• Pharmacological stress test (or chemical stress test). A type of stress test used with patients who are unable to perform physical activity. A drug such as dobutamine or adenosine is given to the patient, which causes the heart to react as if the person were exercising, even though the patient is actually at rest. Some drugs increase the heart rate, and other drugs increase blood flow by causing the coronary arteries to widen.

  • Stress echocardiogram. An echocardiogram is performed while the patient exercises in a controlled manner on a treadmill or stationary bicycle at varied speeds and elevations. The reaction of the heart under exertion can be measured, and the heart’s structure and function can be evaluated. This type of test can also be performed with the help of certain drugs that create stress in patients who are unable to exercise. 

  • Nuclear stress test. A stress test that is performed in conjunction with a nuclear imaging test, such as a SPECT scan or PET scan. In these tests, a radionuclide tracer is introduced into the bloodstream and the rate of uptake is monitored. In the case of a SPECT test, a special gamma camera will measure how quickly the radionuclide tracer is taken into heart muscle on a blood cell. In the case of a PET scan, special sensors measure how quickly a carrier molecule, usually glucose, is absorbed into the heart muscle. In either case, physicians are able to see how healthy heart muscle is by determining its ability to absorb blood or glucose. These tests are frequently ordered after a heart attack to help doctors determine how much of the heart tissue has been damaged, and whether damaged areas are truly dead or if they are stunned or hibernating. Because the overall radiation exposure is low, these tests are considered very safe.

    Echocardiogram