What is an EXERCISE ECG (Stress ECG)?
This is an electrocardiogram (ECG) that is recorded during exercise. The exercise may be done on an exercise bike, a treadmill or simply by jumping up and down a little stepladder or bench.
An exercise ECG provides more detailed information about the severity of the patients coronary heart disease.
Coronary heart disease usually causes chest pain or an uncomfortable sensation while doing the exercise. The stage of the exercise regime at which the patient develops chest pain, will indicate the degree of severity of the condition.
By monitoring the heart rate and observing when symptoms appear and when changes on the ECG occur, doctors can calculate the level of exercise that can be tolerated by the patient. This will assist the doctor to provide guidance regarding the patients rehabilitation program.
What happens during the test?
The technician will stick several small patches on the patients chest. These patches are connected to an ECG recorder by means of wires. The patient will be asked to start the exercise routine, either by riding the stationary bicycle, stepping up and down a bench or running on a treadmill.
The intensity of the test is increased during various stages (increments) of the test period and the patient will have to exercise at a faster pace.
During this time, the doctor carefully monitors the patients pulse, blood pressure, breathing and ECG readings. When sufficient data has been collected to make a complete evaluation (based on the test) of the patients condition, the doctor or technical assistant will inform the patient to stop exercising. This may be before the patient has completed the allocated exercise time, because of symptoms experienced by the patient or because of readings seen on the ECG.
The patient may also discontinue exercising at any time if they feel sick due to shortness of breath, chest pain or other symptoms. The total time for the exercise test is usually about 15 minutes. The test results have more value if the patient gives 100% during the test.
A stress echocardiogram or radionuclide test may be recommended by the specialist for patients with physical disabilities, joint or lung diseases who cannot perform the above-mentioned physical exercises.
How to prepare for the test?
- Do not eat a heavy meal for two hours before the test
- The patient should wear comfortable, loose-fitting clothing and running shoes
- Patients who take medications such as beta-blockers that may slow the heart rate (masking the effect of exercise on the heart) should discontinue the medication for at least two days before the test is done (this must be done in consultation with the patients doctor)
How does the test assist with making a diagnosis?
Changes in the heart pattern, as registered on the ECG during the exercise routine, assist doctors in evaluating the effects of heart disease.
The test also provides a good indication of the patients tolerance for exercise. Chest pain, symptoms of feeling sick and changes on the ECG graph at different stages of the exercise regime provide insight into the severity of the patients condition. If symptoms appear early in the exercise routine, the prognosis is worse than if symptoms appear at a later stage. The more strenuous exercise the patient can perform without experiencing symptoms, the better the prognosis.
Exercise ECG is a very valuable test for diagnosing coronary artery disease, but it is still not 100% accurate. In some instances, people with normal hearts will show a positive test (signs of coronary heart disease) and in others the results may be normal (negative), when the person actually do suffer from coronary heart disease.
© 2003 Prometheus™ Healthcare (Pty) Ltd