Cardiac Diagnostic Tests

New tests are constantly being developed to further the understanding of disease, injury, and congenital (present at birth) or acquired abnormalities of the heart. These are just a few of the tests that have been used to diagnose heart and blood vessel disease (cardiovascular). For more information, talk to your cardiologist or other healthcare provider:

• Electrocardiogram (ECG). This test records the electrical activity of the heart, shows abnormal rhythms (arrhythmias), and can sometimes detect heart muscle damage.

• Stress test ( also called treadmill or exercise ECG). This test is done to monitor the heart while you walk on a treadmill or pedal a stationary bike. Your doctor also monitors your breathing and blood pressure. A stress test may be used to detect coronary artery disease, or to determine safe levels of exercise after a heart attack or heart surgery. This test can also be done using special medicines that stress the heart in a similar manner as exercise does.

• Echocardiogram (also known as echo). An echo is a noninvasive test that uses sound waves to evaluate your heart's chambers and valves, as well as its pumping function. The echo sound waves create an image on the monitor as an ultrasound probe is passed across the skin over your heart.

• Transesophageal echocardiogram (TEE). In this test, you will swallow a small probe, about the size of a little finger. The probe passes down the esophagus nearer to the heart. It allows a closer look at the heart's structure and function. It also shows any abnormal tissue around your heart valves, if blood is leaking backward through a valve, and if blood clots are present in your heart chambers.

• Positron emission tomography (PET) scan. This is a nuclear scan that gives information about the flow of blood through the coronary arteries to the heart muscle:

  • PET F-18 FDG (fluorodeoxyglucose) scan. This specialized PET scan uses a form of glucose to help determine if any specific areas of heart tissue have permanent damage. Your doctor may use it after a heart attack to determine which procedure, such as angioplasty, stenting, or bypass surgery, may be beneficial. Your doctor will inject a glucose solution through an IV into your blood. Then a special camera takes pictures of where the solution collects in your heart. 

• Thallium scans or myocardial perfusion scans. Similar to the PET scan, these tests involve an IV injection and a special camera:

  • Resting SPECT thallium scan or myocardial perfusion scan. A nuclear scan done while you rest. It is done to view areas of the heart muscle that are not getting enough blood.

  • Exercise thallium scan or myocardial perfusion scan. A nuclear scan is done while you are exercising. It is done to view areas of the heart muscle that are not getting enough blood during activity.

  • Adenosine or persantine thallium scan or myocardial perfusion scan. A nuclear scan done on if you are unable to exercise. It is done to view areas of the heart muscle that are not getting enough blood. It uses special medicines that stress the heart in the same way exercise does.

  • MUGA scans/radionuclide angiography (RNA) scans. Similar to the PET scan, these tests involve an IV injection and a special camera:

    • Resting gated blood pool scan (RGBPS), resting MUGA, or resting radionuclide angiography. A nuclear scan to evaluate how well the heart wall moves and how much blood is pumped with each heartbeat, while you rest.

    • Exercise gated blood pool scan, exercise MUGA, or exercise radionuclide angiography. A nuclear scan to evaluate how well the heart wall moves and how much blood is pumped with each heartbeat, just after you have walked on a treadmill or ridden on a stationary bike.

• Holter monitor. For this test, you wear a small, portable, battery-powered ECG machine to record heartbeats over a period of 24 to 48 hours during normal activities. At the end of the time period, you will return the monitor to the doctor's office so it can be read and evaluated.

• Event recorder. For this test, you wear a small, portable, battery-powered machine used to record ECG over several weeks. Each time you have symptoms, you press a button on the recorder to record the ECG sample. As soon as possible, you will transmit this sample to the doctor's office for evaluation.

• Loop recorder. Your doctor uses surgery to implant this device about the size of a zip drive under the skin to monitor and record the heartbeats for up to 2 years. 

• Tilt table test. Your doctor will connect you to an ECG and blood pressure monitor. Your will be strapped to a table that tilts you from a lying to standing position. This test is used to determine if you are prone to sudden drops in blood pressure (orthostatic hypotension), or slow pulse rates with position changes.

• Electrophysiology study. For this test, insulated electric catheters are placed through the large vein in the upper leg and thread into the heart. It is used to test the heart's electrical system to find irregular heart rhythms.

• Cardiac catheterization (also called coronary angiogram). For this test, your doctor guides a small catheter (hollow tube) through the large artery in your upper leg, or sometimes your wrist or arm, into your heart. Dye is given through the catheter, and moving X-ray pictures are made as the dye travels through your heart. This comprehensive test shows: narrowing in the arteries, heart chamber size, how well your heart pumps, and how well the valves open and close, as well as a measurement of the pressures within the heart chambers and arteries.

• Magnetic resonance imaging (MRI) of the heart. This procedure uses a combination of large magnets, radiofrequencies, and a computer to make detailed images of organs and structures in your body. Your doctor may use MRI of the heart to evaluate the heart valves and major vessels, detect coronary artery disease, and the extent of damage it has caused, evaluate congenital defects, and detect the presence of tumors or other abnormalities. Your doctor may do this test before other procedures such as angioplasty or stenting of the coronary arteries and heart or vascular surgery:

  • Magnetic resonance angiography (MRA) of the heart. This is a specialized type of MRI procedure used to evaluate blood vessels in your heart.

• Cardiac CT scan. This imaging procedure uses an X-ray machine and a computer to create a 3-dimensional pictures of the heart. Sometimes a dye is injected into a vein so that your heart arteries can be seen as well.