Signal-Averaged ECG 

An electrocardiogram (ECG or EKG) is a relatively quick, simple and effective way to evaluate heart function. A signal-averaged ECG is a more detailed type of electrocardiogram that can capture irregular heartbeats (arrhythmias) that may occur only intermittently and go undetected by a traditional ECG. 

Conditions Diagnosed 

A signal-averaged ECG is a non-invasive way to test heart function and evaluate the risk of a cardiac event, such as a heart attack or stroke. A physician may order this diagnostic test for a patient who has: 

  • Symptoms that may be heart-related, such as chest pain, shortness of breath, dizziness, fatigue or fainting 
  • Arrhythmias 
  • Heart failure 
  • Cardiomyopathy 

Procedure Details 

To prepare the patient for an ECG test, a technician will place several electrodes (small adhesive patches) on the patient’s chest, arms and legs, then connect the electrodes to an electrocardiogram machine via lead wires. The electrodes will record the electrical activity of the patient’s heart and send it to the ECG machine, which will measure, interpret and display the information in graphical format. 

During a signal-averaged ECG test, multiple ECG tracings will be obtained over approximately 20 minutes, which can help to ensure that any abnormal heartbeats that occur only sporadically are captured. 

What to Expect 

No advance preparation is needed for a signal-averaged CCG, and no special care is required afterward. After the test, most patients immediately resume their normal routines.


A signal-averaged ECG is a highly effective heart function test that can provide a physician with valuable information about the heart’s electrical conduction system. More detailed and refined than a traditional ECG, it can detect subtle and occasional abnormalities in the electrical activity of the heart.  

Tampa General Hospital’s Heart & Vascular Institute offers signal-averaged ECG and other advanced technologies used for diagnosing all types of heart disease.