Measuring electrical activity not detected by plain ECG
This is a detailed type of electrocardiogram (ECG or EKG) that detects abnormalities in electrical conduction of the heart that a traditional ECG would not be able to detect. The signal-averaged electrocardiogram or SAECG is a noninvasive way to test heart function and also predict risk of a serious cardiac event. It can also be a predictor of future cardiac events after a person has had a heart attack. It may be useful for patients with conditions such as heart failure or cardiomyopathy who are at high risk for sudden cardiac death or ventricular arrhythmia.
Similar to a traditional ECG, small patches (electrodes) are placed at certain spots on the legs, arms and chest. The electrodes have wires that are connected to a machine that picks up the electrical activity of the heart. The machine records the electrical signals and patterns and the doctor examines the electrical activity. The test is painless and involves no special preparation. You may feel slight discomfort when the patches are removed from the skin and there may be minor skin irritation where the patches were.
SAECG is an outpatient procedure so you can go home afterwards and resume regular activity as soon as you like. Your doctor will discuss the results of the report with you and make any additional testing or treatment recommendations.