Signal Averaged Electrocardiogram (SA ECG)

The signal averaged electrocardiogram (ECG) is a special ECG that records the electrical activity of your heart over a period of 10 to 15 minutes. A computer scans the heartbeats for late electrical activity that occur after a normal contraction. This late electrical activity is a major cause of abnormal fast heartbeat which is not recorded by a normal ECG.

This test allows the doctor to identify patients at risk of a dangerous heart rhythm that may lead to sudden cardiac death.

There is no hospitalisation required.

Is the test safe?

There is no risk involved.

Preparations before test

You will be able to take your regular diet and medication. For male patients, you may be required to shave excessive hair on your chest.

How is the test done?

You will lie on a bed while the test is being performed. It is important that you lie as still as possible, breathe normally and do not talk during the procedure as the computer is very sensitive to movements, coughing and turning.

The medical technologist (MT) will place the electrodes on your chest and back to acquire the ECG. A special ECG machine will amplify and average the ECG signals until almost all noise is eliminated. Approximately 500 beats of the patient’s heart rate will be analysed by the computer and the doctor will then interpret the results.