis.
Tests May Include:
- Electrocardiogram (ECG or EKG) An EKG is a simple test that detects and records the electrical activity of the heart. It shows how fast your heart is beating and whether it has a regular rhythm. It also shows the strength and timing of electrical signals as they pass through each part of your heart, and any heart muscle damage.
- Stress Test During a stress test, you exercise to raise your heart rate while heart tests are performed. If you can’t exercise, you’re given medication to speed up your heart rate.
When your heart is beating fast and working hard, it needs more blood and oxygen. Arteries narrowed by plaque can’t supply enough oxygen-rich blood to meet your heart’s needs. A stress test can show possible signs of CAD, such as:
- Abnormal changes in your heart rate or blood pressure
- Symptoms such as shortness of breath or chest pain
- Abnormal changes in your heart rhythm or your heart’s electrical activity
During the stress test, if you can’t exercise for the time considered normal for someone your age, it may be a sign that not enough blood is flowing to your heart. But other factors besides CAD can also prevent you from exercising effectively (for example, lung disease, anemia, or poor general fitness).
- Echocardiography (Echocardiogram) This test uses sound waves to create a moving picture of your heart. It can provide information about the size and shape of your heart and how well your heart chambers and valves are working.
This test can also identify areas of poor blood flow to the heart, areas of heart muscle that are not contracting normally, and previous injury to the heart muscle caused by poor blood flow.
- Nuclear Scanning During this scan, radioactive material is put into a vein and watched by a special camera. This test shows the healthy and damaged areas of the heart.
- Coronary Angiography/Cardiac Catheterization This test uses dye and special x-rays to show and evaluate the insides of your coronary arteries. Your doctor may ask you to have this done if other tests or factors show that you’re likely to have CAD.
To get the dye into the coronary arteries, a long, thin, flexible tube called a catheter is put into a blood vessel in your arm, groin, or neck. This tube is then threaded into your coronary arteries, and the dye is released into your bloodstream. Special x-rays are taken while they dye is flowing through your coronary arteries.
- CT angiography This test is a noninvasive way to perform coronary angiography.
- Electron-Beam Computed Tomography (EBCT) This test finds and measures calcium deposits in and around the coronary arteries. The more calcium detected, the more likely you are to have CAD. EBCT is not used routinely to diagnose CAD, because its accuracy is not yet known.