Drugs Information Online
Drugs and diseases reference index

Drugs and diseases reference index

Definition of «Stress testing, exercise cardiac»

Stress testing, exercise cardiac: The exercise cardiac stress testing (ECST) is the most widely used cardiac (heart) screening test. The patient exercises on a treadmill according to a standardized protocol, with progressive increases in the speed and elevation of the treadmill (typically changing at three-minute intervals). During the exercise cardiac stress testing (ECST), the patient's electrocardiogram (EKG), heart rate, heart rhythm, and blood pressure are continuously monitored.

If a coronary arterial blockage results in decreased blood flow to a part of the heart during exercise, certain changes may be observed in the EKG (the electrocardiogram), as well as in the response of the heart rate and blood pressure.

The accuracy of the ECST in predicting significant coronary artery disease (CAD) depends in part on the "pre-test likelihood" of CAD (also known as Bayes' theorem). In a patient at high risk for CAD (for example, because of advanced age or multiple coronary risk factors), an abnormal ECST is quite accurate (over 90% accurate) in predicting the presence of CAD. However, a relatively normal ECST may not mean there is an absence of significant coronary artery disease in a patient with the same high risk factors (so-called "false negative ECST").

In a patient at low risk for CAD, a normal ECST is quite accurate (over 90%) in predicting the absence of significant CAD. And an abnormal ECST test may not reflect the true presence of CAD (so-called "false-positive ECST").

The ECST may miss the presence of significant CAD and so give a false negative result. Or the ECST may indicate the presence of significant CAD when, in fact, there is none and so yield a false-positive test result. These false-negative and false-positive results are due to a variety of cardiac circumstances, which may include:

  1. An abnormal EKG at rest, which may be due to abnormal serum electrolytes, abnormal cardiac electrical conduction, or certain medications, such as digitalis;
  2. Heart conditions not related to CAD, such as mitral valve prolapse (drooping) or hypertrophy (increased size) of the heart; or
  3. An inadequate increase in the heart rate and/or blood pressure during exercise.

If the initial ECST does not clarify the diagnosis, additional tests are often used to clarify the condition. These further options include radionucleide isotope injection and ultrasound of the heart (stress echocardiography) during the stress test.

For More Information «Stress testing, exercise cardiac»

  • Cardiac stress testing - stress testing for the heart

    The Cardiac Stress Test Exercise testing for the heart. By Richard N. Fogoros, M.D., About.com Guide. Updated November 16, 2008. About.com Health's Disease and ...

  • Exercise stress test: MedlinePlus Medical Encyclopedia

    An exercise stress test is a screening tool used to test the effect of exercise on your heart. Stress tests are generally safe. Some patients may have ...

  • Cardiac Stress Testing - a knol by Eli Botvinick

    This Knol provides the practical, clinical, and scientific foundation needed to understand exercise testing and physician...

  • Treadmill Stress Test

    The patient walks on a treadmill while the blood pressure and EKG are monitored. The treadmill test evaluates the heart's response to exercise and helps uncover problems ...

  • Stress Test Intro

    Information about exercise stress testing in the diagnosis of heart disease. Explanations are provided to patients and their family in simplified terms and with the use ...