Whilst the CTCA scan and coronary angiogram give anatomical information about the coronary arteries and any possible narrowing, stress echo looks at the functional performance of the muscle of the heart and by implication the coronary blood supply to the heart. This is achieved by exercising the heart either with physical exercise (eg treadmill or exercise bike) or in some situations by using a drug infusion to increase the heart rate. Stress echo does not use ionising radiation.
In Stress Echo the performance of the heart muscle is evaluated following exercise ‘stress’ and at rest. Failure of the muscle of the heart to pump harder during stress can suggest limitation in blood supply to the heart and the possible need for further tests.
A further useful function of stress echo scanning is in planning for operations since it is a non-invasive way of assessing the potential cardiac risk of non-cardiac surgery.
All test results should be treated with caution and interpreted in the context of a clinical assessment.