Cardiac Testing

Physical Exam and Diagnostic Tests

To determine if you have coronary artery disease or other cardiac conditions, your doctor will do a physical exam that involves checking your cardiovascular system, focusing on heart, lungs, and pulse. Your doctor also will ask you about any symptoms you have, such as chest pain or shortness of breath, and how long, how often, and how severe they are.

Medical tests will be done to find out which arteries are clogged, how much they're clogged, and whether there's any heart damage. Tests may include:
• EKG (electrocardiogram). An EKG is a simple test that detects and records the electrical activity of the heart. This test is used to help detect and locate the source of heart problems. An EKG shows how fast the heart is beating, whether the heart's rhythm is steady or irregular, where in the heart the electrical activity starts, and whether the electrical activity is traveling through the heart in a normal way.
• Stress test. Some heart problems are easier to diagnose when your heart is working harder and beating faster than when it's at rest. During stress testing, you exercise (or are given medicine if you're unable to exercise) to make your heart work harder and beat faster while heart tests are performed.
• During exercise stress testing, your blood pressure and EKG readings are monitored while you walk or run on a treadmill or pedal a bicycle. Other heart tests, such as nuclear heart scanning or echocardiography, also can be done at the same time. These would be ordered if your doctor needs more detailed information on blood flow and the heart's pumping action than the exercise stress test can provide.
• If you are unable to exercise, a medicine can be injected through an intravenous line (IV) into your bloodstream to make your heart work harder and beat faster, as if you are exercising on a treadmill or bicycle. Nuclear heart scanning or echocardiography is then usually done.
• During nuclear heart scanning, radioactive tracer is injected into your bloodstream, and a special camera shows the flow of blood through your heart and arteries. Echocardiography uses sound waves to show blood flow through the chambers and valves of your heart and to show how well your heart pumps.
• Your doctor also may order three newer tests along with stress testing if more information is needed about how well your heart works. These new tests are Magnetic Resonance Imaging (MRI), Cardiac CT Angiography (CTA), and Positron Emission Tomography (PET) scanning of the heart. MRI shows detailed images of the structures and beating of your heart, which may help your doctor better assess if parts of your heart are weak or damaged. CTA scanning shows the anatomic details of the heart arteries and whether any plaque buildup is present. PET scanning shows the level of metabolic activity in different areas of your heart. This can help your doctor determine if enough blood is flowing to the areas of your heart. A PET scan can show decreased blood flow caused by disease or damaged muscles that may not be detected by other scanning methods.
• Echocardiogram. This test uses sound waves to create a moving picture of your heart. Echocardiogram provides information about the size and shape of your heart and how well your heart chambers and valves are functioning. The test also can 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.
• There are several different types of echocardiograms, including a stress echocardiogram. During this test, an echocardiogram is done both before and after your heart is stressed either by having you exercise or by injecting a medicine into your bloodstream that makes your heart beat faster and work harder. A stress echocardiogram is usually done to find out if you have decreased pumping action of your heart (CAD).
• Angiography. Angiography uses a special dye injected into the bloodstream to outline the insides of arteries on x-ray pictures. An angiogram shows the location and severity of blockages in blood vessels.

Written by Dr. Mark Steiner, Cardiologist in Orlando